A short thick vein formed by union of the superior mesenteric vein and the splenic vein.
Abnormal increase of resistance to blood flow within the hepatic PORTAL SYSTEM, frequently seen in LIVER CIRRHOSIS and conditions with obstruction of the PORTAL VEIN.
A system of vessels in which blood, after passing through one capillary bed, is conveyed through a second set of capillaries before it returns to the systemic circulation. It pertains especially to the hepatic portal system.
The vessels carrying blood away from the capillary beds.
Veins which return blood from the intestines; the inferior mesenteric vein empties into the splenic vein, the superior mesenteric vein joins the splenic vein to form the portal vein.
The venous pressure measured in the PORTAL VEIN.
The circulation of BLOOD through the LIVER.
The vein which drains the foot and leg.
Veins which drain the liver.
Enlarged and tortuous VEINS.
A branch of the celiac artery that distributes to the stomach, pancreas, duodenum, liver, gallbladder, and greater omentum.
Vein formed by the union (at the hilus of the spleen) of several small veins from the stomach, pancreas, spleen and mesentery.
The vein accompanying the femoral artery in the same sheath; it is a continuation of the popliteal vein and becomes the external iliac vein.
The formation or presence of a blood clot (THROMBUS) within a vein.
Examination of the portal circulation by the use of X-ray films after injection of radiopaque material.
Veins in the neck which drain the brain, face, and neck into the brachiocephalic or subclavian veins.
The veins that return the oxygenated blood from the lungs to the left atrium of the heart.
Surgical venous shunt between the portal and systemic circulation to effect decompression of the portal circulation. It is performed primarily in the treatment of bleeding esophageal varices resulting from portal hypertension. Types of shunt include portacaval, splenorenal, mesocaval, splenocaval, left gastric-caval (coronary-caval), portarenal, umbilicorenal, and umbilicocaval.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
Short thick veins which return blood from the kidneys to the vena cava.
A vein on either side of the body which is formed by the union of the external and internal iliac veins and passes upward to join with its fellow of the opposite side to form the inferior vena cava.
Dilated blood vessels in the ESOPHAGUS or GASTRIC FUNDUS that shunt blood from the portal circulation (PORTAL SYSTEM) to the systemic venous circulation. Often they are observed in individuals with portal hypertension (HYPERTENSION, PORTAL).
Excision of all or part of the liver. (Dorland, 28th ed)
Venous vessels in the umbilical cord. They carry oxygenated, nutrient-rich blood from the mother to the FETUS via the PLACENTA. In humans, there is normally one umbilical vein.
Surgical portasystemic shunt between the portal vein and inferior vena cava.
Liver disease in which the normal microcirculation, the gross vascular anatomy, and the hepatic architecture have been variably destroyed and altered with fibrous septa surrounding regenerated or regenerating parenchymal nodules.
Tumors or cancer of the LIVER.
The transference of a part of or an entire liver from one human or animal to another.
Anastomosis of splenic vein to renal vein to relieve portal hypertension.
The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs.
Application of a ligature to tie a vessel or strangulate a part.
The circulation of blood through the BLOOD VESSELS supplying the abdominal VISCERA.
The vein formed by the union of the anterior and posterior tibial veins; it courses through the popliteal space and becomes the femoral vein.
A primary malignant neoplasm of epithelial liver cells. It ranges from a well-differentiated tumor with EPITHELIAL CELLS indistinguishable from normal HEPATOCYTES to a poorly differentiated neoplasm. The cells may be uniform or markedly pleomorphic, or form GIANT CELLS. Several classification schemes have been suggested.
A condition in which the hepatic venous outflow is obstructed anywhere from the small HEPATIC VEINS to the junction of the INFERIOR VENA CAVA and the RIGHT ATRIUM. Usually the blockage is extrahepatic and caused by blood clots (THROMBUS) or fibrous webs. Parenchymal FIBROSIS is uncommon.
The continuation of the axillary vein which follows the subclavian artery and then joins the internal jugular vein to form the brachiocephalic vein.
The blood pressure in the VEINS. It is usually measured to assess the filling PRESSURE to the HEART VENTRICLE.
The nonstriated involuntary muscle tissue of blood vessels.
The largest branch of the celiac trunk with distribution to the spleen, pancreas, stomach and greater omentum.
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.
Bleeding in any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM.
Veins draining the cerebrum.
A type of surgical portasystemic shunt to reduce portal hypertension with associated complications of esophageal varices and ascites. It is performed percutaneously through the jugular vein and involves the creation of an intrahepatic shunt between the hepatic vein and portal vein. The channel is maintained by a metallic stent. The procedure can be performed in patients who have failed sclerotherapy and is an additional option to the surgical techniques of portocaval, mesocaval, and splenorenal shunts. It takes one to three hours to perform. (JAMA 1995;273(23):1824-30)
A vein which arises from the right ascending lumbar vein or the vena cava, enters the thorax through the aortic orifice in the diaphragm, and terminates in the superior vena cava.
Surgical procedure involving either partial or entire removal of the spleen.
Formation and development of a thrombus or blood clot in the blood vessel.
Radiographic visualization or recording of a vein after the injection of contrast medium.
Surgical union or shunt between ducts, tubes or vessels. It may be end-to-end, end-to-side, side-to-end, or side-to-side.
A method of hemostasis utilizing various agents such as Gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and INTRACRANIAL ARTERIOVENOUS MALFORMATIONS, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage.
The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)
Pathological processes of the LIVER.
Central retinal vein and its tributaries. It runs a short course within the optic nerve and then leaves and empties into the superior ophthalmic vein or cavernous sinus.
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
Large veins on either side of the root of the neck formed by the junction of the internal jugular and subclavian veins. They drain blood from the head, neck, and upper extremities, and unite to form the superior vena cava.
Non-cadaveric providers of organs for transplant to related or non-related recipients.
Ultrasonography applying the Doppler effect, with the superposition of flow information as colors on a gray scale in a real-time image. This type of ultrasonography is well-suited to identifying the location of high-velocity flow (such as in a stenosis) or of mapping the extent of flow in a certain region.
Condition characterized by splenomegaly, some reduction in the number of circulating blood cells in the presence of a normal or hyperactive bone marrow, and the potential for reversal by splenectomy.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
Ultrasonography applying the Doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. (Stedman, 25th ed)
The inferior and superior venae cavae.
The venous trunk of the upper limb; a continuation of the basilar and brachial veins running from the lower border of the teres major muscle to the outer border of the first rib where it becomes the subclavian vein.
The flow of BLOOD through or around an organ or region of the body.
Radiography of blood vessels after injection of a contrast medium.
Liver diseases caused by infections with PARASITES, such as tapeworms (CESTODA) and flukes (TREMATODA).
Blockage of the RETINAL VEIN. Those at high risk for this condition include patients with HYPERTENSION; DIABETES MELLITUS; ATHEROSCLEROSIS; and other CARDIOVASCULAR DISEASES.
Administration of antineoplastic agents together with an embolizing vehicle. This allows slow release of the agent as well as obstruction of the blood supply to the neoplasm.
Elements of limited time intervals, contributing to particular results or situations.
The condition of an anatomical structure's being constricted beyond normal dimensions.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
The channels that collect and transport the bile secretion from the BILE CANALICULI, the smallest branch of the BILIARY TRACT in the LIVER, through the bile ductules, the bile ducts out the liver, and to the GALLBLADDER for storage.
Experimentally induced chronic injuries to the parenchymal cells in the liver to achieve a model for LIVER CIRRHOSIS.
A syndrome characterized by central nervous system dysfunction in association with LIVER FAILURE, including portal-systemic shunts. Clinical features include lethargy and CONFUSION (frequently progressing to COMA); ASTERIXIS; NYSTAGMUS, PATHOLOGIC; brisk oculovestibular reflexes; decorticate and decerebrate posturing; MUSCLE SPASTICITY; and bilateral extensor plantar reflexes (see REFLEX, BABINSKI). ELECTROENCEPHALOGRAPHY may demonstrate triphasic waves. (From Adams et al., Principles of Neurology, 6th ed, pp1117-20; Plum & Posner, Diagnosis of Stupor and Coma, 3rd ed, p222-5)
Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.
Repair or renewal of hepatic tissue.
Blood tests that are used to evaluate how well a patient's liver is working and also to help diagnose liver conditions.
Accumulation or retention of free fluid within the peritoneal cavity.
FIBROSIS of the hepatic parenchyma due to chronic excess ALCOHOL DRINKING.
A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
Enlargement of the spleen.
Treatment of varicose veins, hemorrhoids, gastric and esophageal varices, and peptic ulcer hemorrhage by injection or infusion of chemical agents which cause localized thrombosis and eventual fibrosis and obliteration of the vessels.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.

Twelfth rib resection as an approach for portal vein cannulation in sheep. (1/2024)

A surgical technique involving resection of the twelfth rib was used to insert silastic cannulas into the portal veins of three sheep to study amino acid metabolism. Good exposure to the vein was achieved by this method although it required positive ventilation due to the penetration of the thoracic cavity. All cannulas were buried subcutaneously and exteriorized near the dorsal midline. This facilitated continuous infusion into the portal cannula without disturbing cannula placement.  (+info)

Casts of hepatic blood vessels: a comparison of the microcirculation of the penguin, Pygoscelis adeliae, with some common laboratory animals. (2/2024)

Latex casts of the hepatic blood vessels of the penguin, Pygoscelis adeliae, and of some common laboratory animals were compared. There was general similarity between the different species, but the portal venous and hepatic arterial systems of the penguin were simpler than those of other species. Measurements were made of the volume and length of portal veins and it appears that the portal venous system is capable of being a more efficient blood reservoir in the penguin than in other species studied. The peribiliary plexus was especially well formed in the penguin and was drained by long veins which usually joined portal venous branches. Some of the long veins drained directly into the hepatic venous tree: these translobular veins were more prominent than in mammals. Anastomoses between hepatic artery and portal vein were not present in penguins, and the supply to the sinusoids appeared to be separate. The morphology of small hepatic veins of all the species appeared to be similar.  (+info)

Pulsed Doppler ultrasonographic evaluation of portal blood flow in dogs with experimental portal vein branch ligation. (3/2024)

Portal blood flow was measured using pulsed Doppler ultrasound in 6 dogs before and after left portal vein branch ligation. Mean portal vein blood flow velocity and mean portal vein blood flow were significantly reduced after ligation and the congestion index was increased (p < 0.01). Pulsed Doppler ultrasound studies provide valuable physiological information which may assist the clinician with the diagnosis of canine hepatic circulatory disorders.  (+info)

Identification, cloning and expression of rabbit vascular smooth muscle Kv1.5 and comparison with native delayed rectifier K+ current. (4/2024)

1. The molecular basis of voltage-gated, delayed rectifier K+ (KDR) channels in vascular smooth muscle cells is poorly defined. In this study we employed (i) an antibody against Kv1.5 and (ii) a cDNA clone encoding Kv1.5 derived from rabbit portal vein (RPV) to demonstrate Kv1.5 expression in RPV and to compare the properties of RPVKv1.5 expressed in mammalian cells with those of native RPV KDR current. 2. Expression of Kv1.5 channel protein in RPV was demonstrated by (i) immunocytolocalization of an antibody raised against a C-terminal epitope of mouse cardiac Kv1.5 in permeabilized, freshly isolated RPV smooth muscle cells and (ii) isolation of a cDNA clone encoding RPVKv1.5 by reverse transcription-polymerase chain reaction (RT-PCR) using mRNA derived from endothelium-denuded and adventitia-free RPV. 3. RPVKv1.5 cDNA was expressed in mammalian L cells and human embryonic kidney (HEK293) cells and the properties of the expressed channels compared with those of native KDR channels of freshly dispersed myocytes under identical conditions. 4. The kinetics and voltage dependence of activation of L cell-expressed RPVKv1.5 and native KDR current were identical, as were the kinetics of recovery from inactivation and single channel conductance. In contrast, there was little similarity between HEK293 cell-expressed RPVKv1.5 and native KDR current. 5. Inactivation occurred with the same voltage for half-maximal availability, but the kinetics and slope constant for the voltage dependence of inactivation for L cell-expressed RPVKv1.5 and the native current were different: slow time constants were 6.5 +/- 0.6 and 3.5 +/- 0.4 s and slope factors were 4.7 +/- 0.2 and 7.0 +/- 0.8 mV, respectively. 6. This study provides immunofluorescence and functional evidence that Kv1.5 alpha-subunits are a component of native KDR channels of vascular smooth muscle cells of RPV. However, the differences in kinetics and voltage sensitivity of inactivation between L cell- and HEK293 cell-expressed channels and native KDR channels provide functional evidence that vascular KDR current is not due to homomultimers of RPV Kv1.5 alone. The channel structure may be more complex, involving heteromultimers and modulatory Kvbeta-subunits, and/or native KDR current may have other components involving Kvalpha-subunits of other families.  (+info)

Factors mediating the hemodynamic effects of tumor necrosis factor-alpha in portal hypertensive rats. (5/2024)

Nitric oxide, prostacyclin, and glucagon have been implicated in promoting the hyperdynamic circulatory state of portal hypertension. Recent evidence also indicates that increased tumor necrosis factor-alpha (TNF-alpha) production is involved in the pathogenesis of this hemodynamic abnormality. This study was aimed at investigating in rats with portal vein stenosis (PVS) the effects on splanchnic hemodynamics of blocking circulating TNF-alpha and the factors mediating the vascular action of this cytokine in this setting. Anti-TNF-alpha polyclonal antibodies or placebo was injected into rats (n = 96) before and 4 days after PVS (short-term inhibition) and at 24 h and 4, 7, 10 days after PVS (long-term inhibition). Short-term TNF-alpha inhibition reduced portal venous inflow and cardiac index and increased splanchnic and systemic resistance. Portal pressure was unchanged, but portal-systemic shunting was decreased. After long-term TNF-alpha inhibition, portal venous inflow and portal pressure were unchanged, but arterial pressure and systemic resistance rose significantly. Anti-TNF-alpha PVS rats exhibited lower increments of systemic resistance after Nomega-nitro-L-arginine methyl ester and indomethacin administration and lower serum levels of TNF-alpha, nitrates-nitrites, and 6-keto-PGF1alpha, both over the short and the long term. Serum glucagon levels rose after long-term inhibition. In conclusion, the specific role played by TNF-alpha in the development of the hyperdynamic state of portal hypertension appears to be mainly mediated through an increased release of nitric oxide and prostacyclin. Maintenance of the splanchnic hyperemia after long-term TNF-alpha inhibition could be due to a compensatory release of glucagon.  (+info)

Lobar decrease in 99mTc-GSA accumulation in hilar cholangiocarcinoma. (6/2024)

Hilar cholangiocarcinoma can obstruct hepatic ducts and involve the portal veins. Both biliary stasis and decrease in portal venous flow are known to reduce 99mTc-diethylenetriamine pentaacetic acid-galactosyl human serum albumin (GSA) accumulation. The specific relationship between these pathological conditions due to hilar cholangiocarcinomas and 99mTc-GSA accumulation has never been clarified. METHODS: Sixteen patients with hilar cholangiocarcinomas who underwent 99mTc-GSA liver scintigraphy were reviewed. The relationship between significant decrease in 99mTc-GSA accumulation and lobar biliary stasis, or decrease in the portal venous flow, was evaluated. Average counts of region of interest placed in both right and left lobes were compared in the same transaxial SPECT section. Count ratios of right and left lobes were calculated. RESULTS: Significant lobar decrease in 99mTc-GSA accumulation was observed in 6 of the 16 patients. Ipsilateral portal venous stenosis or obstruction was seen in all these 6 patients, whereas ipsilateral portal venous stenosis or obstruction was seen in only 1 of the other 10 patients. Symmetric bile duct dilatation was seen in 13 patients, and asymmetric bile duct dilatation was seen in 3. Lobar decrease in 99mTc-GSA accumulation correlated well with decrease in ipsilateral portal venous flow (P < 0.0005). The count ratio was significantly reduced when unilateral portal venous flow decreased (P < 0.05). CONCLUSION: Using 99mTc-GSA liver scintigraphy, we can predict lobar decrease in ipsilateral portal venous flow and monitor hepatic functional lateralities in patients with hilar cholangiocarcinomas.  (+info)

Modulation of the decay of Ca2+-activated Cl- currents in rabbit portal vein smooth muscle cells by external anions. (7/2024)

1. The effects of external anions on the decay kinetics of Ca2+-activated Cl- currents (ICl(Ca)) were studied in smooth muscle cells isolated from rabbit portal vein using the perforated patch whole-cell voltage clamp technique. 2. In normal NaCl-containing external solution the decay of spontaneous Ca2+-activated Cl- currents (STICs) and Ca2+-activated Cl- 'tail' currents (Itail) was described by a single exponential with a time constant (tau) that was prolonged by external anions which are more permeable than Cl- (Br-, I- and SCN-) and accelerated by less permeant anions. However, intracellular I- did not affect the tau of STICs and Itail. 3. There was a positive correlation between the ability of an external anion to affect the decay tau of ICl(Ca) and its permeability relative to Cl-. 4. The voltage dependence of STIC and Itail decay was not affected by external or internal anions. 5. External permeating anions were not obligatory for activation of ICl(Ca) and STIC tau was not altered in Cl--free external solution. 6. Modulation of tau by mole fractions of SCN- and Cl- ions was fitted by a logistic curve, suggesting competition between SCN- and Cl- ions for a binding site. 7. In conclusion, external anions affect the decay of ICl(Ca) by a mechanism compatible with an interaction with a binding site which modulates Cl- channel kinetics.  (+info)

Specific galpha11beta3gamma5 protein involvement in endothelin receptor-induced phosphatidylinositol hydrolysis and Ca2+ release in rat portal vein myocytes. (8/2024)

In this study, we identified the receptor subtype activated by endothelin-1 (ET-1) and the subunit composition of the G protein coupling this receptor to increase in cytosolic Ca2+ concentration in rat portal vein myocytes. We used intranuclear antisense oligonucleotide injection to selectively inhibit the expression of G protein subunits. We show here that the endothelin receptor subtype A (ETA)-mediated increase in cytosolic Ca2+ concentration was mainly dependent on Ca2+ release from the intracellular store. ETA receptor-mediated Ca2+ release was selectively inhibited by antisense oligonucleotides that inhibited the expression of alpha11, beta3, and gamma5 subunits, as checked by immunocytochemistry. Intracellular dialysis of a carboxyl terminal anti-betacom antibody and a peptide corresponding to the Gbetagamma binding region of the beta-adrenergic receptor kinase-1 had no effect on the ETA receptor-mediated Ca2+ release. In contrast, a synthetic peptide corresponding to the carboxyl terminus of the alphaq/alpha11 subunit, heparin (an inhibitor of inositol 1,4,5-trisphosphate receptors), and U73122 (an inhibitor of phosphatidylinositol-phospholipase C) inhibited, in a concentration-dependent manner, the ETA receptor-mediated Ca2+ responses. Accumulation of [3H]inositol trisphosphate evoked by norepinephrine peaked at approximately 15 s, whereas that evoked by ET-1 progressively increased within 2 min. In myocytes injected with anti-alphaq antisense oligonucleotides, both amplitude and time course of the norepinephrine-induced Ca2+ release became similar to those of the ET-1-induced Ca2+ response. We conclude that the ETA receptor-mediated Ca2+ release is selectively transduced by the heterotrimeric G11 protein composed of alpha11, beta3, and gamma5 subunits, and that a delayed stimulation of phospholipase C occurs via the alpha11 subunit.  (+info)

The portal vein is the large venous trunk that carries blood from the gastrointestinal tract, spleen, pancreas, and gallbladder to the liver. It is formed by the union of the superior mesenteric vein (draining the small intestine and a portion of the large intestine) and the splenic vein (draining the spleen and pancreas). The portal vein then divides into right and left branches within the liver, where the blood flows through the sinusoids and gets enriched with oxygen and nutrients before being drained by the hepatic veins into the inferior vena cava. This unique arrangement allows the liver to process and detoxify the absorbed nutrients, remove waste products, and regulate metabolic homeostasis.

Portal hypertension is a medical condition characterized by an increased pressure in the portal vein, which is the large blood vessel that carries blood from the intestines, spleen, and pancreas to the liver. Normal portal venous pressure is approximately 5-10 mmHg. Portal hypertension is defined as a portal venous pressure greater than 10 mmHg.

The most common cause of portal hypertension is cirrhosis of the liver, which leads to scarring and narrowing of the small blood vessels in the liver, resulting in increased resistance to blood flow. Other causes include blood clots in the portal vein, inflammation of the liver or bile ducts, and invasive tumors that block the flow of blood through the liver.

Portal hypertension can lead to a number of complications, including the development of abnormal blood vessels (varices) in the esophagus, stomach, and intestines, which are prone to bleeding. Ascites, or the accumulation of fluid in the abdominal cavity, is another common complication of portal hypertension. Other potential complications include encephalopathy, which is a condition characterized by confusion, disorientation, and other neurological symptoms, and an increased risk of bacterial infections.

Treatment of portal hypertension depends on the underlying cause and the severity of the condition. Medications to reduce pressure in the portal vein, such as beta blockers or nitrates, may be used. Endoscopic procedures to band or inject varices can help prevent bleeding. In severe cases, surgery or liver transplantation may be necessary.

A portal system in medicine refers to a venous system in which veins from various tissues or organs (known as tributaries) drain into a common large vessel (known as the portal vein), which then carries the blood to a specific organ for filtration and processing before it is returned to the systemic circulation. The most well-known example of a portal system is the hepatic portal system, where veins from the gastrointestinal tract, spleen, pancreas, and stomach merge into the portal vein and then transport blood to the liver for detoxification and nutrient processing. Other examples include the hypophyseal portal system, which connects the hypothalamus to the anterior pituitary gland, and the renal portal system found in some animals.

Veins are blood vessels that carry deoxygenated blood from the tissues back to the heart. They have a lower pressure than arteries and contain valves to prevent the backflow of blood. Veins have a thin, flexible wall with a larger lumen compared to arteries, allowing them to accommodate more blood volume. The color of veins is often blue or green due to the absorption characteristics of light and the reduced oxygen content in the blood they carry.

The mesenteric veins are a set of blood vessels that are responsible for draining deoxygenated blood from the small and large intestines. There are two main mesenteric veins: the superior mesenteric vein and the inferior mesenteric vein. The superior mesenteric vein drains blood from the majority of the small intestine, as well as the ascending colon and proximal two-thirds of the transverse colon. The inferior mesenteric vein drains blood from the distal third of the transverse colon, descending colon, sigmoid colon, and rectum. These veins ultimately drain into the portal vein, which carries the blood to the liver for further processing.

Portal pressure, also known as portal hypertension, refers to an increase in the pressure within the portal vein, which is the large blood vessel that carries blood from the gastrointestinal tract and spleen to the liver. Normal portal pressure is usually between 5-10 mmHg.

Portal hypertension can occur as a result of various conditions that cause obstruction or narrowing of the portal vein, or increased resistance to blood flow within the liver. This can lead to the development of collateral vessels, which are abnormal blood vessels that form to bypass the blocked or narrowed vessel, and can result in complications such as variceal bleeding, ascites, and encephalopathy.

The measurement of portal pressure is often used in the diagnosis and management of patients with liver disease and portal hypertension.

Liver circulation, also known as hepatic circulation, refers to the blood flow through the liver. The liver receives blood from two sources: the hepatic artery and the portal vein.

The hepatic artery delivers oxygenated blood from the heart to the liver, accounting for about 25% of the liver's blood supply. The remaining 75% comes from the portal vein, which carries nutrient-rich, deoxygenated blood from the gastrointestinal tract, spleen, pancreas, and gallbladder to the liver.

In the liver, these two sources of blood mix in the sinusoids, small vessels with large spaces between the endothelial cells that line them. This allows for efficient exchange of substances between the blood and the hepatocytes (liver cells). The blood then leaves the liver through the hepatic veins, which merge into the inferior vena cava and return the blood to the heart.

The unique dual blood supply and extensive sinusoidal network in the liver enable it to perform various critical functions, such as detoxification, metabolism, synthesis, storage, and secretion of numerous substances, maintaining body homeostasis.

The saphenous vein is a term used in anatomical description to refer to the great or small saphenous veins, which are superficial veins located in the lower extremities of the human body.

The great saphenous vein (GSV) is the longest vein in the body and originates from the medial aspect of the foot, ascending along the medial side of the leg and thigh, and drains into the femoral vein at the saphenofemoral junction, located in the upper third of the thigh.

The small saphenous vein (SSV) is a shorter vein that originates from the lateral aspect of the foot, ascends along the posterior calf, and drains into the popliteal vein at the saphenopopliteal junction, located in the popliteal fossa.

These veins are often used as conduits for coronary artery bypass grafting (CABG) surgery due to their consistent anatomy and length.

The hepatic veins are blood vessels that carry oxygen-depleted blood from the liver back to the heart. There are typically three major hepatic veins - right, middle, and left - that originate from the posterior aspect of the liver and drain into the inferior vena cava just below the diaphragm. These veins are responsible for returning the majority of the blood flow from the gastrointestinal tract and spleen to the heart. It's important to note that the hepatic veins do not have valves, which can make them susceptible to a condition called Budd-Chiari syndrome, where blood clots form in the veins and obstruct the flow of blood from the liver.

Varicose veins are defined as enlarged, swollen, and twisting veins often appearing blue or dark purple, which usually occur in the legs. They are caused by weakened valves and vein walls that can't effectively push blood back toward the heart. This results in a buildup of blood, causing the veins to bulge and become varicose.

The condition is generally harmless but may cause symptoms like aching, burning, muscle cramp, or a feeling of heaviness in the legs. In some cases, varicose veins can lead to more serious problems, such as skin ulcers, blood clots, or chronic venous insufficiency. Treatment options include lifestyle changes, compression stockings, and medical procedures like sclerotherapy, laser surgery, or endovenous ablation.

The hepatic artery is a branch of the celiac trunk or abdominal aorta that supplies oxygenated blood to the liver. It typically divides into two main branches, the right and left hepatic arteries, which further divide into smaller vessels to supply different regions of the liver. The hepatic artery also gives off branches to supply other organs such as the gallbladder, pancreas, and duodenum.

It's worth noting that there is significant variability in the anatomy of the hepatic artery, with some individuals having additional branches or variations in the origin of the vessel. This variability can have implications for surgical procedures involving the liver and surrounding organs.

The splenic vein is a large, thin-walled vein that carries oxygenated blood from the spleen and pancreas to the liver. It is formed by the union of several smaller veins that drain the upper part of the stomach, the pancreas, and the left side of the colon (splenic flexure). The splenic vein runs along the top border of the pancreas and merges with the superior mesenteric vein to form the portal vein. This venous system allows for the filtration and detoxification of blood by the liver before it is distributed to the rest of the body.

The femoral vein is the large vein that runs through the thigh and carries oxygen-depleted blood from the lower limbs back to the heart. It is located in the femoral triangle, along with the femoral artery and nerve. The femoral vein begins at the knee as the popliteal vein, which then joins with the deep vein of the thigh to form the femoral vein. As it moves up the leg, it is joined by several other veins, including the great saphenous vein, before it becomes the external iliac vein at the inguinal ligament in the groin.

Venous thrombosis is a medical condition characterized by the formation of a blood clot (thrombus) in the deep veins, often in the legs (deep vein thrombosis or DVT), but it can also occur in other parts of the body such as the arms, pelvis, or lungs (pulmonary embolism).

The formation of a venous thrombus can be caused by various factors, including injury to the blood vessel wall, changes in blood flow, and alterations in the composition of the blood. These factors can lead to the activation of clotting factors and platelets, which can result in the formation of a clot that blocks the vein.

Symptoms of venous thrombosis may include swelling, pain, warmth, and redness in the affected area. In some cases, the clot can dislodge and travel to other parts of the body, causing potentially life-threatening complications such as pulmonary embolism.

Risk factors for venous thrombosis include advanced age, obesity, smoking, pregnancy, use of hormonal contraceptives or hormone replacement therapy, cancer, recent surgery or trauma, prolonged immobility, and a history of previous venous thromboembolism. Treatment typically involves the use of anticoagulant medications to prevent further clotting and dissolve existing clots.

Portography is a medical term that refers to an X-ray examination of the portal vein, which is the large blood vessel that carries blood from the digestive organs to the liver. In this procedure, a contrast dye is injected into the patient's veins, and then X-rays are taken to visualize the flow of the dye through the portal vein and its branches. This test can help diagnose various conditions that affect the liver and surrounding organs, such as cirrhosis, tumors, or blood clots in the portal vein. It is also known as a portovenogram or hepatic venography.

The jugular veins are a pair of large, superficial veins that carry blood from the head and neck to the heart. They are located in the neck and are easily visible when looking at the side of a person's neck. The external jugular vein runs along the surface of the muscles in the neck, while the internal jugular vein runs within the carotid sheath along with the carotid artery and the vagus nerve.

The jugular veins are important in clinical examinations because they can provide information about a person's cardiovascular function and intracranial pressure. For example, distention of the jugular veins may indicate heart failure or increased intracranial pressure, while decreased venous pulsations may suggest a low blood pressure or shock.

It is important to note that medical conditions such as deep vein thrombosis (DVT) can also affect the jugular veins and can lead to serious complications if not treated promptly.

Pulmonary veins are blood vessels that carry oxygenated blood from the lungs to the left atrium of the heart. There are four pulmonary veins in total, two from each lung, and they are the only veins in the body that carry oxygen-rich blood. The oxygenated blood from the pulmonary veins is then pumped by the left ventricle to the rest of the body through the aorta. Any blockage or damage to the pulmonary veins can lead to various cardiopulmonary conditions, such as pulmonary hypertension and congestive heart failure.

A portosystemic shunt is a surgical procedure that creates a connection between the portal vein (the blood vessel that carries blood from the digestive organs to the liver) and another systemic vein (a vein that carries blood away from the liver). This procedure is typically performed in animals, particularly dogs, to treat conditions such as portal hypertension or liver disease.

In a surgical portosystemic shunt, the surgeon creates a connection between the portal vein and a systemic vein, allowing blood from the digestive organs to bypass the liver. This can help to reduce the pressure in the portal vein and improve blood flow to the liver. The specific type of shunt created and the surgical approach used may vary depending on the individual patient's needs and the surgeon's preference.

It is important to note that while a surgical portosystemic shunt can be an effective treatment for certain conditions, it is not without risks and potential complications. As with any surgical procedure, there is always a risk of infection, bleeding, or other complications. Additionally, the creation of a portosystemic shunt can have long-term effects on the liver and overall health of the patient. It is important for pet owners to carefully consider the risks and benefits of this procedure and to discuss any questions or concerns they may have with their veterinarian.

The liver is a large, solid organ located in the upper right portion of the abdomen, beneath the diaphragm and above the stomach. It plays a vital role in several bodily functions, including:

1. Metabolism: The liver helps to metabolize carbohydrates, fats, and proteins from the food we eat into energy and nutrients that our bodies can use.
2. Detoxification: The liver detoxifies harmful substances in the body by breaking them down into less toxic forms or excreting them through bile.
3. Synthesis: The liver synthesizes important proteins, such as albumin and clotting factors, that are necessary for proper bodily function.
4. Storage: The liver stores glucose, vitamins, and minerals that can be released when the body needs them.
5. Bile production: The liver produces bile, a digestive juice that helps to break down fats in the small intestine.
6. Immune function: The liver plays a role in the immune system by filtering out bacteria and other harmful substances from the blood.

Overall, the liver is an essential organ that plays a critical role in maintaining overall health and well-being.

The renal veins are a pair of large veins that carry oxygen-depleted blood and waste products from the kidneys to the inferior vena cava, which is the largest vein in the body that returns blood to the heart. The renal veins are formed by the union of several smaller veins that drain blood from different parts of the kidney.

In humans, the right renal vein is shorter and passes directly into the inferior vena cava, while the left renal vein is longer and passes in front of the aorta before entering the inferior vena cava. The left renal vein also receives blood from the gonadal (testicular or ovarian) veins, suprarenal (adrenal) veins, and the lumbar veins.

It is important to note that the renal veins are vulnerable to compression by surrounding structures, such as the overlying artery or a tumor, which can lead to renal vein thrombosis, a serious condition that requires prompt medical attention.

The iliac veins are a pair of large veins in the human body that carry deoxygenated blood from the lower extremities and the pelvic area back to the heart. They are formed by the union of the common iliac veins, which receive blood from the lower abdomen and legs, at the level of the fifth lumbar vertebra.

The combined iliac vein is called the inferior vena cava, which continues upward to the right atrium of the heart. The iliac veins are located deep within the pelvis, lateral to the corresponding iliac arteries, and are accompanied by the iliac lymphatic vessels.

The left common iliac vein is longer than the right because it must cross the left common iliac artery to join the right common iliac vein. The external and internal iliac veins are the two branches of the common iliac vein, with the external iliac vein carrying blood from the lower limbs and the internal iliac vein carrying blood from the pelvic organs.

It is essential to maintain proper blood flow in the iliac veins to prevent deep vein thrombosis (DVT), a condition that can lead to serious complications such as pulmonary embolism.

Esophageal varices and gastric varices are abnormal, enlarged veins in the lower part of the esophagus (the tube that connects the throat to the stomach) and in the stomach lining, respectively. They occur as a result of increased pressure in the portal vein, which is the large blood vessel that carries blood from the digestive organs to the liver. This condition is known as portal hypertension.

Esophageal varices are more common than gastric varices and tend to be more symptomatic. They can cause bleeding, which can be life-threatening if not treated promptly. Gastric varices may also bleed, but they are often asymptomatic until they rupture.

The most common causes of esophageal and gastric varices are cirrhosis (scarring of the liver) and portal hypertension due to other liver diseases such as schistosomiasis or Budd-Chiari syndrome. Treatment options for esophageal and gastric varices include medications to reduce bleeding, endoscopic therapies to treat active bleeding or prevent recurrent bleeding, and surgical procedures to relieve portal hypertension.

Hepatectomy is a surgical procedure that involves the removal of part or all of the liver. This procedure can be performed for various reasons, such as removing cancerous or non-cancerous tumors, treating liver trauma, or donating a portion of the liver to another person in need of a transplant (live donor hepatectomy). The extent of the hepatectomy depends on the medical condition and overall health of the patient. It is a complex procedure that requires significant expertise and experience from the surgical team due to the liver's unique anatomy, blood supply, and regenerative capabilities.

The umbilical veins are blood vessels in the umbilical cord that carry oxygenated and nutrient-rich blood from the mother to the developing fetus during pregnancy. There are typically two umbilical veins, one of which usually degenerates and becomes obliterated, leaving a single functional vein. This remaining vein is known as the larger umbilical vein or the venous duct. It enters the fetal abdomen through the umbilicus and passes through the liver, where it branches off to form the portal sinus. Ultimately, the blood from the umbilical vein mixes with the blood from the inferior vena cava and is pumped to the heart through the right atrium.

It's important to note that after birth, the umbilical veins are no longer needed and undergo involution, becoming the ligamentum teres in the adult.

A portacaval shunt is a surgical procedure that creates an alternate pathway for blood flow between the portal vein and the inferior vena cava. The portal vein carries blood from the gastrointestinal tract, liver, spleen, and pancreas to the liver. In certain medical conditions, such as severe liver disease or portal hypertension, the blood pressure in the portal vein becomes abnormally high, which can lead to serious complications like variceal bleeding.

In a surgical portacaval shunt procedure, a surgeon creates a connection between the portal vein and the inferior vena cava, allowing a portion of the blood from the portal vein to bypass the liver and flow directly into the systemic circulation. This helps reduce the pressure in the portal vein and prevent complications associated with portal hypertension.

There are different types of portacaval shunts, including:

1. Direct portacaval shunt: In this procedure, the surgeon directly connects the portal vein to the inferior vena cava.
2. Side-to-side portacaval shunt: Here, the surgeon creates an anastomosis (connection) between a side branch of the portal vein and the inferior vena cava.
3. H-type shunt: This involves creating two separate connections between the portal vein and the inferior vena cava, forming an "H" shape.

It is important to note that while portacaval shunts can be effective in managing complications of portal hypertension, they may also have potential risks and side effects, such as worsening liver function, encephalopathy, or heart failure. Therefore, the decision to perform a portacaval shunt should be made carefully, considering the individual patient's medical condition and overall health.

Liver cirrhosis is a chronic, progressive disease characterized by the replacement of normal liver tissue with scarred (fibrotic) tissue, leading to loss of function. The scarring is caused by long-term damage from various sources such as hepatitis, alcohol abuse, nonalcoholic fatty liver disease, and other causes. As the disease advances, it can lead to complications like portal hypertension, fluid accumulation in the abdomen (ascites), impaired brain function (hepatic encephalopathy), and increased risk of liver cancer. It is generally irreversible, but early detection and treatment of underlying causes may help slow down its progression.

Liver neoplasms refer to abnormal growths in the liver that can be benign or malignant. Benign liver neoplasms are non-cancerous tumors that do not spread to other parts of the body, while malignant liver neoplasms are cancerous tumors that can invade and destroy surrounding tissue and spread to other organs.

Liver neoplasms can be primary, meaning they originate in the liver, or secondary, meaning they have metastasized (spread) to the liver from another part of the body. Primary liver neoplasms can be further classified into different types based on their cell of origin and behavior, including hepatocellular carcinoma, cholangiocarcinoma, and hepatic hemangioma.

The diagnosis of liver neoplasms typically involves a combination of imaging studies, such as ultrasound, CT scan, or MRI, and biopsy to confirm the type and stage of the tumor. Treatment options depend on the type and extent of the neoplasm and may include surgery, radiation therapy, chemotherapy, or liver transplantation.

Liver transplantation is a surgical procedure in which a diseased or failing liver is replaced with a healthy one from a deceased donor or, less commonly, a portion of a liver from a living donor. The goal of the procedure is to restore normal liver function and improve the patient's overall health and quality of life.

Liver transplantation may be recommended for individuals with end-stage liver disease, acute liver failure, certain genetic liver disorders, or liver cancers that cannot be treated effectively with other therapies. The procedure involves complex surgery to remove the diseased liver and implant the new one, followed by a period of recovery and close medical monitoring to ensure proper function and minimize the risk of complications.

The success of liver transplantation has improved significantly in recent years due to advances in surgical techniques, immunosuppressive medications, and post-transplant care. However, it remains a major operation with significant risks and challenges, including the need for lifelong immunosuppression to prevent rejection of the new liver, as well as potential complications such as infection, bleeding, and organ failure.

A splenorenal shunt is a surgical procedure that creates a connection between the spleen and the left kidney vein (renal vein). This type of shunt is typically performed to reroute the flow of blood from the spleen when there is an obstruction in the portal vein, which carries blood from the gastrointestinal tract, liver, and spleen. The procedure helps to alleviate portal hypertension (high blood pressure in the portal vein) and its complications, such as variceal bleeding (bleeding from enlarged veins in the esophagus or stomach).

During a surgical splenorenal shunt procedure, the surgeon will make an incision in the left flank region to access both the spleen and the left renal vein. The splenic vein is then divided, and one end is connected to the left renal vein using a synthetic graft or a portion of the patient's own blood vessel (autograft). This connection allows the blood from the spleen to bypass the obstructed portal vein and flow directly into the systemic venous circulation.

It is important to note that splenorenal shunts have been largely replaced by transjugular intrahepatic portosystemic shunts (TIPS) as the first-line treatment for managing portal hypertension due to their lower invasiveness and fewer complications. However, surgical splenorenal shunts may still be considered in specific cases where TIPS is not feasible or has failed.

The inferior vena cava (IVC) is the largest vein in the human body that carries deoxygenated blood from the lower extremities, pelvis, and abdomen to the right atrium of the heart. It is formed by the union of the left and right common iliac veins at the level of the fifth lumbar vertebra. The inferior vena cava is a retroperitoneal structure, meaning it lies behind the peritoneum, the lining that covers the abdominal cavity. It ascends through the posterior abdominal wall and passes through the central tendon of the diaphragm to enter the thoracic cavity.

The inferior vena cava is composed of three parts:

1. The infrarenal portion, which lies below the renal veins
2. The renal portion, which receives blood from the renal veins
3. The suprahepatic portion, which lies above the liver and receives blood from the hepatic veins before draining into the right atrium of the heart.

The inferior vena cava plays a crucial role in maintaining venous return to the heart and contributing to cardiovascular function.

Ligation, in the context of medical terminology, refers to the process of tying off a part of the body, usually blood vessels or tissue, with a surgical suture or another device. The goal is to stop the flow of fluids such as blood or other substances within the body. It is commonly used during surgeries to control bleeding or to block the passage of fluids, gases, or solids in various parts of the body.

Splanchnic circulation refers to the blood flow to the visceral organs, including the gastrointestinal tract, pancreas, spleen, and liver. These organs receive a significant portion of the cardiac output, with approximately 25-30% of the total restingly going to the splanchnic circulation. The splanchnic circulation is regulated by a complex interplay of neural and hormonal mechanisms that help maintain adequate blood flow to these vital organs while also allowing for the distribution of blood to other parts of the body as needed.

The splanchnic circulation is unique in its ability to vasodilate and increase blood flow significantly in response to meals or other stimuli, such as stress or hormonal changes. This increased blood flow helps support the digestive process and absorption of nutrients. At the same time, the body must carefully regulate this blood flow to prevent a significant drop in blood pressure or overloading the heart with too much work.

Overall, the splanchnic circulation plays a critical role in maintaining the health and function of the body's vital organs, and dysregulation of this system can contribute to various diseases, including digestive disorders, liver disease, and cardiovascular disease.

The popliteal vein is the continuation of the tibial and fibular (or anterior and posterior tibial) veins, forming in the lower leg's back portion or popliteal fossa. It carries blood from the leg towards the heart. The popliteal vein is located deep within the body and is accompanied by the popliteal artery, which supplies oxygenated blood to the lower leg. This venous structure is a crucial part of the venous system in the lower extremities and is often assessed during physical examinations for signs of venous insufficiency or deep vein thrombosis (DVT).

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults. It originates from the hepatocytes, which are the main functional cells of the liver. This type of cancer is often associated with chronic liver diseases such as cirrhosis caused by hepatitis B or C virus infection, alcohol abuse, non-alcoholic fatty liver disease (NAFLD), and aflatoxin exposure.

The symptoms of HCC can vary but may include unexplained weight loss, lack of appetite, abdominal pain or swelling, jaundice, and fatigue. The diagnosis of HCC typically involves imaging tests such as ultrasound, CT scan, or MRI, as well as blood tests to measure alpha-fetoprotein (AFP) levels. Treatment options for Hepatocellular carcinoma depend on the stage and extent of the cancer, as well as the patient's overall health and liver function. Treatment options may include surgery, radiation therapy, chemotherapy, targeted therapy, or liver transplantation.

Budd-Chiari syndrome is a rare condition characterized by the obstruction of the hepatic veins, which are the blood vessels that carry blood from the liver to the heart. This obstruction can be caused by blood clots, tumors, or other abnormalities, and it can lead to a backflow of blood in the liver, resulting in various symptoms such as abdominal pain, swelling, and liver enlargement. In severe cases, Budd-Chiari syndrome can cause liver failure and other complications if left untreated. The diagnosis of this condition typically involves imaging tests such as ultrasound, CT scan, or MRI, and treatment may include anticoagulation therapy, thrombolytic therapy, or surgical intervention to remove the obstruction.

The subclavian vein is a large venous structure that carries deoxygenated blood from the upper limb and part of the thorax back to the heart. It forms when the axillary vein passes through the narrow space between the first rib and the clavicle (collarbone), becoming the subclavian vein.

On the left side, the subclavian vein joins with the internal jugular vein to form the brachiocephalic vein, while on the right side, the subclavian vein directly merges with the internal jugular vein to create the brachiocephalic vein. These brachiocephalic veins then unite to form the superior vena cava, which drains blood into the right atrium of the heart.

The subclavian vein is an essential structure for venous access in various medical procedures and interventions, such as placing central venous catheters or performing blood tests.

Venous pressure is the pressure exerted on the walls of a vein, which varies depending on several factors such as the volume and flow of blood within the vein, the contractile state of the surrounding muscles, and the position of the body. In clinical settings, venous pressure is often measured in the extremities (e.g., arms or legs) to assess the functioning of the cardiovascular system.

Central venous pressure (CVP) is a specific type of venous pressure that refers to the pressure within the large veins that enter the right atrium of the heart. CVP is an important indicator of right heart function and fluid status, as it reflects the amount of blood returning to the heart and the ability of the heart to pump it forward. Normal CVP ranges from 0 to 8 mmHg (millimeters of mercury) in adults.

Elevated venous pressure can be caused by various conditions such as heart failure, obstruction of blood flow, or fluid overload, while low venous pressure may indicate dehydration or blood loss. Accurate measurement and interpretation of venous pressure require specialized equipment and knowledge, and are typically performed by healthcare professionals in a clinical setting.

A smooth muscle within the vascular system refers to the involuntary, innervated muscle that is found in the walls of blood vessels. These muscles are responsible for controlling the diameter of the blood vessels, which in turn regulates blood flow and blood pressure. They are called "smooth" muscles because their individual muscle cells do not have the striations, or cross-striped patterns, that are observed in skeletal and cardiac muscle cells. Smooth muscle in the vascular system is controlled by the autonomic nervous system and by hormones, and can contract or relax slowly over a period of time.

The splenic artery is the largest branch of the celiac trunk, which arises from the abdominal aorta. It supplies blood to the spleen and several other organs in the upper left part of the abdomen. The splenic artery divides into several branches that ultimately form a network of capillaries within the spleen. These capillaries converge to form the main venous outflow, the splenic vein, which drains into the hepatic portal vein.

The splenic artery is a vital structure in the human body, and any damage or blockage can lead to serious complications, including splenic infarction (reduced blood flow to the spleen) or splenic rupture (a surgical emergency that can be life-threatening).

X-ray computed tomography (CT or CAT scan) is a medical imaging method that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of the body. These cross-sectional images can then be used to display detailed internal views of organs, bones, and soft tissues in the body.

The term "computed tomography" is used instead of "CT scan" or "CAT scan" because the machines take a series of X-ray measurements from different angles around the body and then use a computer to process these data to create detailed images of internal structures within the body.

CT scanning is a noninvasive, painless medical test that helps physicians diagnose and treat medical conditions. CT imaging provides detailed information about many types of tissue including lung, bone, soft tissue and blood vessels. CT examinations can be performed on every part of the body for a variety of reasons including diagnosis, surgical planning, and monitoring of therapeutic responses.

In computed tomography (CT), an X-ray source and detector rotate around the patient, measuring the X-ray attenuation at many different angles. A computer uses this data to construct a cross-sectional image by the process of reconstruction. This technique is called "tomography". The term "computed" refers to the use of a computer to reconstruct the images.

CT has become an important tool in medical imaging and diagnosis, allowing radiologists and other physicians to view detailed internal images of the body. It can help identify many different medical conditions including cancer, heart disease, lung nodules, liver tumors, and internal injuries from trauma. CT is also commonly used for guiding biopsies and other minimally invasive procedures.

In summary, X-ray computed tomography (CT or CAT scan) is a medical imaging technique that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional images of the body. It provides detailed internal views of organs, bones, and soft tissues in the body, allowing physicians to diagnose and treat medical conditions.

Gastrointestinal (GI) hemorrhage is a term used to describe any bleeding that occurs in the gastrointestinal tract, which includes the esophagus, stomach, small intestine, large intestine, and rectum. The bleeding can range from mild to severe and can produce symptoms such as vomiting blood, passing black or tarry stools, or having low blood pressure.

GI hemorrhage can be classified as either upper or lower, depending on the location of the bleed. Upper GI hemorrhage refers to bleeding that occurs above the ligament of Treitz, which is a point in the small intestine where it becomes narrower and turns a corner. Common causes of upper GI hemorrhage include gastritis, ulcers, esophageal varices, and Mallory-Weiss tears.

Lower GI hemorrhage refers to bleeding that occurs below the ligament of Treitz. Common causes of lower GI hemorrhage include diverticulosis, colitis, inflammatory bowel disease, and vascular abnormalities such as angiodysplasia.

The diagnosis of GI hemorrhage is often made based on the patient's symptoms, medical history, physical examination, and diagnostic tests such as endoscopy, CT scan, or radionuclide scanning. Treatment depends on the severity and cause of the bleeding and may include medications, endoscopic procedures, surgery, or a combination of these approaches.

Cerebral veins are the blood vessels that carry deoxygenated blood from the brain to the dural venous sinuses, which are located between the layers of tissue covering the brain. The largest cerebral vein is the superior sagittal sinus, which runs along the top of the brain. Other major cerebral veins include the straight sinus, transverse sinus, sigmoid sinus, and cavernous sinus. These veins receive blood from smaller veins called venules that drain the surface and deep structures of the brain. The cerebral veins play an important role in maintaining normal circulation and pressure within the brain.

A Transjugular Intrahepatic Portosystemic Shunt (TIPS) is a medical procedure that creates an alternative pathway for blood flow from the portal vein to the hepatic vein within the liver. This shunt is composed of a stent, which is a small metal tube that is inserted into the liver using a long needle that is passed through a vein in the neck (jugular vein).

TIPS is typically used to treat complications of portal hypertension, such as variceal bleeding, ascites, and hepatic hydrothorax. By creating a shunt that bypasses the liver, TIPS reduces the pressure in the portal vein, which can help to alleviate these symptoms. However, because the shunt allows blood to bypass the liver, it can also impair liver function and lead to other complications, such as hepatic encephalopathy.

It is important to note that TIPS is a complex procedure that should only be performed by experienced interventional radiologists in a hospital setting with appropriate medical backup and monitoring capabilities.

The azygos vein is a large, unpaired venous structure in the thoracic cavity of the human body. It begins as the ascending lumbar vein, which receives blood from the lower extremities and abdominal organs. As it enters the thorax through the diaphragm, it becomes the azygos vein and continues to ascend along the vertebral column.

The azygos vein receives blood from various tributaries, including the intercostal veins, esophageal veins, mediastinal veins, and bronchial veins. It then arches over the right mainstem bronchus and empties into the superior vena cava, which returns blood to the right atrium of the heart.

The azygos vein provides an important collateral pathway for venous return in cases where the inferior vena cava is obstructed or occluded. It also plays a role in the spread of certain thoracic diseases, such as tuberculosis and cancer.

A splenectomy is a surgical procedure in which the spleen is removed from the body. The spleen is an organ located in the upper left quadrant of the abdomen, near the stomach and behind the ribs. It plays several important roles in the body, including fighting certain types of infections, removing old or damaged red blood cells from the circulation, and storing platelets and white blood cells.

There are several reasons why a splenectomy may be necessary, including:

* Trauma to the spleen that cannot be repaired
* Certain types of cancer, such as Hodgkin's lymphoma or non-Hodgkin's lymphoma
* Sickle cell disease, which can cause the spleen to enlarge and become damaged
* A ruptured spleen, which can be life-threatening if not treated promptly
* Certain blood disorders, such as idiopathic thrombocytopenic purpura (ITP) or hemolytic anemia

A splenectomy is typically performed under general anesthesia and may be done using open surgery or laparoscopically. After the spleen is removed, the incision(s) are closed with sutures or staples. Recovery time varies depending on the individual and the type of surgery performed, but most people are able to return to their normal activities within a few weeks.

It's important to note that following a splenectomy, individuals may be at increased risk for certain types of infections, so it's recommended that they receive vaccinations to help protect against these infections. They should also seek medical attention promptly if they develop fever, chills, or other signs of infection.

Thrombosis is the formation of a blood clot (thrombus) inside a blood vessel, obstructing the flow of blood through the circulatory system. When a clot forms in an artery, it can cut off the supply of oxygen and nutrients to the tissues served by that artery, leading to damage or tissue death. If a thrombus forms in the heart, it can cause a heart attack. If a thrombus breaks off and travels through the bloodstream, it can lodge in a smaller vessel, causing blockage and potentially leading to damage in the organ that the vessel supplies. This is known as an embolism.

Thrombosis can occur due to various factors such as injury to the blood vessel wall, abnormalities in blood flow, or changes in the composition of the blood. Certain medical conditions, medications, and lifestyle factors can increase the risk of thrombosis. Treatment typically involves anticoagulant or thrombolytic therapy to dissolve or prevent further growth of the clot, as well as addressing any underlying causes.

Phlebography is a medical imaging technique used to visualize and assess the veins, particularly in the legs. It involves the injection of a contrast agent into the veins, followed by X-ray imaging to capture the flow of the contrast material through the veins. This allows doctors to identify any abnormalities such as blood clots, blockages, or malformations in the venous system.

There are different types of phlebography, including ascending phlebography (where the contrast agent is injected into a foot vein and travels up the leg) and descending phlebography (where the contrast agent is injected into a vein in the groin or neck and travels down the leg).

Phlebography is an invasive procedure that requires careful preparation and monitoring, and it is typically performed by radiologists or vascular specialists. It has largely been replaced by non-invasive imaging techniques such as ultrasound and CT angiography in many clinical settings.

Surgical anastomosis is a medical procedure that involves the connection of two tubular structures, such as blood vessels or intestines, to create a continuous passage. This technique is commonly used in various types of surgeries, including vascular, gastrointestinal, and orthopedic procedures.

During a surgical anastomosis, the ends of the two tubular structures are carefully prepared by removing any damaged or diseased tissue. The ends are then aligned and joined together using sutures, staples, or other devices. The connection must be secure and leak-free to ensure proper function and healing.

The success of a surgical anastomosis depends on several factors, including the patient's overall health, the location and condition of the structures being joined, and the skill and experience of the surgeon. Complications such as infection, bleeding, or leakage can occur, which may require additional medical intervention or surgery.

Proper postoperative care is also essential to ensure the success of a surgical anastomosis. This may include monitoring for signs of complications, administering medications to prevent infection and promote healing, and providing adequate nutrition and hydration.

Therapeutic embolization is a medical procedure that involves intentionally blocking or obstructing blood vessels to stop excessive bleeding or block the flow of blood to a tumor or abnormal tissue. This is typically accomplished by injecting small particles, such as microspheres or coils, into the targeted blood vessel through a catheter, which is inserted into a larger blood vessel and guided to the desired location using imaging techniques like X-ray or CT scanning. The goal of therapeutic embolization is to reduce the size of a tumor, control bleeding, or block off abnormal blood vessels that are causing problems.

I believe there might be a misunderstanding in your question. "Dogs" is not a medical term or condition. It is the common name for a domesticated carnivore of the family Canidae, specifically the genus Canis, which includes wolves, foxes, and other extant and extinct species of mammals. Dogs are often kept as pets and companions, and they have been bred in a wide variety of forms and sizes for different purposes, such as hunting, herding, guarding, assisting police and military forces, and providing companionship and emotional support.

If you meant to ask about a specific medical condition or term related to dogs, please provide more context so I can give you an accurate answer.

Liver diseases refer to a wide range of conditions that affect the normal functioning of the liver. The liver is a vital organ responsible for various critical functions such as detoxification, protein synthesis, and production of biochemicals necessary for digestion.

Liver diseases can be categorized into acute and chronic forms. Acute liver disease comes on rapidly and can be caused by factors like viral infections (hepatitis A, B, C, D, E), drug-induced liver injury, or exposure to toxic substances. Chronic liver disease develops slowly over time, often due to long-term exposure to harmful agents or inherent disorders of the liver.

Common examples of liver diseases include hepatitis, cirrhosis (scarring of the liver tissue), fatty liver disease, alcoholic liver disease, autoimmune liver diseases, genetic/hereditary liver disorders (like Wilson's disease and hemochromatosis), and liver cancers. Symptoms may vary widely depending on the type and stage of the disease but could include jaundice, abdominal pain, fatigue, loss of appetite, nausea, and weight loss.

Early diagnosis and treatment are essential to prevent progression and potential complications associated with liver diseases.

A Retinal Vein is a vessel that carries oxygen-depleted blood away from the retina, a light-sensitive layer at the back of the eye. The retinal veins originate from a network of smaller vessels called venules and ultimately merge to form the central retinal vein, which exits the eye through the optic nerve.

Retinal veins are crucial for maintaining the health and function of the retina, as they facilitate the removal of waste products and help regulate the ocular environment. However, they can also be susceptible to various pathological conditions such as retinal vein occlusions, which can lead to vision loss or damage to the eye.

Treatment outcome is a term used to describe the result or effect of medical treatment on a patient's health status. It can be measured in various ways, such as through symptoms improvement, disease remission, reduced disability, improved quality of life, or survival rates. The treatment outcome helps healthcare providers evaluate the effectiveness of a particular treatment plan and make informed decisions about future care. It is also used in clinical research to compare the efficacy of different treatments and improve patient care.

The brachiocephalic veins, also known as the innominate veins, are large veins in the human body. They are formed by the union of the subclavian vein and the internal jugular vein on each side of the body. The resulting vein then carries blood from the upper limbs, head, and neck to the superior vena cava, which is the large vein that returns blood to the heart.

Here's a more detailed medical definition:

The brachiocephalic veins are paired venous structures that result from the union of the subclavian vein and the internal jugular vein on each side of the body. These veins are located in the superior mediastinum, near the base of the neck, and are typically about 2 to 3 centimeters in length. The brachiocephalic veins receive blood from several sources, including the upper extremities, head, neck, and thoracic wall. They then transport this blood to the superior vena cava, which is a large vein that returns blood to the right atrium of the heart.

It's worth noting that the brachiocephalic veins are subject to various pathological conditions, including thrombosis (blood clots), stenosis (narrowing), and compression by nearby structures such as the first rib or the scalene muscles. These conditions can lead to a variety of symptoms, including swelling, pain, and difficulty breathing.

A living donor is a person who voluntarily donates an organ or part of an organ to another person while they are still alive. This can include donations such as a kidney, liver lobe, lung, or portion of the pancreas or intestines. The donor and recipient typically undergo medical evaluation and compatibility testing to ensure the best possible outcome for the transplantation procedure. Living donation is regulated by laws and ethical guidelines to ensure that donors are fully informed and making a voluntary decision.

Ultrasonography, Doppler, color is a type of diagnostic ultrasound technique that uses the Doppler effect to produce visual images of blood flow in vessels and the heart. The Doppler effect is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the source of the wave. In this context, it refers to the change in frequency of the ultrasound waves as they reflect off moving red blood cells.

In color Doppler ultrasonography, different colors are used to represent the direction and speed of blood flow. Red typically represents blood flowing toward the transducer (the device that sends and receives sound waves), while blue represents blood flowing away from the transducer. The intensity or brightness of the color is proportional to the velocity of blood flow.

Color Doppler ultrasonography is often used in conjunction with grayscale ultrasound imaging, which provides information about the structure and composition of tissues. Together, these techniques can help diagnose a wide range of conditions, including heart disease, blood clots, and abnormalities in blood flow.

Hypersplenism is a condition characterized by an enlarged spleen (splenomegaly) that results in the abnormal removal or destruction of various blood components, such as red blood cells (RBCs), white blood cells (WBCs), and platelets. This leads to peripheral blood cytopenias, which means there is a decrease in one or more types of blood cells in the circulation.

The spleen becomes overactive in hypersplenism, and its increased removal of blood cells can be secondary to various underlying disorders, such as:

1. Infections: e.g., bacterial endocarditis, malaria, or EBV (Epstein-Barr virus) infection
2. Hematologic diseases: e.g., hemolytic anemias, thalassemia, leukemias, lymphomas, or myeloproliferative neoplasms
3. Cirrhosis and portal hypertension
4. Vascular disorders: e.g., splenic vein thrombosis or congestive splenomegaly
5. Storage diseases: e.g., Gaucher's disease, Niemann-Pick disease, or Hurler syndrome

Symptoms of hypersplenism may include fatigue, weakness, pallor (in case of anemia), infections (due to neutropenia), and easy bruising or bleeding (due to thrombocytopenia). Treatment for hypersplenism involves addressing the underlying cause. In some cases, splenectomy (surgical removal of the spleen) may be considered if the benefits outweigh the risks.

Norepinephrine, also known as noradrenaline, is a neurotransmitter and a hormone that is primarily produced in the adrenal glands and is released into the bloodstream in response to stress or physical activity. It plays a crucial role in the "fight-or-flight" response by preparing the body for action through increasing heart rate, blood pressure, respiratory rate, and glucose availability.

As a neurotransmitter, norepinephrine is involved in regulating various functions of the nervous system, including attention, perception, motivation, and arousal. It also plays a role in modulating pain perception and responding to stressful or emotional situations.

In medical settings, norepinephrine is used as a vasopressor medication to treat hypotension (low blood pressure) that can occur during septic shock, anesthesia, or other critical illnesses. It works by constricting blood vessels and increasing heart rate, which helps to improve blood pressure and perfusion of vital organs.

Ultrasonography, Doppler refers to a non-invasive diagnostic medical procedure that uses high-frequency sound waves to create real-time images of the movement of blood flow through vessels, tissues, or heart valves. The Doppler effect is used to measure the frequency shift of the ultrasound waves as they bounce off moving red blood cells, which allows for the calculation of the speed and direction of blood flow. This technique is commonly used to diagnose and monitor various conditions such as deep vein thrombosis, carotid artery stenosis, heart valve abnormalities, and fetal heart development during pregnancy. It does not use radiation or contrast agents and is considered safe with minimal risks.

"Venae Cavae" is a term that refers to the two large veins in the human body that return deoxygenated blood from the systemic circulation to the right atrium of the heart.

The "Superior Vena Cava" receives blood from the upper half of the body, including the head, neck, upper limbs, and chest, while the "Inferior Vena Cava" collects blood from the lower half of the body, including the abdomen and lower limbs.

Together, these veins play a crucial role in the circulatory system by ensuring that oxygen-depleted blood is efficiently returned to the heart for reoxygenation in the lungs.

The axillary vein is a large vein that runs through the axilla or armpit region. It is formed by the union of the brachial vein and the basilic vein at the lower border of the teres major muscle. The axillary vein carries deoxygenated blood from the upper limb, chest wall, and breast towards the heart. As it moves proximally, it becomes continuous with the subclavian vein to form the brachiocephalic vein. It is accompanied by the axillary artery and forms part of the important neurovascular bundle in the axilla.

Regional blood flow (RBF) refers to the rate at which blood flows through a specific region or organ in the body, typically expressed in milliliters per minute per 100 grams of tissue (ml/min/100g). It is an essential physiological parameter that reflects the delivery of oxygen and nutrients to tissues while removing waste products. RBF can be affected by various factors such as metabolic demands, neural regulation, hormonal influences, and changes in blood pressure or vascular resistance. Measuring RBF is crucial for understanding organ function, diagnosing diseases, and evaluating the effectiveness of treatments.

Angiography is a medical procedure in which an x-ray image is taken to visualize the internal structure of blood vessels, arteries, or veins. This is done by injecting a radiopaque contrast agent (dye) into the blood vessel using a thin, flexible catheter. The dye makes the blood vessels visible on an x-ray image, allowing doctors to diagnose and treat various medical conditions such as blockages, narrowing, or malformations of the blood vessels.

There are several types of angiography, including:

* Cardiac angiography (also called coronary angiography) - used to examine the blood vessels of the heart
* Cerebral angiography - used to examine the blood vessels of the brain
* Peripheral angiography - used to examine the blood vessels in the limbs or other parts of the body.

Angiography is typically performed by a radiologist, cardiologist, or vascular surgeon in a hospital setting. It can help diagnose conditions such as coronary artery disease, aneurysms, and peripheral arterial disease, among others.

Parasitic liver diseases refer to conditions caused by protozoa or helminths (parasitic worms) that infect and damage the liver. These parasites can enter the body through contaminated food, water, or direct contact with an infected host. Some examples of parasitic liver diseases include:

1. Ascariasis: Caused by the roundworm Ascaris lumbricoides, which can infect the liver and bile ducts, leading to inflammation, obstruction, and abscess formation.
2. Echinococcosis (Hydatid disease): A rare but serious condition caused by the larval stage of tapeworms from the genus Echinococcus. The liver is the most commonly affected organ, with cysts forming in the liver parenchyma that can grow slowly over several years and cause complications such as rupture or secondary bacterial infection.
3. Fascioliasis: A foodborne trematode (fluke) infection caused by Fasciola hepatica or Fasciola gigantica, which affects the liver and bile ducts. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
4. Leishmaniasis: A protozoan infection caused by Leishmania spp., which can affect various organs, including the liver. Visceral leishmaniasis (kala-azar) is the most severe form of the disease, characterized by hepatosplenomegaly, fever, and anemia.
5. Toxoplasmosis: A protozoan infection caused by Toxoplasma gondii, which can affect the liver and other organs. While most immunocompetent individuals remain asymptomatic or experience mild flu-like symptoms, immunocompromised patients are at risk of severe liver damage and disseminated disease.
6. Schistosomiasis: A trematode (fluke) infection caused by Schistosoma spp., which affects the liver and portal venous system. The parasites lay eggs in the liver, causing granulomatous inflammation, fibrosis, and portal hypertension.
7. Fasciolopsiasis: A trematode (fluke) infection caused by Fasciolopsis buski, which affects the small intestine and liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
8. Paragonimiasis: A trematode (lung fluke) infection caused by Paragonimus spp., which can affect the lungs, brain, and other organs, including the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
9. Clonorchiasis: A trematode (liver fluke) infection caused by Clonorchis sinensis, which affects the bile ducts and liver. The parasites lay eggs in the bile ducts, causing inflammation, cholangitis, and cholangiocarcinoma.
10. Opisthorchiasis: A trematode (liver fluke) infection caused by Opisthorchis spp., which affects the bile ducts and liver. The parasites lay eggs in the bile ducts, causing inflammation, cholangitis, and cholangiocarcinoma.
11. Heterophyiasis: A trematode (intestinal fluke) infection caused by Heterophyes spp., which affects the small intestine and liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
12. Metagonimiasis: A trematode (intestinal fluke) infection caused by Metagonimus spp., which affects the small intestine and liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
13. Echinostomiasis: A trematode (intestinal fluke) infection caused by Echinostoma spp., which affects the small intestine and liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
14. Gastrodiscoidiasis: A trematode (intestinal fluke) infection caused by Gastrodiscoides spp., which affects the large intestine and liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
15. Fascioliasis: A trematode (liver fluke) infection caused by Fasciola spp., which affects the liver and bile ducts. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
16. Paragonimiasis: A trematode (lung fluke) infection caused by Paragonimus spp., which affects the lungs and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
17. Schistosomiasis: A trematode (blood fluke) infection caused by Schistosoma spp., which affects the blood vessels and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
18. Clonorchiasis: A trematode (liver fluke) infection caused by Clonorchis sinensis, which affects the liver and bile ducts. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
19. Opisthorchiasis: A trematode (liver fluke) infection caused by Opisthorchis spp., which affects the liver and bile ducts. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
20. Metagonimiasis: A trematode (intestinal fluke) infection caused by Metagonimus spp., which affects the small intestine and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
21. Heterophyesiasis: A trematode (intestinal fluke) infection caused by Heterophyes spp., which affects the small intestine and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
22. Echinostomiasis: A trematode (intestinal fluke) infection caused by Echinostoma spp., which affects the small intestine and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
23. Fasciolopsiasis: A trematode (intestinal fluke) infection caused by Fasciolopsis buski, which affects the small intestine and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
24. Paragonimiasis: A trematode (lung fluke) infection caused by Paragonimus spp., which affects the lungs and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
25. Spirometra mansoni: A trematode (tapeworm) infection caused by Spirometra mansoni, which affects the brain and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
26. Taenia solium: A trematode (tapeworm) infection caused by Taenia solium, which affects the brain and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
27. Hymenolepis nana: A trematode (tapeworm) infection caused by Hymenolepis nana, which affects the small intestine and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
28. Diphyllobothrium latum: A trematode (tapeworm) infection caused by Diphyllobothrium latum, which affects the small intestine and sometimes the liver. The larvae migrate through the liver tissue, causing inflammation, necrosis, and fibrosis.
29. Echinococcus granulosus:

Retinal vein occlusion (RVO) is a medical condition that occurs when one of the retinal veins, which drains blood from the retina, becomes blocked by a blood clot or atherosclerotic plaque. This blockage can cause hemorrhages, fluid accumulation, and damage to the retinal tissue, leading to vision loss.

There are two types of RVO: branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). BRVO affects a smaller branch retinal vein, while CRVO affects the main retinal vein. CRVO is generally associated with more severe vision loss than BRVO.

Risk factors for RVO include hypertension, diabetes, high cholesterol levels, smoking, and glaucoma. Age is also a significant risk factor, as RVO becomes more common with increasing age. Treatment options for RVO may include controlling underlying medical conditions, laser therapy, intravitreal injections of anti-VEGF agents or steroids, and surgery in some cases.

Chemoembolization, therapeutic is a medical procedure that involves the delivery of chemotherapy drugs directly to a tumor through its blood supply, followed by the blocking of the blood vessel leading to the tumor. This approach allows for a higher concentration of the chemotherapy drug to be delivered directly to the tumor while minimizing exposure to the rest of the body. The embolization component of the procedure involves blocking the blood vessel with various substances such as microspheres, gel foam, or coils, which can help to starve the tumor of oxygen and nutrients.

Therapeutic chemoembolization is typically used in the treatment of liver cancer, including primary liver cancer (hepatocellular carcinoma) and metastatic liver cancer. It may also be used in other types of cancer that have spread to the liver. The procedure can help to reduce the size of the tumor, relieve symptoms, and improve survival rates in some patients. However, like all medical procedures, it carries a risk of complications such as infection, bleeding, and damage to surrounding tissues.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

Pathological constriction refers to an abnormal narrowing or tightening of a body passage or organ, which can interfere with the normal flow of blood, air, or other substances through the area. This constriction can occur due to various reasons such as inflammation, scarring, or abnormal growths, and can affect different parts of the body, including blood vessels, airways, intestines, and ureters. Pathological constriction can lead to a range of symptoms and complications depending on its location and severity, and may require medical intervention to correct.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

Bile ducts are tubular structures that carry bile from the liver to the gallbladder for storage or directly to the small intestine to aid in digestion. There are two types of bile ducts: intrahepatic and extrahepatic. Intrahepatic bile ducts are located within the liver and drain bile from liver cells, while extrahepatic bile ducts are outside the liver and include the common hepatic duct, cystic duct, and common bile duct. These ducts can become obstructed or inflamed, leading to various medical conditions such as cholestasis, cholecystitis, and gallstones.

Experimental liver cirrhosis refers to a controlled research setting where various factors and substances are intentionally introduced to induce liver cirrhosis in animals or cell cultures. The purpose is to study the mechanisms, progression, potential treatments, and prevention strategies for liver cirrhosis. This could involve administering chemicals, drugs, alcohol, viruses, or manipulating genes associated with liver damage and fibrosis. It's important to note that results from experimental models may not directly translate to human conditions, but they can provide valuable insights into disease pathophysiology and therapeutic development.

Hepatic encephalopathy (HE) is a neuropsychiatric syndrome associated with liver dysfunction and/or portosystemic shunting. It results from the accumulation of toxic substances, such as ammonia and inflammatory mediators, which are normally metabolized by the liver. HE can present with a wide range of symptoms, including changes in sleep-wake cycle, altered mental status, confusion, disorientation, asterixis (flapping tremor), and in severe cases, coma. The diagnosis is based on clinical evaluation, neuropsychological testing, and exclusion of other causes of cognitive impairment. Treatment typically involves addressing the underlying liver dysfunction, reducing ammonia production through dietary modifications and medications, and preventing further episodes with lactulose or rifaximin therapy.

Postoperative complications refer to any unfavorable condition or event that occurs during the recovery period after a surgical procedure. These complications can vary in severity and may include, but are not limited to:

1. Infection: This can occur at the site of the incision or inside the body, such as pneumonia or urinary tract infection.
2. Bleeding: Excessive bleeding (hemorrhage) can lead to a drop in blood pressure and may require further surgical intervention.
3. Blood clots: These can form in the deep veins of the legs (deep vein thrombosis) and can potentially travel to the lungs (pulmonary embolism).
4. Wound dehiscence: This is when the surgical wound opens up, which can lead to infection and further complications.
5. Pulmonary issues: These include atelectasis (collapsed lung), pneumonia, or respiratory failure.
6. Cardiovascular problems: These include abnormal heart rhythms (arrhythmias), heart attack, or stroke.
7. Renal failure: This can occur due to various reasons such as dehydration, blood loss, or the use of certain medications.
8. Pain management issues: Inadequate pain control can lead to increased stress, anxiety, and decreased mobility.
9. Nausea and vomiting: These can be caused by anesthesia, opioid pain medication, or other factors.
10. Delirium: This is a state of confusion and disorientation that can occur in the elderly or those with certain medical conditions.

Prompt identification and management of these complications are crucial to ensure the best possible outcome for the patient.

Liver regeneration is the ability of the liver to restore its original mass and function after injury or surgical resection. This complex process involves the proliferation and differentiation of mature hepatocytes, as well as the activation and transdifferentiation of various types of stem and progenitor cells located in the liver. The mechanisms that regulate liver regeneration include a variety of growth factors, hormones, and cytokines, which act in a coordinated manner to ensure the restoration of normal liver architecture and function. Liver regeneration is essential for the survival of individuals who have undergone partial hepatectomy or who have suffered liver damage due to various causes, such as viral hepatitis, alcohol abuse, or drug-induced liver injury.

Liver function tests (LFTs) are a group of blood tests that are used to assess the functioning and health of the liver. These tests measure the levels of various enzymes, proteins, and waste products that are produced or metabolized by the liver. Some common LFTs include:

1. Alanine aminotransferase (ALT): An enzyme found primarily in the liver, ALT is released into the bloodstream in response to liver cell damage. Elevated levels of ALT may indicate liver injury or disease.
2. Aspartate aminotransferase (AST): Another enzyme found in various tissues, including the liver, heart, and muscles. Like ALT, AST is released into the bloodstream following tissue damage. High AST levels can be a sign of liver damage or other medical conditions.
3. Alkaline phosphatase (ALP): An enzyme found in several organs, including the liver, bile ducts, and bones. Elevated ALP levels may indicate a blockage in the bile ducts, liver disease, or bone disorders.
4. Gamma-glutamyl transferase (GGT): An enzyme found mainly in the liver, pancreas, and biliary system. Increased GGT levels can suggest liver disease, alcohol consumption, or the use of certain medications.
5. Bilirubin: A yellowish pigment produced when hemoglobin from red blood cells is broken down. Bilirubin is processed by the liver and excreted through bile. High bilirubin levels can indicate liver dysfunction, bile duct obstruction, or certain types of anemia.
6. Albumin: A protein produced by the liver that helps maintain fluid balance in the body and transports various substances in the blood. Low albumin levels may suggest liver damage, malnutrition, or kidney disease.
7. Total protein: A measure of all proteins present in the blood, including albumin and other types of proteins produced by the liver. Decreased total protein levels can indicate liver dysfunction or other medical conditions.

These tests are often ordered together as part of a routine health checkup or when evaluating symptoms related to liver function or disease. The results should be interpreted in conjunction with clinical findings, medical history, and other diagnostic tests.

Ascites is an abnormal accumulation of fluid in the peritoneal cavity, which is the space between the lining of the abdominal wall and the organs within it. This buildup of fluid can cause the belly to swell and become distended. Ascites can be caused by various medical conditions, including liver cirrhosis, cancer, heart failure, and kidney disease. The accumulation of fluid in the peritoneal cavity can lead to complications such as infection, reduced mobility, and difficulty breathing. Treatment for ascites depends on the underlying cause and may include diuretics, paracentesis (a procedure to remove excess fluid from the abdomen), or treatment of the underlying medical condition.

Alcoholic Liver Cirrhosis is a medical condition characterized by irreversible scarring (fibrosis) and damage to the liver caused by excessive consumption of alcohol over an extended period. The liver's normal structure and function are progressively impaired as healthy liver tissue is replaced by scarred tissue, leading to the formation of nodules (regenerative noduli).

The condition typically develops after years of heavy drinking, with a higher risk for those who consume more than 60 grams of pure alcohol daily. The damage caused by alcoholic liver cirrhosis can be life-threatening and may result in complications such as:

1. Ascites (accumulation of fluid in the abdomen)
2. Encephalopathy (neurological dysfunction due to liver failure)
3. Esophageal varices (dilated veins in the esophagus that can rupture and bleed)
4. Hepatorenal syndrome (kidney failure caused by liver disease)
5. Increased susceptibility to infections
6. Liver cancer (hepatocellular carcinoma)
7. Portal hypertension (increased blood pressure in the portal vein that supplies blood to the liver)

Abstaining from alcohol and managing underlying medical conditions are crucial for slowing down or halting disease progression. Treatment may involve medications, dietary changes, and supportive care to address complications. In severe cases, a liver transplant might be necessary.

Blood flow velocity is the speed at which blood travels through a specific part of the vascular system. It is typically measured in units of distance per time, such as centimeters per second (cm/s) or meters per second (m/s). Blood flow velocity can be affected by various factors, including cardiac output, vessel diameter, and viscosity of the blood. Measuring blood flow velocity is important in diagnosing and monitoring various medical conditions, such as heart disease, stroke, and peripheral vascular disease.

Retrospective studies, also known as retrospective research or looking back studies, are a type of observational study that examines data from the past to draw conclusions about possible causal relationships between risk factors and outcomes. In these studies, researchers analyze existing records, medical charts, or previously collected data to test a hypothesis or answer a specific research question.

Retrospective studies can be useful for generating hypotheses and identifying trends, but they have limitations compared to prospective studies, which follow participants forward in time from exposure to outcome. Retrospective studies are subject to biases such as recall bias, selection bias, and information bias, which can affect the validity of the results. Therefore, retrospective studies should be interpreted with caution and used primarily to generate hypotheses for further testing in prospective studies.

Splenomegaly is a medical term that refers to an enlargement or expansion of the spleen beyond its normal size. The spleen is a vital organ located in the upper left quadrant of the abdomen, behind the stomach and below the diaphragm. It plays a crucial role in filtering the blood, fighting infections, and storing red and white blood cells and platelets.

Splenomegaly can occur due to various underlying medical conditions, including infections, liver diseases, blood disorders, cancer, and inflammatory diseases. The enlarged spleen may put pressure on surrounding organs, causing discomfort or pain in the abdomen, and it may also lead to a decrease in red and white blood cells and platelets, increasing the risk of anemia, infections, and bleeding.

The diagnosis of splenomegaly typically involves a physical examination, medical history, and imaging tests such as ultrasound, CT scan, or MRI. Treatment depends on the underlying cause and may include medications, surgery, or other interventions to manage the underlying condition.

Sclerotherapy is a medical procedure used to treat varicose veins and spider veins. It involves the injection of a solution (called a sclerosant) directly into the affected vein, which causes the vein to collapse and eventually fade away. The sclerosant works by irritating the lining of the vein, causing it to swell and stick together, which then leads to clotting and the eventual reabsorption of the vein by the body.

The procedure is typically performed in a doctor's office or outpatient setting and may require multiple sessions depending on the severity and number of veins being treated. Common side effects include bruising, swelling, and discomfort at the injection site, as well as the possibility of developing brownish pigmentation or small ulcers near the treatment area. However, these side effects are usually temporary and resolve on their own within a few weeks.

Sclerotherapy is considered a safe and effective treatment for varicose veins and spider veins, with high success rates and low complication rates. It is important to note that while sclerotherapy can improve the appearance of affected veins, it does not prevent new veins from developing in the future.

Muscle contraction is the physiological process in which muscle fibers shorten and generate force, leading to movement or stability of a body part. This process involves the sliding filament theory where thick and thin filaments within the sarcomeres (the functional units of muscles) slide past each other, facilitated by the interaction between myosin heads and actin filaments. The energy required for this action is provided by the hydrolysis of adenosine triphosphate (ATP). Muscle contractions can be voluntary or involuntary, and they play a crucial role in various bodily functions such as locomotion, circulation, respiration, and posture maintenance.

... the portal vein is formed by the union of the superior mesenteric vein and the splenic vein. For this reason, the portal vein ... Accessory hepatic portal veins are those veins that drain directly into the liver without joining the hepatic portal vein. ... splenic veins, inferior mesenteric, left, right gastric veins and the pancreatic vein. Conditions involving the portal vein ... Unlike most veins, the portal vein does not drain into the heart. Rather, it is part of a portal venous system that delivers ...
The procedure involves injecting the right or left portal vein with embolic material to occlude portal blood flow. By occluding ... Portal vein thrombosis, liver infarction, necrosis and portal hypertension. Risks related to any percutaneous transhepatic ... Additionally, complete lobar portal vein occlusion of either lobe would preclude expected increases in FLR from PVE due to ... Though rare, the left portal vein may be embolized prior to a left-sided resection. The increase in FLR is a result of cellular ...
... (PVT) is a vascular disease of the liver that occurs when a blood clot occurs in the hepatic portal vein ... The diagnosis of portal vein thrombosis is usually made with imaging confirming a clot in the portal vein; ultrasound is the ... The main portal vein is formed by the union of the splenic vein and superior mesenteric vein (SMV). It is responsible for ... Type 1 is limited to the main portal vein, Type 2 involves only a portal vein branch (2a, or 2b if both branches are affected ...
The main risk factor for SVT in the lower limbs is varicose veins. The portal vein also known as the hepatic portal vein ... The deep veins of the lower limb include the common femoral vein, femoral vein, and the deep femoral vein; the popliteal vein, ... the middle cardiac vein, the small cardiac vein, the smallest cardiac veins, and the anterior cardiac veins. Cardiac veins ... Small, medium, and large veins The small veins merge to feed as tributaries into medium-sized veins. The medium veins feed into ...
The right gastric vein (pyloric vein) drains blood from the lesser curvature of the stomach into the hepatic portal vein. It is ... Once there, it joins onto the portal vein before the duodenum. The prepyloric vein is the last connecting branch onto the right ... The right gastric vein drains deoxygenated blood from the lesser curvature of the stomach. Left gastric vein Chiva, Luis M.; ... portalvein) (Anatomy NAV infobox with use of other NAV parameters, Articles with TA98 identifiers, Veins of the torso, Stomach) ...
... azygos vein).[citation needed] The esophageal branch of the left gastric vein drains into the azygos vein. In cases of portal ... It drains into the portal vein near the superior border of the pancreas. The left gastric vein drains deoxygenated blood from ... The left gastric vein (or coronary vein) is a vein that derives from tributaries draining the lesser curvature of the stomach. ... It also acts as collaterals between the portal vein and the systemic venous system of the lower esophagus ( ...
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... of the hepatic portal vein. Cystic veins do not accompany the cystic artery. Those cystic veins that arise upon the superior ... The rest of the gallbladder drains into 1-2 small cystic veins which then usually empty into either the hepatic portal vein ... The cystic veins (usually multiple small veins rather than a single cystic vein) drain venous blood from the gallbladder and ... one or more cystic vein(s) drain(s) into the right branch of the hepatic portal vein directly. Standring, Susan (2020). Gray's ...
The splenic vein then merges with the superior mesenteric vein to form the portal vein. Tributaries of the inferior mesenteric ... It usually terminates when reaching the splenic vein, which goes on to form the portal vein with the superior mesenteric vein ( ... These include: left colic vein sigmoid veins superior rectal vein rectosigmoid veins Anatomical variations include the inferior ... mesenteric vein draining into the confluence of the superior mesenteric vein and splenic vein and the inferior mesenteric vein ...
Volume III The chest and the diaphragm; the lungs; the heart; arteries; veins; the portal vein; the abdomen; the bowels and ...
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The vitelline veins give rise to: Hepatic veins Inferior portion of Inferior vena cava Portal vein Superior mesenteric vein ... forms the trunk of the portal vein. The vitelline veins drain the yolk sac during early embryonic development. They also drain ... The vitelline veins are veins that drain blood from the yolk sac and the gut tube during gestation. They run upward at first in ... and become the branches of the portal vein. The vessels draining the plexus into the sinus venosus are termed the venae ...
portal p. Suppurative inflammation of the portal vein. The disease is characterized by intermittent high temperature with ...
Portal Vein: Patent main portal vein. Gallbladder: No stones, wall thickening, or pericholecystic fluid. Common Bile Duct: ...
The portal vein and its tributaries. Cystic duct.Visceral surface of liver. Standring S, Borley NR, eds. (2008). Gray's anatomy ...
Portal vein thrombosis Thrombosis of the splenic vein Renal vein thrombosis (thrombosis of the veins of the kidneys) Ovarian ... Other rarer forms include retinal vein thrombosis, mesenteric vein thrombosis (affecting veins draining blood from the ... axillary and subclavian veins) Budd-Chiari syndrome (thrombosis of the hepatic vein) Thrombosis of the hepatic portal system, ... thrombosis of the veins of the brain and head Central retinal vein occlusion and branch retinal vein occlusion: despite the ...
Portal vein embolization prior to liver resection. First developed by Sadek Hilal in 1968, embolization is a minimally invasive ... Patients who undergo cerebral embolization or portal vein embolization are usually given a general anesthetic. Access to the ... 2002). "Transhepatic portal vein embolization: anatomy, indications, and technical considerations". Radiographics. 22 (5): 1063 ... sotradecol - This agent is used for superficial lower extremity varicose veins. It has been around for a very long time and is ...
As a tributary of the superior mesenteric vein, it is a part of the hepatic portal system. This article incorporates text in ... The right gastroepiploic vein (right gastroomental vein) is a blood vessel that drains blood from the greater curvature and ... Veins of the torso, Stomach, All stub articles, Cardiovascular system stubs). ... left part of the body of the stomach into the superior mesenteric vein. It runs from left to right along the greater curvature ...
The portal vein is the site where hypertension (high blood pressure) can produce a myriad of deleterious effects throughout the ... Veins have one-way valves that help blood flow toward the heart. If the valves are weak or damaged, blood can pool in veins, ... Y-90 video demonstration: SIR-Spheres Y-90 resin microspheres Mode of Action Video Portal vein embolization (PVE): delivery of ... May, Benjamin J.; Madoff, David C. (June 2012). "Portal vein embolization: rationale, technique, and current application". ...
An increased portal vein pulsatility may be seen. However, this may be a sign of elevated right atrial pressure. Portal vein ... The AGA does not recommend in routine screening for portal vein thrombosis. If there is a portal vein thrombosis, the AGA ... Blood from the portal venous system may be forced through the paraumbilical veins and ultimately to the abdominal wall veins. ... Goncalvesova E, Varga I, Tavacova M, Lesny P (2013). "Changes of portal vein flow in heart failure patients with liver ...
Later, Stephanie works on Meredith's portal vein trial. Stephanie sides with Alex Karev (Justin Chambers) in surgery over ...
This is done with the intent of inducing growth in the contralateral hepatic lobe, not dissimilarly from portal vein ... Most authors report a comparable future liver remnant hypertrophy between portal vein embolization and RL, ranging between 10 ... Madoff, David C.; Vauthey, Jean-Nicolas (2013-06-01). "Re: Portal Vein Embolization: What Do We Know?". CardioVascular and ... "Portal vein embolization stimulates tumour growth in patients with colorectal cancer liver metastases". HPB. 14 (7): 461-468. ...
Redford ML, Ellis R, Rees CJ (2005). "Fusobacterium necrophorum infection associated with portal vein thrombosis". J Med ... Other complications from F. necrophorum include meningitis, complicated by thrombosis of the internal jugular vein, thrombosis ... Type strain of Fusobacterium necrophorum at BacDive - the Bacterial Diversity Metadatabase Portal: Biology (Articles with short ... of the cerebral veins, and infection of the urogenital and the gastrointestinal tracts. Although this infection is rare, ...
Portal vein embolization (PVE): delivery of embolic material into the portal vein feeding the lobe of liver containing the ... Cancer Treatment Center of America, Intra-Arterial chemotherapy May, Benjamin J.; Madoff, David C. (June 2012). "Portal vein ... portal vein embolization, transarterial/bland embolization, or image guided ablation (RFA, MWA, IRE, Cryoablation). Lung cancer ...
The splenic vein ends in the portal vein, formed when the splenic vein joins the superior mesenteric vein. The splenic vein can ... via the inferior mesenteric vein, which drains in the splenic vein shortly before the origin of the hepatic portal vein. ... of portal vein thrombosis and portal hypertension but localized to part of the territory drained by the splenic vein. These ... It is part of the hepatic portal system. The splenic vein is formed from small venules that leave the spleen. It travels above ...
Cerebral vein thrombosis. Portal vein thrombosis, hepatic vein, or other intra-abdominal thrombotic events. Jugular vein ... blood clots develop in the deep veins of the lower extremities, deep vein thrombosis (DVT) or as a blood clot in the lung, ... Central retinal vein and/or central retinal arterial thrombosis. Small vessel thrombosis affecting one or more organs, systems ... The initial symptoms of TS present similarly to the symptoms experienced in deep vein thrombosis. Symptoms of a DVT may include ...
"Total Anomalous Pulmonary Venous Drainage Into the Portal Vein." American Heart Journal. vol. 53, no. 4, 1957, pp. 616-623. ...
"Control of bleeding from the portal/superior mesenteric vein. Operative Techniques in General Surgery 2007 Dec;(9)4:152-159 ...

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