The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.
The ratio of alveolar ventilation to simultaneous alveolar capillary blood flow in any part of the lung. (Stedman, 25th ed)
Elements that constitute group 18 (formerly the zero group) of the periodic table. They are gases that generally do not react chemically.
Measurement of oxygen and carbon dioxide in the blood.
Irregular HEART RATE caused by abnormal function of the SINOATRIAL NODE. It is characterized by a greater than 10% change between the maximum and the minimum sinus cycle length or 120 milliseconds.
An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
The circulation of the BLOOD through the LUNGS.
The amount of a gas taken up, by the pulmonary capillary blood from the alveolar gas, per minute per unit of average pressure of the gradient of the gas across the BLOOD-AIR BARRIER.
The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.
The pressure that would be exerted by one component of a mixture of gases if it were present alone in a container. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
That part of the RESPIRATORY TRACT or the air within the respiratory tract that does not exchange OXYGEN and CARBON DIOXIDE with pulmonary capillary blood.
The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)
The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).
The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)
The volume of air inspired or expired during each normal, quiet respiratory cycle. Common abbreviations are TV or V with subscript T.
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.
Pulmonary injury following the breathing in of toxic smoke from burning materials such as plastics, synthetics, building materials, etc. This injury is the most frequent cause of death in burn patients.
Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.
Excessive accumulation of extravascular fluid in the lung, an indication of a serious underlying disease or disorder. Pulmonary edema prevents efficient PULMONARY GAS EXCHANGE in the PULMONARY ALVEOLI, and can be life-threatening.
Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.
A syndrome characterized by the clinical triad of advanced chronic liver disease, pulmonary vascular dilatations, and reduced arterial oxygenation (HYPOXEMIA) in the absence of intrinsic cardiopulmonary disease. This syndrome is common in the patients with LIVER CIRRHOSIS or portal hypertension (HYPERTENSION, PORTAL).
A pulmonary ventilation rate faster than is metabolically necessary for the exchange of gases. It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide.
Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2).
Water content outside of the lung vasculature. About 80% of a normal lung is made up of water, including intracellular, interstitial, and blood water. Failure to maintain the normal homeostatic fluid exchange between the vascular space and the interstitium of the lungs can result in PULMONARY EDEMA and flooding of the alveolar space.
The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).
Controlled physical activity which is performed in order to allow assessment of physiological functions, particularly cardiovascular and pulmonary, but also aerobic capacity. Maximal (most intense) exercise is usually required but submaximal exercise is also used.
Relatively complete absence of oxygen in one or more tissues.
The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.
A syndrome characterized by progressive life-threatening RESPIRATORY INSUFFICIENCY in the absence of known LUNG DISEASES, usually following a systemic insult such as surgery or major TRAUMA.
Physical activity which is usually regular and done with the intention of improving or maintaining PHYSICAL FITNESS or HEALTH. Contrast with PHYSICAL EXERTION which is concerned largely with the physiologic and metabolic response to energy expenditure.
The use of a bicycle for transportation or recreation. It does not include the use of a bicycle in studying the body's response to physical exertion (BICYCLE ERGOMETRY TEST see EXERCISE TEST).
Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.
Pathological processes involving any part of the LUNG.
The volume of air that is exhaled by a maximal expiration following a maximal inspiration.
Measurement of volume of air inhaled or exhaled by the lung.
The number of times the HEART VENTRICLES contract per unit of time, usually per minute.
The processes of diffusion across the BLOOD-AIR BARRIER, and the chemical reactions coupled with diffusion that effect the rate of PULMONARY GAS EXCHANGE, generally at the alveolar level.
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)
A normal intermediate in the fermentation (oxidation, metabolism) of sugar. The concentrated form is used internally to prevent gastrointestinal fermentation. (From Stedman, 26th ed)
Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.
Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.
Neon. A noble gas with the atomic symbol Ne, atomic number 10, and atomic weight 20.18. It is found in the earth's crust and atmosphere as an inert, odorless gas and is used in vacuum tubes and incandescent lamps.
A method of mechanical ventilation in which pressure is maintained to increase the volume of gas remaining in the lungs at the end of expiration, thus reducing the shunting of blood through the lungs and improving gas exchange.
Elements of limited time intervals, contributing to particular results or situations.
The act of BREATHING in.
Loss of water by diffusion through the skin and by evaporation from the respiratory tract.
The loss of water vapor by plants to the atmosphere. It occurs mainly from the leaves through pores (stomata) whose primary function is gas exchange. The water is replaced by a continuous column of water moving upwards from the roots within the xylem vessels. (Concise Dictionary of Biology, 1990)
Artificial respiration (RESPIRATION, ARTIFICIAL) using an oxygenated fluid.

Acute saline infusion reduces alveolar-capillary membrane conductance and increases airflow obstruction in patients with left ventricular dysfunction. (1/1644)

BACKGROUND: Impaired alveolar-capillary membrane conductance is the major cause for the reduction in pulmonary diffusing capacity for carbon monoxide (DLCO) in heart failure. Whether this reduction is fixed, reflecting pulmonary microvascular damage, or is variable is unknown. The aim of this study was to assess whether DLCO and its subdivisions, alveolar-capillary membrane conductance (DM) and pulmonary capillary blood volume (Vc), were sensitive to changes in intravascular volume. In addition, we examined the effects of volume loading on airflow rates. METHODS AND RESULTS: Ten patients with left ventricular dysfunction (LVD) and 8 healthy volunteers were studied. DM and Vc were determined by the Roughton and Forster method. The forced expiratory volume in 1 second (FEV1), vital capacity, and peak expiratory flow rates (PEFR) were also recorded. In patients with LVD, infusion of 10 mL. kg-1 body wt of 0.9% saline acutely reduced DM (12.0+/-3.3 versus 10.4+/-3.5 mmol. min-1. kPa-1, P<0.005), FEV1 (2.3+/-0.4 versus 2.1+/-0.4 L, P<0.0005), and PEFR (446+/-55 versus 414+/-56 L. min-1, P<0.005). All pulmonary function tests had returned to baseline values 24 hours later. In normal subjects, saline infusion had no measurable effect on lung function. CONCLUSIONS: Acute intravascular volume expansion impairs alveolar-capillary membrane function and increases airflow obstruction in patients with LVD but not in normal subjects. Thus, the abnormalities of pulmonary diffusion in heart failure, which were believed to be fixed, also have a variable component that could be amenable to therapeutic intervention.  (+info)

Peripheral muscle ergoreceptors and ventilatory response during exercise recovery in heart failure. (2/1644)

Recent studies have suggested that the increased ventilatory response during exercise in patients with chronic heart failure was related to the activation of muscle metaboreceptors. To address this issue, 23 patients with heart failure and 7 normal subjects performed arm and leg bicycle exercises with and without cuff inflation around the arms or the thighs during recovery. Obstruction slightly reduced ventilation and gas exchange variables at recovery but did not change the kinetics of recovery of these parameters compared with nonobstructed recovery: half-time of ventilation recovery was 175 +/- 54 to 176 +/- 40 s in patients and 155 +/- 66 to 127 +/- 13 s in controls (P < 0.05, patients vs. controls, not significant within each group from baseline to obstructed recovery). We conclude that muscle metaboreceptor activation does not seem to play a role in the exertion hyperventilation of patients with heart failure.  (+info)

Continuous arterial P(O2) and P(CO2) measurements in swine during nitrous oxide and xenon elimination: prevention of diffusion hypoxia. (3/1644)

BACKGROUND: During nitrous oxide (N2O) elimination, arterial oxygen tension (PaO2) decreases because of the phenomenon commonly called diffusive hypoxia. The authors questioned whether similar effects occur during xenon elimination. METHODS: Nineteen anesthetized and paralyzed pigs were mechanically ventilated randomly for 30 min using inspiratory gas mixtures of 30% oxygen and either 70% N2O or xenon. The inspiratory gas was replaced by a mixture of 70% nitrogen and 30% oxygen. PaO2 and carbon dioxide tensions were recorded continuously using an indwelling arterial sensor. RESULTS: The PaO2 decreased from 119+/-10 mm Hg to 102+/-12 mm Hg (mean+/-SD) during N2O washout (P<0.01) and from 116+/-9 mm Hg to 110+/-8 mm Hg during xenon elimination (P<0.01), with a significant difference (P<0.01) between baseline and minimum PaO2 values (deltaPaO2, 17+/-6 mm Hg during N2O washout and 6+/-3 mm Hg during xenon washout). The PaCO2 value also decreased (from 39.3+/-6.3 mm Hg to 37.6+/-5.8 mm Hg) during N2O washout (P<0.01) and during xenon elimination (from 35.4+/-1.6 mm Hg to 34.9+/-1.6 mm Hg; P< 0.01). The deltaPaCO2 was 1.7+/-0.9 mm Hg in the N2O group and 0.5+/-0.3 mm Hg in the xenon group (P<0.01). CONCLUSION: Diffusive hypoxia is unlikely to occur during recovery from xenon anesthesia, probably because of the low blood solubility of this gas.  (+info)

Breathing patterns during slow and fast ramp exercise in man. (4/1644)

Breathing frequency (fb), tidal volume (VT), and respiratory timing during slow (SR, 8 W min-1) and fast (FR, 65 W min-1) ramp exercise to exhaustion on a cycle ergometer was examined in seven healthy male subjects. Expiratory ventilation (VE), pulmonary gas exchange (VO2 and VCO2) and end-tidal gas tensions (PET,O2 and PET,CO2) were determined using breath-by-breath techniques. Arterialized venous blood was sampled from a dorsal hand vein at 2 min intervals during SR and 30 s intervals during FR and analysed for arterial plasma PCO2 (PaCO2). PET,CO2 increased with increasing work rates (WRs) below the ventilatory threshold (VT); at WRs > or = 90% VO2,max, PET,CO2 was reduced (P < 0.05) below 0 W values in SR but not in FR.fb and VT were similar for SR and FR at all submaximal WRs, resulting in a similar VE. At exhaustion VE was similar but fb was higher (P < 0.05) and VT was lower (P < 0.05) in SR (fb, 51 +/- 10 breaths min-1; VT, 2590 +/- 590 ml) than in FR (fb, 42 +/- 8 breaths min-1; VT, 3050 +/- 470 ml). The time of expiration (TE) decreased with increasing WR, but there was no difference between SR and FR. The time of inspiration (TI) decreased at exercise intensities > or = VT; at exhaustion, TI was shorter (P < 0.05) during SR (0.512 +/- 0.097 s) than during FR (0.753 +/- 0.100 s). The TI to total breath duration (TI/TTot) and the inspiratory flow (VT/TI) were similar during SR and FR at all submaximal exercise intensities; at VO2,max, TI/TTot was lower (P < 0.05) and VT/TI was higher (P < 0.05) during SR (TI/TTot, 0.473 +/- 0.030; VT/TI, 5.092 +/- 0.377 l s-1) than during FR (TI/TTot, 0.567 +/- 0.050; VT/TI, 4.117 +/- 0.635 l s-1). These results suggest that during progressive exercise, breathing pattern and respiratory timing may be determined, at least at submaximal work rates, independently of alveolar and arterial PCO2.  (+info)

Airway closure, atelectasis and gas exchange during general anaesthesia. (5/1644)

Airway closure and the formation of atelectasis have been proposed as important contributors to impairment of gas exchange during general anaesthesia. We have elucidated the relationships between each of these two mechanisms and gas exchange. We studied 35 adults with healthy lungs, undergoing elective surgery. Airway closure was measured using the foreign gas bolus technique, atelectasis was estimated by analysis of computed x-ray tomography, and ventilation-perfusion distribution (VA/Q) was assessed by the multiple inert gas elimination technique. The difference between closing volume and expiratory reserve volume (CV-ERV) increased from the awake to the anaesthetized state. Linear correlations were found between atelectasis and shunt (r = 0.68, P < 0.001), and between CV-ERV and the amount of perfusion to poorly ventilated lung units ("low Va/Q", r = 0.57, P = 0.001). Taken together, the amount of atelectasis and airway closure may explain 75% of the deterioration in PaO2. There was no significant correlation between CV-ERV and atelectasis. We conclude that in anaesthetized adults with healthy lungs, undergoing mechanical ventilation, both airway closure and atelectasis contributed to impairment of gas exchange. Atelectasis and airway closure do not seem to be closely related.  (+info)

Cardiopulmonary resuscitation: effect of CPAP on gas exchange during chest compressions. (6/1644)

BACKGROUND: Conventional cardiopulmonary resuscitation (CPR) includes 80-100/min precordial compressions with intermittent positive pressure ventilation (IPPV) after every fifth compression. To prevent gastric insufflation, chest compressions are held during IPPV if the patient is not intubated. Elimination of IPPV would simplify CPR and might offer physiologic advantages, but compression-induced ventilation without IPPV has been shown to result in hypercapnia. The authors hypothesized that application of continuous positive airway pressure (CPAP) might increase CO2 elimination during chest compressions. METHODS: After appropriate instrumentation and measurement of baseline data, ventricular fibrillation was induced in 18 pigs. Conventional CPR was performed as a control (CPR(C)) for 5 min. Pauses were then discontinued, and animals were assigned randomly to receive alternate trials of uninterrupted chest compressions at a rate of 80/min without IPPV, either at atmospheric airway pressure (CPR(ATM)) or with CPAP (CPR(CPAP)). CPAP was adjusted to produce a minute ventilation of 75% of the animal's baseline ventilation. Data were summarized as mean +/- SD and compared with Student t test for paired observations. RESULTS: During CPR without IPPV, CPAP decreased PaCO2 (55+/-28 vs. 100+/-16 mmHg) and increased SaO2 (0.86+/-0.19 vs. 0.50+/-0.18%; P < 0.001). CPAP also increased arteriovenous oxygen content difference (10.7+/-3.1 vs. 5.5+/-2.3 ml/dl blood) and CO2 elimination (120+/-20 vs. 12+/-20 ml/min; P < 0.01). Differences between CPR(CPAP) and CPR(ATM) in aortic blood pressure, cardiac output, and stroke volume were not significant. CONCLUSIONS: Mechanical ventilation may not be necessary during CPR as long as CPAP is applied. Discontinuation of IPPV will simplify CPR and may offer physiologic advantage.  (+info)

Hemodynamic effects of bilevel nasal positive airway pressure ventilation in patients with heart failure. (7/1644)

AIMS: Benefits of nasal continuous positive airway pressure (CPAP) in patients presenting with chronic heart failure (CHF) are controversial. The purpose of this study was to compare the hemodynamic effects of CPAP and bilevel positive airway pressure (BiPAP) in patients with or without CHF. METHODS AND RESULTS: Twenty patients with CHF and 7 with normal left ventricular function underwent cardiac catheterization. Measurements were made before and after three 20-min periods of BiPAP: expiratory positive airway pressure (EPAP) = 8 cm H2O and inspiratory positive airway pressure (IPAP) = 12 cm H2O, EPAP = 10 cm H2O and IPAP = 15 cm H2O, and CPAP = EPAP = IPAP = 10 cm H2O administered in random order. Positive pressure ventilation decreased cardiac output (CO) and stroke volume. No change was observed in either pulmonary or systemic arterial pressure. There was no difference in the hemodynamic effects of the three ventilation settings. Only mean pulmonary wedge pressure (MPWP) and heart rate were lower with CPAP than with BiPAP. CO decreased only in patients with low MPWP (+info)

A chest wall restrictor to study effects on pulmonary function and exercise. 2. The energetics of restrictive breathing. (8/1644)

Chest wall restriction, whether caused by disease or mechanical constraints such as protective outerwear, can cause decrements in pulmonary function and exercise capacity. However, the study of the oxygen cost associated with mechanical chest restriction has so far been purely qualitative. The previous paper in this series described a device to impose external chest wall restriction, its effects on forced spirometric volumes, and its test-retest reliability. The purpose of this experiment was to measure the oxygen cost associated with varied levels of external chest wall restriction. Oxygen uptake and electromyogram (EMG) of the external intercostals were recorded during chest restriction in 10 healthy males. Subjects rested for 9 min before undergoing volitional isocapnic hyperpnea for 6 min. Subjects breathed at minute ventilations (V.I) of 30, 60, and 90 liters/min with chest wall loads of 0, 25, 50 and 75 mm Hg applied. Frequency of breathing was set at 15, 30, and 45 breaths per minute with a constant tidal volume (VT) of 2 liters. Oxygen uptake was measured continuously at rest and throughout the hyperventilation bouts, while controlling V.I and VT. Integrated EMG (IEMG) from the 3rd intercostal space was recorded during each minute of rest and hyperventilation. Two-way ANOVA with repeated measures revealed that chest wall loading and hyperpnea significantly increased V.O2 values (p < 0.01). External intercostal IEMG levels were significantly increased (p < 0.05) at higher restrictive load (50 and 75 mm Hg) and at the highest minute ventilation (90 liters/min). These data suggest that there is a significant and quantifiable increase in the oxygen cost associated with external chest wall restriction which is directly related to the level of chest wall restriction.  (+info)

Pulmonary gas exchange is the process by which oxygen (O2) from inhaled air is transferred to the blood, and carbon dioxide (CO2), a waste product of metabolism, is removed from the blood and exhaled. This process occurs in the lungs, primarily in the alveoli, where the thin walls of the alveoli and capillaries allow for the rapid diffusion of gases between them. The partial pressure gradient between the alveolar air and the blood in the pulmonary capillaries drives this diffusion process. Oxygen-rich blood is then transported to the body's tissues, while CO2-rich blood returns to the lungs to be exhaled.

The Ventilation-Perfusion (V/Q) ratio is a measure used in respiratory physiology to describe the relationship between the amount of air that enters the alveoli (ventilation) and the amount of blood that reaches the alveoli to pick up oxygen (perfusion).

In a healthy lung, these two processes are well-matched, meaning that well-ventilated areas of the lung also have good blood flow. This results in a V/Q ratio close to 1.0.

However, certain lung conditions such as emphysema or pulmonary embolism can cause ventilation and perfusion to become mismatched, leading to a V/Q ratio that is either higher (ventilation exceeds perfusion) or lower (perfusion exceeds ventilation) than normal. This mismatch can result in impaired gas exchange and lead to hypoxemia (low oxygen levels in the blood).

The V/Q ratio is often used in clinical settings to assess lung function and diagnose respiratory disorders.

The Noble gases are a group of elements in the periodic table, specifically helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). They are called "noble" because they are very unreactive due to having a full complement of electrons in their outer atomic shell, which makes them stable and non-reactive with other elements. This property also means that they do not form compounds under normal conditions. Noble gases are colorless, odorless, tasteless, and nontoxic gases. They are used in various applications such as lighting, medical imaging, and scientific research.

Blood gas analysis is a medical test that measures the levels of oxygen and carbon dioxide in the blood, as well as the pH level, which indicates the acidity or alkalinity of the blood. This test is often used to evaluate lung function, respiratory disorders, and acid-base balance in the body. It can also be used to monitor the effectiveness of treatments for conditions such as chronic obstructive pulmonary disease (COPD), asthma, and other respiratory illnesses. The analysis is typically performed on a sample of arterial blood, although venous blood may also be used in some cases.

Sinus arrhythmia is a type of heart rhythm disorder (arrhythmia) where the normal rhythm generated by the sinus node in the heart varies in rate or pattern. The sinus node is the natural pacemaker of the heart and usually sets a steady pace for heartbeats. However, in sinus arrhythmia, the heart rate may speed up or slow down abnormally during breathing in (inspiration) or breathing out (expiration).

When the heart rate increases during inspiration, it is called "inspiratory sinus arrhythmia," and when the heart rate decreases during expiration, it is called "expiratory sinus arrhythmia." Most people experience a mild form of inspiratory sinus arrhythmia, which is considered normal, especially in children and young adults.

However, if the variation in heart rate is significant or accompanied by symptoms such as palpitations, dizziness, shortness of breath, or chest discomfort, it may require medical evaluation and treatment. Sinus arrhythmia can be caused by various factors, including lung disease, heart disease, electrolyte imbalances, or the use of certain medications.

Oxygen is a colorless, odorless, tasteless gas that constitutes about 21% of the earth's atmosphere. It is a crucial element for human and most living organisms as it is vital for respiration. Inhaled oxygen enters the lungs and binds to hemoglobin in red blood cells, which carries it to tissues throughout the body where it is used to convert nutrients into energy and carbon dioxide, a waste product that is exhaled.

Medically, supplemental oxygen therapy may be provided to patients with conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, heart failure, or other medical conditions that impair the body's ability to extract sufficient oxygen from the air. Oxygen can be administered through various devices, including nasal cannulas, face masks, and ventilators.

Carbon dioxide (CO2) is a colorless, odorless gas that is naturally present in the Earth's atmosphere. It is a normal byproduct of cellular respiration in humans, animals, and plants, and is also produced through the combustion of fossil fuels such as coal, oil, and natural gas.

In medical terms, carbon dioxide is often used as a respiratory stimulant and to maintain the pH balance of blood. It is also used during certain medical procedures, such as laparoscopic surgery, to insufflate (inflate) the abdominal cavity and create a working space for the surgeon.

Elevated levels of carbon dioxide in the body can lead to respiratory acidosis, a condition characterized by an increased concentration of carbon dioxide in the blood and a decrease in pH. This can occur in conditions such as chronic obstructive pulmonary disease (COPD), asthma, or other lung diseases that impair breathing and gas exchange. Symptoms of respiratory acidosis may include shortness of breath, confusion, headache, and in severe cases, coma or death.

Pulmonary circulation refers to the process of blood flow through the lungs, where blood picks up oxygen and releases carbon dioxide. This is a vital part of the overall circulatory system, which delivers nutrients and oxygen to the body's cells while removing waste products like carbon dioxide.

In pulmonary circulation, deoxygenated blood from the systemic circulation returns to the right atrium of the heart via the superior and inferior vena cava. The blood then moves into the right ventricle through the tricuspid valve and gets pumped into the pulmonary artery when the right ventricle contracts.

The pulmonary artery divides into smaller vessels called arterioles, which further branch into a vast network of tiny capillaries in the lungs. Here, oxygen from the alveoli diffuses into the blood, binding to hemoglobin in red blood cells, while carbon dioxide leaves the blood and is exhaled through the nose or mouth.

The now oxygenated blood collects in venules, which merge to form pulmonary veins. These veins transport the oxygen-rich blood back to the left atrium of the heart, where it enters the systemic circulation once again. This continuous cycle enables the body's cells to receive the necessary oxygen and nutrients for proper functioning while disposing of waste products.

Pulmonary diffusing capacity, also known as pulmonary diffusion capacity, is a measure of the ability of the lungs to transfer gas from the alveoli to the bloodstream. It is often used to assess the severity of lung diseases such as chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis.

The most common measurement of pulmonary diffusing capacity is the diffusing capacity for carbon monoxide (DLCO), which reflects the transfer of carbon monoxide from the alveoli to the red blood cells in the capillaries. The DLCO is measured during a spirometry test, which involves breathing in a small amount of carbon monoxide and then measuring how much of it is exhaled.

A reduced DLCO may indicate a problem with the lung's ability to transfer oxygen to the blood, which can be caused by a variety of factors including damage to the alveoli or capillaries, thickening of the alveolar membrane, or a decrease in the surface area available for gas exchange.

It is important to note that other factors such as hemoglobin concentration, carboxyhemoglobin level, and lung volume can also affect the DLCO value, so these should be taken into account when interpreting the results of a diffusing capacity test.

Respiratory mechanics refers to the biomechanical properties and processes that involve the movement of air through the respiratory system during breathing. It encompasses the mechanical behavior of the lungs, chest wall, and the muscles of respiration, including the diaphragm and intercostal muscles.

Respiratory mechanics includes several key components:

1. **Compliance**: The ability of the lungs and chest wall to expand and recoil during breathing. High compliance means that the structures can easily expand and recoil, while low compliance indicates greater resistance to expansion and recoil.
2. **Resistance**: The opposition to airflow within the respiratory system, primarily due to the friction between the air and the airway walls. Airway resistance is influenced by factors such as airway diameter, length, and the viscosity of the air.
3. **Lung volumes and capacities**: These are the amounts of air present in the lungs during different phases of the breathing cycle. They include tidal volume (the amount of air inspired or expired during normal breathing), inspiratory reserve volume (additional air that can be inspired beyond the tidal volume), expiratory reserve volume (additional air that can be exhaled beyond the tidal volume), and residual volume (the air remaining in the lungs after a forced maximum exhalation).
4. **Work of breathing**: The energy required to overcome the resistance and elastic forces during breathing. This work is primarily performed by the respiratory muscles, which contract to generate negative intrathoracic pressure and expand the chest wall, allowing air to flow into the lungs.
5. **Pressure-volume relationships**: These describe how changes in lung volume are associated with changes in pressure within the respiratory system. Important pressure components include alveolar pressure (the pressure inside the alveoli), pleural pressure (the pressure between the lungs and the chest wall), and transpulmonary pressure (the difference between alveolar and pleural pressures).

Understanding respiratory mechanics is crucial for diagnosing and managing various respiratory disorders, such as chronic obstructive pulmonary disease (COPD), asthma, and restrictive lung diseases.

In the context of medicine, and specifically in physiology and respiratory therapy, partial pressure (P or p) is a measure of the pressure exerted by an individual gas in a mixture of gases. It's commonly used to describe the concentrations of gases in the body, such as oxygen (PO2), carbon dioxide (PCO2), and nitrogen (PN2).

The partial pressure of a specific gas is calculated as the fraction of that gas in the total mixture multiplied by the total pressure of the mixture. This concept is based on Dalton's law, which states that the total pressure exerted by a mixture of gases is equal to the sum of the pressures exerted by each individual gas.

For example, in room air at sea level, the partial pressure of oxygen (PO2) is approximately 160 mmHg (mm of mercury), which represents about 21% of the total barometric pressure (760 mmHg). This concept is crucial for understanding gas exchange in the lungs and how gases move across membranes, such as from alveoli to blood and vice versa.

Respiratory dead space is the portion of each tidal volume (the amount of air that moves in and out of the lungs during normal breathing) that does not participate in gas exchange. It mainly consists of the anatomical dead space, which includes the conducting airways such as the trachea, bronchi, and bronchioles, where no alveoli are present for gas exchange to occur.

Additionally, alveolar dead space can also contribute to respiratory dead space when alveoli are perfused inadequately or not at all due to conditions like pulmonary embolism, lung consolidation, or impaired circulation. In these cases, even though air reaches the alveoli, insufficient blood flow prevents efficient gas exchange from taking place.

The sum of anatomical and alveolar dead space is referred to as physiological dead space. An increased respiratory dead space can lead to ventilation-perfusion mismatch and impaired oxygenation, making it a critical parameter in assessing respiratory function, particularly during mechanical ventilation in critically ill patients.

Oxygen consumption, also known as oxygen uptake, is the amount of oxygen that is consumed or utilized by the body during a specific period of time, usually measured in liters per minute (L/min). It is a common measurement used in exercise physiology and critical care medicine to assess an individual's aerobic metabolism and overall health status.

In clinical settings, oxygen consumption is often measured during cardiopulmonary exercise testing (CPET) to evaluate cardiovascular function, pulmonary function, and exercise capacity in patients with various medical conditions such as heart failure, chronic obstructive pulmonary disease (COPD), and other respiratory or cardiac disorders.

During exercise, oxygen is consumed by the muscles to generate energy through a process called oxidative phosphorylation. The amount of oxygen consumed during exercise can provide important information about an individual's fitness level, exercise capacity, and overall health status. Additionally, measuring oxygen consumption can help healthcare providers assess the effectiveness of treatments and rehabilitation programs in patients with various medical conditions.

Medical Definition of Respiration:

Respiration, in physiology, is the process by which an organism takes in oxygen and gives out carbon dioxide. It's also known as breathing. This process is essential for most forms of life because it provides the necessary oxygen for cellular respiration, where the cells convert biochemical energy from nutrients into adenosine triphosphate (ATP), and releases waste products, primarily carbon dioxide.

In humans and other mammals, respiration is a two-stage process:

1. Breathing (or external respiration): This involves the exchange of gases with the environment. Air enters the lungs through the mouth or nose, then passes through the pharynx, larynx, trachea, and bronchi, finally reaching the alveoli where the actual gas exchange occurs. Oxygen from the inhaled air diffuses into the blood, while carbon dioxide, a waste product of metabolism, diffuses from the blood into the alveoli to be exhaled.

2. Cellular respiration (or internal respiration): This is the process by which cells convert glucose and other nutrients into ATP, water, and carbon dioxide in the presence of oxygen. The carbon dioxide produced during this process then diffuses out of the cells and into the bloodstream to be exhaled during breathing.

In summary, respiration is a vital physiological function that enables organisms to obtain the necessary oxygen for cellular metabolism while eliminating waste products like carbon dioxide.

In medical terms, gases refer to the state of matter that has no fixed shape or volume and expands to fill any container it is placed in. Gases in the body can be normal, such as the oxygen, carbon dioxide, and nitrogen that are present in the lungs and blood, or abnormal, such as gas that accumulates in the digestive tract due to conditions like bloating or swallowing air.

Gases can also be used medically for therapeutic purposes, such as in the administration of anesthesia or in the treatment of certain respiratory conditions with oxygen therapy. Additionally, measuring the amount of gas in the body, such as through imaging studies like X-rays or CT scans, can help diagnose various medical conditions.

Tidal volume (Vt) is the amount of air that moves into or out of the lungs during normal, resting breathing. It is the difference between the volume of air in the lungs at the end of a normal expiration and the volume at the end of a normal inspiration. In other words, it's the volume of each breath you take when you are not making any effort to breathe more deeply.

The average tidal volume for an adult human is around 500 milliliters (ml) per breath, but this can vary depending on factors such as age, sex, size, and fitness level. During exercise or other activities that require increased oxygen intake, tidal volume may increase to meet the body's demands for more oxygen.

Tidal volume is an important concept in respiratory physiology and clinical medicine, as it can be used to assess lung function and diagnose respiratory disorders such as chronic obstructive pulmonary disease (COPD) or asthma.

A lung is a pair of spongy, elastic organs in the chest that work together to enable breathing. They are responsible for taking in oxygen and expelling carbon dioxide through the process of respiration. The left lung has two lobes, while the right lung has three lobes. The lungs are protected by the ribcage and are covered by a double-layered membrane called the pleura. The trachea divides into two bronchi, which further divide into smaller bronchioles, leading to millions of tiny air sacs called alveoli, where the exchange of gases occurs.

Pulmonary ventilation, also known as pulmonary respiration or simply ventilation, is the process of moving air into and out of the lungs to facilitate gas exchange. It involves two main phases: inhalation (or inspiration) and exhalation (or expiration). During inhalation, the diaphragm and external intercostal muscles contract, causing the chest volume to increase and the pressure inside the chest to decrease, which then draws air into the lungs. Conversely, during exhalation, these muscles relax, causing the chest volume to decrease and the pressure inside the chest to increase, which pushes air out of the lungs. This process ensures that oxygen-rich air from the atmosphere enters the alveoli (air sacs in the lungs), where it can diffuse into the bloodstream, while carbon dioxide-rich air from the bloodstream in the capillaries surrounding the alveoli is expelled out of the body.

Smoke inhalation injury is a type of damage that occurs to the respiratory system when an individual breathes in smoke, most commonly during a fire. This injury can affect both the upper and lower airways and can cause a range of symptoms, including coughing, wheezing, shortness of breath, and chest pain.

Smoke inhalation injury can also lead to more severe complications, such as chemical irritation of the airways, swelling of the throat and lungs, and respiratory failure. In some cases, it can even be fatal. The severity of the injury depends on several factors, including the duration and intensity of the exposure, the individual's underlying health status, and the presence of any pre-existing lung conditions.

Smoke inhalation injury is caused by a combination of thermal injury (heat damage) and chemical injury (damage from toxic substances present in the smoke). The heat from the smoke can cause direct damage to the airways, leading to inflammation and swelling. At the same time, the chemicals in the smoke can irritate and corrode the lining of the airways, causing further damage.

Some of the toxic substances found in smoke include carbon monoxide, cyanide, and various other chemicals released by burning materials. These substances can interfere with the body's ability to transport oxygen and can cause metabolic acidosis, a condition characterized by an excessively acidic environment in the body.

Treatment for smoke inhalation injury typically involves providing supportive care to help the individual breathe more easily, such as administering oxygen or using mechanical ventilation. In some cases, medications may be used to reduce inflammation and swelling in the airways. Severe cases of smoke inhalation injury may require hospitalization and intensive care.

Respiratory Function Tests (RFTs) are a group of medical tests that measure how well your lungs take in and exhale air, and how well they transfer oxygen and carbon dioxide into and out of your blood. They can help diagnose certain lung disorders, measure the severity of lung disease, and monitor response to treatment.

RFTs include several types of tests, such as:

1. Spirometry: This test measures how much air you can exhale and how quickly you can do it. It's often used to diagnose and monitor conditions like asthma, chronic obstructive pulmonary disease (COPD), and other lung diseases.
2. Lung volume testing: This test measures the total amount of air in your lungs. It can help diagnose restrictive lung diseases, such as pulmonary fibrosis or sarcoidosis.
3. Diffusion capacity testing: This test measures how well oxygen moves from your lungs into your bloodstream. It's often used to diagnose and monitor conditions like pulmonary fibrosis, interstitial lung disease, and other lung diseases that affect the ability of the lungs to transfer oxygen to the blood.
4. Bronchoprovocation testing: This test involves inhaling a substance that can cause your airways to narrow, such as methacholine or histamine. It's often used to diagnose and monitor asthma.
5. Exercise stress testing: This test measures how well your lungs and heart work together during exercise. It's often used to diagnose lung or heart disease.

Overall, Respiratory Function Tests are an important tool for diagnosing and managing a wide range of lung conditions.

Pulmonary edema is a medical condition characterized by the accumulation of fluid in the alveoli (air sacs) and interstitial spaces (the area surrounding the alveoli) within the lungs. This buildup of fluid can lead to impaired gas exchange, resulting in shortness of breath, coughing, and difficulty breathing, especially when lying down. Pulmonary edema is often a complication of heart failure, but it can also be caused by other conditions such as pneumonia, trauma, or exposure to certain toxins.

In the early stages of pulmonary edema, patients may experience mild symptoms such as shortness of breath during physical activity. However, as the condition progresses, symptoms can become more severe and include:

* Severe shortness of breath, even at rest
* Wheezing or coughing up pink, frothy sputum
* Rapid breathing and heart rate
* Anxiety or restlessness
* Bluish discoloration of the skin (cyanosis) due to lack of oxygen

Pulmonary edema can be diagnosed through a combination of physical examination, medical history, chest X-ray, and other diagnostic tests such as echocardiography or CT scan. Treatment typically involves addressing the underlying cause of the condition, as well as providing supportive care such as supplemental oxygen, diuretics to help remove excess fluid from the body, and medications to help reduce anxiety and improve breathing. In severe cases, mechanical ventilation may be necessary to support respiratory function.

Physical exertion is defined as the act of applying energy to physically demandable activities or tasks, which results in various body systems working together to produce movement and maintain homeostasis. It often leads to an increase in heart rate, respiratory rate, and body temperature, among other physiological responses. The level of physical exertion can vary based on the intensity, duration, and frequency of the activity.

It's important to note that engaging in regular physical exertion has numerous health benefits, such as improving cardiovascular fitness, strengthening muscles and bones, reducing stress, and preventing chronic diseases like obesity, diabetes, and heart disease. However, it is also crucial to balance physical exertion with adequate rest and recovery time to avoid overtraining or injury.

Hepatopulmonary syndrome (HPS) is a pulmonary vascular disorder characterized by the abnormal dilatation of the blood vessels in the lungs and intrapulmonary shunting, leading to hypoxemia (low levels of oxygen in the blood). This condition primarily affects individuals with liver diseases, particularly those with cirrhosis.

HPS is defined by the following triad of symptoms:

1. Liver dysfunction or portal hypertension
2. Intrapulmonary vascular dilatations
3. Hypoxemia (PaO2 ≤ 80 mmHg or alveolar-arterial oxygen gradient ≥ 15 mmHg in room air)

The pathophysiology of HPS involves the production and release of vasoactive substances from the liver, which cause dilation of the pulmonary vessels. This results in ventilation-perfusion mismatch and right-to-left shunting, leading to hypoxemia. Clinical manifestations include shortness of breath, platypnea (worsening dyspnea while in the upright position), orthodeoxia (decrease in oxygen saturation when changing from supine to upright position), digital clubbing, and cyanosis.

Diagnosis is confirmed through contrast-enhanced echocardiography or macroaggregated albumin lung scan, which demonstrates intrapulmonary shunting. Treatment of HPS primarily focuses on managing the underlying liver disease and improving hypoxemia with supplemental oxygen or other supportive measures. In some cases, liver transplantation may be considered as a definitive treatment option for both the liver disease and HPS.

Hyperventilation is a medical condition characterized by an increased respiratory rate and depth, resulting in excessive elimination of carbon dioxide (CO2) from the body. This leads to hypocapnia (low CO2 levels in the blood), which can cause symptoms such as lightheadedness, dizziness, confusion, tingling sensations in the extremities, and muscle spasms. Hyperventilation may occur due to various underlying causes, including anxiety disorders, lung diseases, neurological conditions, or certain medications. It is essential to identify and address the underlying cause of hyperventilation for proper treatment.

Artificial respiration is an emergency procedure that can be used to provide oxygen to a person who is not breathing or is breathing inadequately. It involves manually forcing air into the lungs, either by compressing the chest or using a device to deliver breaths. The goal of artificial respiration is to maintain adequate oxygenation of the body's tissues and organs until the person can breathe on their own or until advanced medical care arrives. Artificial respiration may be used in conjunction with cardiopulmonary resuscitation (CPR) in cases of cardiac arrest.

Extravascular lung water (EVLW) refers to the amount of fluid that has accumulated in the lungs outside of the pulmonary vasculature. It is not a part of the normal physiology and can be a sign of various pathological conditions, such as heart failure, sepsis, or acute respiratory distress syndrome (ARDS).

EVLW can be measured using various techniques, including transpulmonary thermodilution and pulmonary artery catheterization. Increased EVLW is associated with worse outcomes in critically ill patients, as it can lead to impaired gas exchange, decreased lung compliance, and increased work of breathing.

It's important to note that while EVLW can provide valuable information about a patient's condition, it should be interpreted in the context of other clinical findings and used as part of a comprehensive assessment.

Cardiac output is a measure of the amount of blood that is pumped by the heart in one minute. It is defined as the product of stroke volume (the amount of blood pumped by the left ventricle during each contraction) and heart rate (the number of contractions per minute). Normal cardiac output at rest for an average-sized adult is about 5 to 6 liters per minute. Cardiac output can be increased during exercise or other conditions that require more blood flow, such as during illness or injury. It can be measured noninvasively using techniques such as echocardiography or invasively through a catheter placed in the heart.

An exercise test, also known as a stress test or an exercise stress test, is a medical procedure used to evaluate the heart's function and response to physical exertion. It typically involves walking on a treadmill or pedaling a stationary bike while being monitored for changes in heart rate, blood pressure, electrocardiogram (ECG), and sometimes other variables such as oxygen consumption or gas exchange.

During the test, the patient's symptoms, such as chest pain or shortness of breath, are also closely monitored. The exercise test can help diagnose coronary artery disease, assess the severity of heart-related symptoms, and evaluate the effectiveness of treatments for heart conditions. It may also be used to determine a person's safe level of physical activity and fitness.

There are different types of exercise tests, including treadmill stress testing, stationary bike stress testing, nuclear stress testing, and stress echocardiography. The specific type of test used depends on the patient's medical history, symptoms, and overall health status.

Anoxia is a medical condition that refers to the absence or complete lack of oxygen supply in the body or a specific organ, tissue, or cell. This can lead to serious health consequences, including damage or death of cells and tissues, due to the vital role that oxygen plays in supporting cellular metabolism and energy production.

Anoxia can occur due to various reasons, such as respiratory failure, cardiac arrest, severe blood loss, carbon monoxide poisoning, or high altitude exposure. Prolonged anoxia can result in hypoxic-ischemic encephalopathy, a serious condition that can cause brain damage and long-term neurological impairments.

Medical professionals use various diagnostic tests, such as blood gas analysis, pulse oximetry, and electroencephalography (EEG), to assess oxygen levels in the body and diagnose anoxia. Treatment for anoxia typically involves addressing the underlying cause, providing supplemental oxygen, and supporting vital functions, such as breathing and circulation, to prevent further damage.

Hemodynamics is the study of how blood flows through the cardiovascular system, including the heart and the vascular network. It examines various factors that affect blood flow, such as blood volume, viscosity, vessel length and diameter, and pressure differences between different parts of the circulatory system. Hemodynamics also considers the impact of various physiological and pathological conditions on these variables, and how they in turn influence the function of vital organs and systems in the body. It is a critical area of study in fields such as cardiology, anesthesiology, and critical care medicine.

Respiratory Distress Syndrome, Adult (RDSa or ARDS), also known as Acute Respiratory Distress Syndrome, is a severe form of acute lung injury characterized by rapid onset of widespread inflammation in the lungs. This results in increased permeability of the alveolar-capillary membrane, pulmonary edema, and hypoxemia (low oxygen levels in the blood). The inflammation can be triggered by various direct or indirect insults to the lung, such as sepsis, pneumonia, trauma, or aspiration.

The hallmark of ARDS is the development of bilateral pulmonary infiltrates on chest X-ray, which can resemble pulmonary edema, but without evidence of increased left atrial pressure. The condition can progress rapidly and may require mechanical ventilation with positive end-expiratory pressure (PEEP) to maintain adequate oxygenation and prevent further lung injury.

The management of ARDS is primarily supportive, focusing on protecting the lungs from further injury, optimizing oxygenation, and providing adequate nutrition and treatment for any underlying conditions. The use of low tidal volumes and limiting plateau pressures during mechanical ventilation have been shown to improve outcomes in patients with ARDS.

Exercise is defined in the medical context as a physical activity that is planned, structured, and repetitive, with the primary aim of improving or maintaining one or more components of physical fitness. Components of physical fitness include cardiorespiratory endurance, muscular strength, muscular endurance, flexibility, and body composition. Exercise can be classified based on its intensity (light, moderate, or vigorous), duration (length of time), and frequency (number of times per week). Common types of exercise include aerobic exercises, such as walking, jogging, cycling, and swimming; resistance exercises, such as weightlifting; flexibility exercises, such as stretching; and balance exercises. Exercise has numerous health benefits, including reducing the risk of chronic diseases, improving mental health, and enhancing overall quality of life.

Bicycling is defined in medical terms as the act of riding a bicycle. It involves the use of a two-wheeled vehicle that is propelled by pedaling, with the power being transferred to the rear wheel through a chain and sprocket system. Bicycling can be done for various purposes such as transportation, recreation, exercise, or sport.

Regular bicycling has been shown to have numerous health benefits, including improving cardiovascular fitness, increasing muscle strength and flexibility, reducing stress and anxiety, and helping with weight management. However, it is important to wear a helmet while bicycling to reduce the risk of head injury in case of an accident. Additionally, cyclists should follow traffic rules and be aware of their surroundings to ensure their safety and the safety of others on the road.

Pulmonary alveoli, also known as air sacs, are tiny clusters of air-filled pouches located at the end of the bronchioles in the lungs. They play a crucial role in the process of gas exchange during respiration. The thin walls of the alveoli, called alveolar membranes, allow oxygen from inhaled air to pass into the bloodstream and carbon dioxide from the bloodstream to pass into the alveoli to be exhaled out of the body. This vital function enables the lungs to supply oxygen-rich blood to the rest of the body and remove waste products like carbon dioxide.

Lung diseases refer to a broad category of disorders that affect the lungs and other structures within the respiratory system. These diseases can impair lung function, leading to symptoms such as coughing, shortness of breath, chest pain, and wheezing. They can be categorized into several types based on the underlying cause and nature of the disease process. Some common examples include:

1. Obstructive lung diseases: These are characterized by narrowing or blockage of the airways, making it difficult to breathe out. Examples include chronic obstructive pulmonary disease (COPD), asthma, bronchiectasis, and cystic fibrosis.
2. Restrictive lung diseases: These involve stiffening or scarring of the lungs, which reduces their ability to expand and take in air. Examples include idiopathic pulmonary fibrosis, sarcoidosis, and asbestosis.
3. Infectious lung diseases: These are caused by bacteria, viruses, fungi, or parasites that infect the lungs. Examples include pneumonia, tuberculosis, and influenza.
4. Vascular lung diseases: These affect the blood vessels in the lungs, impairing oxygen exchange. Examples include pulmonary embolism, pulmonary hypertension, and chronic thromboembolic pulmonary hypertension (CTEPH).
5. Neoplastic lung diseases: These involve abnormal growth of cells within the lungs, leading to cancer. Examples include small cell lung cancer, non-small cell lung cancer, and mesothelioma.
6. Other lung diseases: These include interstitial lung diseases, pleural effusions, and rare disorders such as pulmonary alveolar proteinosis and lymphangioleiomyomatosis (LAM).

It is important to note that this list is not exhaustive, and there are many other conditions that can affect the lungs. Proper diagnosis and treatment of lung diseases require consultation with a healthcare professional, such as a pulmonologist or respiratory therapist.

Vital capacity (VC) is a term used in pulmonary function tests to describe the maximum volume of air that can be exhaled after taking a deep breath. It is the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume. In other words, it's the total amount of air you can forcibly exhale after inhaling as deeply as possible. Vital capacity is an important measurement in assessing lung function and can be reduced in conditions such as chronic obstructive pulmonary disease (COPD), asthma, and other respiratory disorders.

Spirometry is a common type of pulmonary function test (PFT) that measures how well your lungs work. This is done by measuring how much air you can exhale from your lungs after taking a deep breath, and how quickly you can exhale it. The results are compared to normal values for your age, height, sex, and ethnicity.

Spirometry is used to diagnose and monitor certain lung conditions, such as asthma, chronic obstructive pulmonary disease (COPD), and other respiratory diseases that cause narrowing of the airways. It can also be used to assess the effectiveness of treatment for these conditions. The test is non-invasive, safe, and easy to perform.

Heart rate is the number of heartbeats per unit of time, often expressed as beats per minute (bpm). It can vary significantly depending on factors such as age, physical fitness, emotions, and overall health status. A resting heart rate between 60-100 bpm is generally considered normal for adults, but athletes and individuals with high levels of physical fitness may have a resting heart rate below 60 bpm due to their enhanced cardiovascular efficiency. Monitoring heart rate can provide valuable insights into an individual's health status, exercise intensity, and response to various treatments or interventions.

Respiratory transport, in the context of physiology and medicine, refers to the process of gas exchange between the environment and an organism's body or between different parts of the body. Specifically, it involves the uptake of oxygen (O2) from the atmosphere into the lungs during inhalation, its transportation through the bloodstream to the body's cells, and the release of carbon dioxide (CO2), a waste product, from the cells to the lungs during exhalation.

The process of respiratory transport is essential for providing oxygen to the body's tissues and removing carbon dioxide, which is produced as a byproduct of cellular metabolism. The efficiency of respiratory transport can be affected by various factors, including lung function, cardiovascular health, and the presence of respiratory diseases or conditions that impair gas exchange.

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.

Lactic acid, also known as 2-hydroxypropanoic acid, is a chemical compound that plays a significant role in various biological processes. In the context of medicine and biochemistry, lactic acid is primarily discussed in relation to muscle metabolism and cellular energy production. Here's a medical definition for lactic acid:

Lactic acid (LA): A carboxylic acid with the molecular formula C3H6O3 that plays a crucial role in anaerobic respiration, particularly during strenuous exercise or conditions of reduced oxygen availability. It is formed through the conversion of pyruvate, catalyzed by the enzyme lactate dehydrogenase (LDH), when there is insufficient oxygen to complete the final step of cellular respiration in the Krebs cycle. The accumulation of lactic acid can lead to acidosis and muscle fatigue. Additionally, lactic acid serves as a vital intermediary in various metabolic pathways and is involved in the production of glucose through gluconeogenesis in the liver.

Forced Expiratory Volume (FEV) is a medical term used to describe the volume of air that can be forcefully exhaled from the lungs in one second. It is often measured during pulmonary function testing to assess lung function and diagnose conditions such as chronic obstructive pulmonary disease (COPD) or asthma.

FEV is typically expressed as a percentage of the Forced Vital Capacity (FVC), which is the total volume of air that can be exhaled from the lungs after taking a deep breath in. The ratio of FEV to FVC is used to determine whether there is obstruction in the airways, with a lower ratio indicating more severe obstruction.

There are different types of FEV measurements, including FEV1 (the volume of air exhaled in one second), FEV25-75 (the average volume of air exhaled during the middle 50% of the FVC maneuver), and FEV0.5 (the volume of air exhaled in half a second). These measurements can provide additional information about lung function and help guide treatment decisions.

Lung volume measurements are clinical tests that determine the amount of air inhaled, exhaled, and present in the lungs at different times during the breathing cycle. These measurements include:

1. Tidal Volume (TV): The amount of air inhaled or exhaled during normal breathing, usually around 500 mL in resting adults.
2. Inspiratory Reserve Volume (IRV): The additional air that can be inhaled after a normal inspiration, approximately 3,000 mL in adults.
3. Expiratory Reserve Volume (ERV): The extra air that can be exhaled after a normal expiration, about 1,000-1,200 mL in adults.
4. Residual Volume (RV): The air remaining in the lungs after a maximal exhalation, approximately 1,100-1,500 mL in adults.
5. Total Lung Capacity (TLC): The total amount of air the lungs can hold at full inflation, calculated as TV + IRV + ERV + RV, around 6,000 mL in adults.
6. Functional Residual Capacity (FRC): The volume of air remaining in the lungs after a normal expiration, equal to ERV + RV, about 2,100-2,700 mL in adults.
7. Inspiratory Capacity (IC): The maximum amount of air that can be inhaled after a normal expiration, equal to TV + IRV, around 3,500 mL in adults.
8. Vital Capacity (VC): The total volume of air that can be exhaled after a maximal inspiration, calculated as IC + ERV, approximately 4,200-5,600 mL in adults.

These measurements help assess lung function and identify various respiratory disorders such as chronic obstructive pulmonary disease (COPD), asthma, and restrictive lung diseases.

I'm sorry for any confusion, but "Neon" is not a medical term. Neon is actually a noble gas, the fourth lightest and second most abundant in the Earth's atmosphere. It is used in vacuum tubes and high-voltage indicators, and in advertising signs and neon lamps. If you have any medical terms you would like me to define, please let me know!

Positive-pressure respiration is a type of mechanical ventilation where positive pressure is applied to the airway and lungs, causing them to expand and inflate. This can be used to support or replace spontaneous breathing in patients who are unable to breathe effectively on their own due to conditions such as respiratory failure, neuromuscular disorders, or sedation for surgery.

During positive-pressure ventilation, a mechanical ventilator delivers breaths to the patient through an endotracheal tube or a tracheostomy tube. The ventilator is set to deliver a specific volume or pressure of air with each breath, and the patient's breathing is synchronized with the ventilator to ensure proper delivery of the breaths.

Positive-pressure ventilation can help improve oxygenation and remove carbon dioxide from the lungs, but it can also have potential complications such as barotrauma (injury to lung tissue due to excessive pressure), volutrauma (injury due to overdistention of the lungs), hemodynamic compromise (decreased blood pressure and cardiac output), and ventilator-associated pneumonia. Therefore, careful monitoring and adjustment of ventilator settings are essential to minimize these risks and provide safe and effective respiratory support.

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.

Inhalation is the act or process of breathing in where air or other gases are drawn into the lungs. It's also known as inspiration. This process involves several muscles, including the diaphragm and intercostal muscles between the ribs, working together to expand the chest cavity and decrease the pressure within the thorax, which then causes air to flow into the lungs.

In a medical context, inhalation can also refer to the administration of medications or therapeutic gases through the respiratory tract, typically using an inhaler or nebulizer. This route of administration allows for direct delivery of the medication to the lungs, where it can be quickly absorbed into the bloodstream and exert its effects.

Insensible water loss is the unnoticeable or unperceived loss of water from the body through processes such as respiration, evaporation from the skin, and perspiration that is too fine to be seen or felt. It is a normal physiological process and typically accounts for about 400-800 milliliters (ml) of water loss per day in a healthy adult at rest. However, this amount can increase with factors such as environmental temperature, humidity, and altitude, as well as physical activity or illness that increases metabolic rate or alters body temperature regulation.

Insensible water loss is an important factor to consider in maintaining fluid balance in the body, particularly in individuals who are unable to regulate their own fluid intake, such as critically ill patients or those with impaired consciousness. Prolonged or excessive insensible water loss can lead to dehydration and electrolyte imbalances, which can have serious consequences on various organ systems and overall health.

Plant transpiration is the process by which water vapor escapes from leaves and other aerial parts of plants to the atmosphere. It is a type of evapotranspiration, which refers to both evaporation from land surfaces and transpiration from plants. Water molecules are absorbed by plant roots from the soil, move up through the xylem tissue to the leaves, and then evaporate from the leaf surface through stomatal pores. This process helps in the transportation of nutrients from the soil to various parts of the plant, regulates the temperature of the plant, and maintains the turgor pressure within the cells. Plant transpiration is influenced by environmental factors such as light intensity, temperature, humidity, and wind speed.

Liquid ventilation is a medical procedure that involves the use of an oxygen-rich liquid, such as perfluorocarbons (PFCs), to replace air in the lungs. This technique is used to improve gas exchange and lung function in patients with severe respiratory distress syndrome (RDS) or other forms of acute lung injury.

During liquid ventilation, the liquid is instilled into the lungs through a special endotracheal tube, causing the alveoli (tiny air sacs in the lungs) to fill up and float in the liquid. The PFCs used in liquid ventilation are capable of dissolving large amounts of oxygen and carbon dioxide, allowing for efficient gas exchange between the lungs and the bloodstream.

The use of liquid ventilation has been shown to improve lung compliance, reduce lung injury, and decrease the need for mechanical ventilation in some patients with severe respiratory distress. However, further research is needed to fully understand its potential benefits and risks.

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"The physiological basis of pulmonary gas exchange: implications for clinical interpretation of arterial blood gases". European ... "22.4 Gas Exchange - Anatomy and Physiology , OpenStax". Retrieved 2020-12-06. "3.1 The Cell Membrane - Anatomy ... A biological example of diffusion is the gas exchange that occurs during respiration within the human body. Upon inhalation, ... Because the gasses are small and uncharged, they are able to pass directly through the cell membrane without any special ...
"The physiological basis of pulmonary gas exchange: implications for clinical interpretation of arterial blood gases". European ... One example of passive diffusion is the gas exchange that occurs between the oxygen in the blood and the carbon dioxide present ...
Driehuys, B.; Möller, H.E.; Cleveland, Z.I.; Pollaro, J.; Hedlund, L.W. (2009). "Pulmonary perfusion and xenon gas exchange in ... When a patient inhales hyperpolarized xenon-129 ventilation and gas exchange in the lungs can be imaged and quantified. Unlike ... Breathing mixes gases of different densities very effectively and rapidly so that heavier gases are purged along with the ... It has the lowest thermal conductivity and lowest ionization potential of all the non-radioactive noble gases. As a noble gas, ...
In those with an acute exacerbation of COPD, hypoxic pulmonary vasoconstriction can improve gas exchange, and so just enough ... Many people with chronic obstructive pulmonary disease have a low partial pressure of oxygen in the blood and high partial ... In some individuals, the effect of oxygen on chronic obstructive pulmonary disease is to cause increased carbon dioxide ... In people with chronic obstructive pulmonary disease, carbon dioxide toxicity can be prevented by careful control of the ...
Raymond L, Dolan W, Dutton R, et al: Pulmonary function and gas exchange during altitude hypoxia (abstract). Clin Res 19:147, ... in the inspired gas are in equilibrium with their dissolved states in the blood Inspired and alveolar gases obey the ideal gas ... The equation relies on the following assumptions: Inspired gas contains no carbon dioxide (CO2) Nitrogen (and any other gases ... Pulmonary gas pressures Curran-Everett D (June 2006). "A classic learning opportunity from Fenn, Rahn, and Otis (1946): the ...
Most gas exchange occurs in the pulmonary region due to the alveoli, which contain a large surface area. Scientists have ... Since the gas takes time to build up in the pulmonary region, an inhaled concentration of 600 ppm would cause a headache and ... Carbon monoxide is a relatively nonreactive gas with limited solubility. High CO levels build up in the pulmonary region over ... Once the gases are absorbed into the mucus or surfactant layer, the dissolved gases can desorb back to the air in the lungs. ...
Marshall BE, Hanson CW, Frasch F, Marshall C: Role of HPV in pulmonary gas exchange and blood flow distribution. ... Hanson CW, Marshall BE, Frasch HF, Marshall C: The causes of hypercarbia in patients with chronic obstructive pulmonary disease ...
... abnormal gas exchange and pulmonary hypertension. COPD is most common in people over fifty who have a long history of smoking. ... Smoking is the main risk factor but inhalation of toxic and harmful particles and gases can also cause the disease. The ... and long-acting β2-agonists are used to treat chronic obstructive pulmonary disease. COPD causes airflow limitations in the ... of once-daily umeclidinium/vilanterol 125/25 mcg and umeclidinium 125 mcg in patients with chronic obstructive pulmonary ...
Blood reaches from the pulmonary circulation into the lungs for gas exchange to oxygenate the rest of the body tissues. But ... Bronchial arteries carry oxygenated blood to the lungs Pulmonary capillaries, where there is exchange of water, oxygen, carbon ... but it can still occur in pulmonary embolism when the pulmonary circulation is blocked and the bronchial circulation cannot ... Venous blood from the bronchi inside the lungs drains into the pulmonary veins and empties into the left atrium; since this ...
"22.4 Gas Exchange - Anatomy and Physiology". Archived from the original on 2020-10-19. Retrieved 2019-05-22. " ... Pulmonary circuit Transverse section of thorax, showing relations of pulmonary artery. Pulmonary artery Pulmonary artery.Deep ... The largest pulmonary artery is the main pulmonary artery or pulmonary trunk from the heart, and the smallest ones are the ... The pulmonary trunk splits into the right and the left main pulmonary artery. The left main pulmonary artery is shorter than ...
They are known for their device, AGM100, which provides non-invasive pulmonary gas exchange measurements in a short period of ...
An abrupt stop of pulmonary gas exchange lasting for more than five minutes may permanently damage vital organs, especially the ... Lower airway: may occur from bronchospasm, drowning, or airspace filling disorders (e.g. pneumonia, pulmonary edema, pulmonary ... The time depends on pulse rate, pulmonary function, RBC count, and other metabolic factors. Lidocaine can be given in 1.5 mg/kg ...
Lung parenchyma is the substance of the lung that is involved with gas exchange and includes the pulmonary alveoli. The liver ...
... related to both the breath sampling protocols as well as the complex physiological mechanisms underlying pulmonary gas exchange ... Gas chromatography-mass spectrometry GC-MS Gas chromatography-UV spectrometry GC-UV Proton transfer reaction mass spectrometry ... Breath gas analysis is used in a number of breath tests. Asthma detection by exhaled nitric oxide Blood alcohol testing Carbon ... Breath gas analysis is a method for gaining information on the clinical state of an individual by monitoring volatile organic ...
At this point, pulmonary capillaries have formed and continue to expand, creating a large surface area for gas exchange. The ... Prior to 26 weeks, sufficient pulmonary surfactant is not produced, and the surfaces for gas exchange have not formed ... Pulmonary surfactant is critical for inflation to occur, as it reduces the surface tension of the alveoli. Preterm birth around ... Once type II cells have differentiated, they begin to secrete small amounts of pulmonary surfactant. Around week 20, fetal ...
Efficient pulmonary gas exchange. Lydia Goehr, Professor of Philosophy, Columbia University: The concept of musicality in ... Tin-Lun Ho, Professor of Physics, Ohio State University: The new physics of quantum gases of alkali atoms. Robert Hooper, ...
... its occurrence is rare compared to unilateral pulmonary agenesis. The fetus loses the ability to do gas exchange post-delivery ... Pulmonary angiography assists in detecting the presence of pulmonary artery branches, differentiating pulmonary agenesis to ... Verwey, Charl; Van der Merwe, Cornelis; Pillay, Tanyia (April 28, 2017). "Pulmonary agenesis, pulmonary aplasia and pulmonary ... pulmonary agenesis and aplasia differ from pulmonary hypoplasia in their underlying cause. Unlike pulmonary hypoplasia which in ...
... when the pulmonary circulation and gas exchange was proposed by Ibn Al-Nafis. Both long since proven theories are incomplete ... Moreover, the one-way valves in the heart, like those in the veins, indicate that, following the pulmonary circulation, the ...
A new study examines the pulmonary responses to exercise in Kenyan runners. Do they differ from that of non-Kenyan athletes? ... Pulmonary Mechanics and Gas Exchange During Exercise in Kenyan Distance Runners. Glen E. Foster; Michael S. Koehle; Paolo B. ... Conclusions: Pulmonary system limitations were present in Kenyan runners in the form of exercise-induced arterial hypoxemia, ... Reported pulmonary system limitations to exercising humans include (i) exercise-induced arterial hypoxemia (EIAH);[9] (ii) ...
... gas exchange, respiration control, and lung injury that can be used to enhance conventional mechanical ventilation (CMV) so as ... other mechanisms of gas exchange (variable velocity profiles of gas during inspiration and exhalation, gas exchange between ... Impaired Gas Exchange. Newborns are vulnerable to impaired gas exchange because of their relatively high metabolic rate, ... This article reviews assisted ventilation of the newborn, highlighting the concepts of pulmonary mechanics, gas exchange, ...
Fast-growing broiler chickens not uncommonly exhibit elevated pulmonary vascular resistance that leads to pulmonary ... Influence of feed deprivation on ventilation and gas exchange in broilers: relationship to pulmonary hypertension syndrome M R ... Influence of feed deprivation on ventilation and gas exchange in broilers: relationship to pulmonary hypertension syndrome M R ... Independent and simultaneous unilateral occlusion of the pulmonary artery and extra-pulmonary primary bronchus in broilers. ...
Measurement of Gas Exchange - Etiology, pathophysiology, symptoms, signs, diagnosis & prognosis from the MSD Manuals - Medical ... In pulmonary hypertension, pulmonary vessels may become constricted... read more and pulmonary embolism Pulmonary Embolism (PE ... pulmonary embolism Pulmonary Embolism (PE) Pulmonary embolism (PE) is the occlusion of pulmonary arteries by thrombi that ... Hypocapnia is always caused by hyperventilation due to pulmonary (eg, pulmonary edema Pulmonary Edema Pulmonary edema is acute ...
... gas exchange, respiration control, and lung injury that can be used to enhance conventional mechanical ventilation (CMV) so as ... other mechanisms of gas exchange (variable velocity profiles of gas during inspiration and exhalation, gas exchange between ... Impaired Gas Exchange. Newborns are vulnerable to impaired gas exchange because of their relatively high metabolic rate, ... This article reviews assisted ventilation of the newborn, highlighting the concepts of pulmonary mechanics, gas exchange, ...
This table contains the mapping between the system Data Element Permissible Value and external entity schema IDs and Permissible Values Data element Variable Name: PulmGasExchngO2SaturVal ...
Search for abbreviations and long forms in lifescience, always up-to-date
Repeat pulmonary function and gas exchange tests. The most sensitive physiologic test for the detection of CBD is the ... including pulmonary function tests, measurement of DLCO, and exercise capacity testing (preferably with an arterial blood gas ... and the remainder have a mixed pattern of obstruction and restriction with varying amounts of gas exchange abnormality (Newman ... The exercise capacity test reveals gas exchange or ventilatory abnormalities, including an elevation in the dead space-to-tidal ...
Pulmonary Disease, Chronic Obstructive / therapy* * Pulmonary Gas Exchange / physiology * Respiration, Artificial / methods* ...
Gas exchange takes place in the pulmonary region. Particles deposit in the lung by inertial impaction, sedimentation, diffusion ... In: Climate and Health Implications of Bubble-Mediated Sea-Air Exchange (Monahan EC, Van Patten MA, eds). Groton, CT: ... TB and pulmonary region). The inhaled red tide aerosol has high deposition efficiency in the respiratory tract; thus, the ... PbTx levels in air and seawater were measured and personal interviews and pulmonary function tests were conducted on people ...
Pulmonary Gas Exchange; Pulmonary Surfactants/metabolism; Trachea/drug effects; Trachea/physiology; Water-Electrolyte Balance ... Aqp5 knockout (Aqp5(-/-)) mice were used to analyze AQP5 function in pulmonary physiology. Compared with Aqp5(+/+) mice, Aqp5 ...
Ventilation-perfusion and gas exchange and pulmonary circulation. I worked extensively on pulmonary circulation. ... FYE: And cardiac catheterization came into play because of his interest in pulmonary gas exchange and cardiac output. ... Herman Rahns main interest was in gas exchange in the lung and at the periphery. I viewed that as being a kind of a compromise ... His work has been on gas exchange and the homogeneity of the lung. He has done lots of work on pressure breathing, basically ...
Pulmonary function: devices to assess pulmonary arterial pressures; gas exchange, airway pressure, lung volumes, ventilation/ ...
Influence of feed deprivation on ventilation and gas exchange in broilers: relationship to pulmonary hypertension syndrome. ...
The ongoing process of breathing underlies the gas exchange essential for mammalian life. Each respiratory cycle ensues from ... Pulmonary Gas Exchange / physiology Actions. * Search in PubMed * Search in MeSH * Add to Search ... The ongoing process of breathing underlies the gas exchange essential for mammalian life. Each respiratory cycle ensues from ... pulmonary stretch receptors; ramp-I - ramp-inspiratory neuron; RTN - retrotrapezoid nucleus; rVRG - rostral ventral respiratory ...
4. Pulmonary Gas Exchange Abnormalities in Mild Chronic Obstructive Pulmonary Disease. Implications for Dyspnea and Exercise ... Does the respiratory system limit exercise in mild chronic obstructive pulmonary disease?. Chin RC; Guenette JA; Cheng S; ... 1. Mechanisms of dyspnea during cycle exercise in symptomatic patients with GOLD stage I chronic obstructive pulmonary disease. ... 2. Combined effects of obesity and chronic obstructive pulmonary disease on dyspnea and exercise tolerance.. Ora J; Laveneziana ...
Contribution of multiple inert gas elimination technique to pulmonary medicine--4. Gas exchange abnormalities in pulmonary ... Emergency TEE was performed and showed a large pulmonary embolus in the pulmonary trunk and the right and left pulmonary ... which shows a large embolus in the pulmonary trunk (pulmonary artery) and in both the right and the left pulmonary artery (see ... Deep Vein Thrombosis and Pulmonary Embolism in the Operating Room * Sections Deep Vein Thrombosis and Pulmonary Embolism in the ...
... and gas exchange in patients with chronic obstructive pulmonary disease and pulmonary hypertension. Am Rev Respir Dis. 1984;129 ... In patients with pulmonary hypertension (PH) and chronic obstructive pulmonary disease (COPD), hydralazine may increase ... unchanged pulmonary vascular resistance, increased pulmonary artery pressure, decreased systemic vascular resistance, and ... Cases of acute pulmonary edema, interstitial cystitis, interstitial nephritis, and anaphylaxis have been associated with HCTZ ...
... studies might include pulmonary function studies to evaluate for airflow limitation and abnormalities in gas exchange; chest ... What pulmonary tests have you done so far? Im in a pretty similar situation where I had a one time exposure to quartz dust ... I sought the care of a Pulmonary care provider, and he states I have Dyspnea, which is secondary to reactive airway disease, ... For example, hazardous silica exposures have been newly documented in the United States during hydraulic fracturing of gas and ...
Several different pulmonary, cardiac and cardiovascular abnormalities have negative effects on pulmonary gas-exchange. ... In vivo Xenon-129 gas-exchange magnetic resonance imaging (129Xe gas-exchange MRI) has the potential to overcome these ... Novel 129xe Magnetic Resonance Imaging And Spectroscopy Measurements Of Pulmonary Gas-Exchange, Alexander M. Matheson Mar 2023 ... Gas-exchange is the primary function of the lungs and involves removing carbon dioxide from the body and exchanging it within ...
Long, durable fibers deposited in the gas-exchange region of the lung can lead to long-term inflammation, pulmonary fibrosis, ... Fibers deposited in the deepest parts of the lungs where gas exchange occurs are removed more slowly by special cells called ... Synthetic vitreous fibers deposited in the gas exchange area of the lungs also slowly dissolve in lung fluid. Fibers that are ... If pulmonary inflammation continues, the cells lining the lung may thicken from a process called bronchiolization. ...
... to enable non-invasive imaging of pulmonary gas exchange. The successful development of such a technology could provide a ... protocol to detect regional gas exchange abnormalities associated with PVD. It will do so by advancing a novel technology that ... New drug for pulmonary arterial hypertension. - Vascular Interventions/Innovations and Therapeutic Advances (VITA) Program Tom ... Pulmonary arterial hypertension (PAH) is a debilitating disease that involves remodeling of the arterial blood vessels in the ...
Effects of the vapor on pulmonary airways, pulmonary gas exchange, the regulation of pulmonary ventilation and hemoglobin ... vapors affects hemoglobin affinity for oxygen and/or pulmonary function, four healthy young males aged 22 to 24 years were ...
Pulmonary function or gas exchange during exercise was not affected by the presence of circumscribed pleural plaques or diffuse ... Impaired gas exchange, as manifested by increases in the physiological dead space volume/tidal volume (VD/VT) ratio and ... NIOSH-Grant; Pulmonary-system-disorders; Asbestos-workers; Occupational-exposure; Chest-X-rays; Pulmonary-function-tests; Lung- ... Resting pulmonary function testing was performed. The subjects instrumented with electrocardiographs exercised on a cycle ...
Updated by: Frank D. Brodkey, MD, FCCM, Associate Professor, Section of Pulmonary and Critical Care Medicine, University of ... During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to ... Gas exchange allows the body to replenish the oxygen and eliminate the carbon dioxide. Doing both is necessary for survival. ...
Pulmonary Elimination G9.772.770.723 G9.772.625 Pulmonary Gas Exchange G3.495.166.775.602 G3.143.775.602 G9.772.770.755.760.602 ... Pulmonary Aspergillosis C1.703.80.768 Pulmonary Circulation G9.330.190.163.770 G9.330.100.770 G9.772.770.690 G9.772.593 ... Ion Exchange G2.149.767.640 G2.437 G2.842.750.640 Ion Transport G3.495.166.500 G3.143.500 Ipratropium D4.75.80.875.99.722. ... Anion Exchange Protein 1, Erythrocyte D12.776.157.530.937.625.249.500 D12.776.543.585.937.750.249.500 Anisotropy G2.842.50 ...
... of fluid overload and subsequent ill-effects including interference with gas exchange due to the development of pulmonary edema ... Microvascular fluid exchange and the revised Starling principle. Cardiovasc Res. (2010) 87:198-210. doi: 10.1093/cvr/cvq062 ... Pantaleon LG, Furr MO, Mckenzie HC, Donaldson L. Cardiovascular and pulmonary effects of hetastarch plus hypertonic saline ... Revised Starling equation and the glycocalyx model of transvascular fluid exchange: an improved paradigm for prescribing ...
Pulmonary Gas Exchange - Preferred Concept UI. M0018136. Scope note. The exchange of OXYGEN and CARBON DIOXIDE between alveolar ... Pulmonary Gas Exchange Entry term(s). Exchange, Pulmonary Gas Gas Exchange, Pulmonary ... The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR ... Exchange, Pulmonary Gas. Gas Exchange, Pulmonary. Tree number(s):. E01.370.386.700.650. G03.143.775.602. G09.772.705.760.602. ...
PULM GAS EXCHANGE. Entry Term(s). Exchange, Pulmonary Gas Gas Exchange, Pulmonary NLM Classification #. WF 105. See Also. Blood ... Pulmonary Gas Exchange Preferred Concept UI. M0018136. Scope Note. The exchange of OXYGEN and CARBON DIOXIDE between alveolar ... Pulmonary Gas Exchange [E01.370.386.700.650] * Pulmonary Diffusing Capacity [E01.370.386.700.650.650] ... Pulmonary Gas Exchange Preferred Term Term UI T034445. Date01/01/1999. LexicalTag NON. ThesaurusID NLM (1983). ...
  • Pulmonary Embolism (PE) Pulmonary embolism (PE) is the occlusion of pulmonary arteries by thrombi that originate elsewhere, typically in the large veins of the legs or pelvis. (
  • Risk factors for pulmonary embolism are. (
  • Colloquially known as blood clots, deep vein thrombosis (DVT) and pulmonary embolism (PE) are forms of venous thromboembolism (VTE). (
  • It can also be classified according to its severity, which is determined on the basis of the presence or absence of hemodynamic instability, the presence or absence of respiratory symptoms, and the anatomic location of the embolism in the pulmonary vasculature. (
  • The treatment of pulmonary embolism and the prevention of new episodes require that the thromboembolic episode, even if poorly symptomatic, involves hospital admission for study and early treatment. (
  • Reducing the factors predisposing to venous stasis will prevent thrombosis and its consequence, pulmonary embolism. (
  • Here, a blood clot, or specifically in your example, a pulmonary embolism, increases the resistance in one of a number of vessels in parallel. (
  • This is useful in a helpful clot at the site of injury as well as an unhelpful clot like a pulmonary embolism. (
  • A venous air embolism occurs when air enters venous circulation and moves to the right ventricle of the heart and then into pulmonary circulation where it becomes lodged. (
  • Because it enters pulmonary circulation, you may see this referred to as a pulmonary air embolism. (
  • Venous air embolism can also cause tissue damage in the lungs which leads to the accumulation of neutrophils, platelets and other inflammatory substances collecting where gas exchange should take place. (
  • Pulmonary embolism (PE) is a potentially fatal condition that occurs as a result of intraluminal obstruction of the main pulmonary artery or its branches. (
  • The lecture Pulmonary Embolism: Diagnosis by Carlo Raj, MD is from the course Disorders of the Pulmonary Circulation and the Respiratory Regulation. (
  • What is the classic ECG pattern associated with pulmonary embolism? (
  • Fast-growing broiler chickens not uncommonly exhibit elevated pulmonary vascular resistance that leads to pulmonary hypertension and right ventricular failure. (
  • Pulmonary Hypertension Pulmonary hypertension is increased pressure in the pulmonary circulation. (
  • In pulmonary hypertension, pulmonary vessels may become constricted. (
  • and pulmonary hypertension. (
  • The pulmonary hypertension that occurs can be greater in case of previous heart or pulmonary disease, such as mitral stenosis or COPD. (
  • Pulmonary hypertension can cause a dull, substernal discomfort. (
  • Chronic Obstructive Pulmonary Disease (COPD) Chronic obstructive pulmonary disease (COPD) is airflow limitation caused by an inflammatory response to inhaled toxins, often cigarette smoke. (
  • 1. Mechanisms of dyspnea during cycle exercise in symptomatic patients with GOLD stage I chronic obstructive pulmonary disease. (
  • 2. Combined effects of obesity and chronic obstructive pulmonary disease on dyspnea and exercise tolerance. (
  • 4. Pulmonary Gas Exchange Abnormalities in Mild Chronic Obstructive Pulmonary Disease. (
  • 7. Inhaled fentanyl citrate improves exercise endurance during high-intensity constant work rate cycle exercise in chronic obstructive pulmonary disease. (
  • 11. Does the respiratory system limit exercise in mild chronic obstructive pulmonary disease? (
  • 14. Low resting diffusion capacity, dyspnea, and exercise intolerance in chronic obstructive pulmonary disease. (
  • 17. Evolution of dyspnea during exercise in chronic obstructive pulmonary disease: impact of critical volume constraints. (
  • This article reviews assisted ventilation of the newborn, highlighting the concepts of pulmonary mechanics, gas exchange, respiration control, and lung injury that can be used to optimize respiratory support and the use of mechanical ventilation in newborn infants. (
  • The effect of assisted ventilation on hypercapnia depends on the mechanism of gas-exchange impairment. (
  • In erythrocythemia, DLCO is increased because hematocrit is increased and because of the vascular recruitment that occurs with increased pulmonary pressures due to increased viscosity. (
  • When this occurs, patients can experience increased pulmonary pressures, increased pulmonary vascular resistance, and increased pressure in the right ventricle. (
  • The DLCO increase in heart failure presumably because the increased pulmonary venous and arterial pressure recruits additional pulmonary microvessels. (
  • The emboli released into the venous flow spread in 65% of the cases to both lungs, and less unilaterally, affecting both pulmonary mechanics and hemodynamics, and the gas exchange with arterial hypoxemia and in some case pulmonary infarction. (
  • An embolus is a blood clot that usually develops in the leg veins in individuals with deep venous thrombosis, detaches and travels to a certain pulmonary artery and blocks it. (
  • This leads to increased central venous pressure, decreased pulmonary pressure and hypotension. (
  • If venous air passes through the pulmonary capillary bed and enters the arterial side, organ ischemia can occur, including cardiac ischemia if the coronary arteries are affected. (
  • Pulmonary system limitations were present in Kenyan runners in the form of exercise-induced arterial hypoxemia, expiratory flow limitation, and high levels of respiratory muscle work. (
  • Hypercapnia and hypoxemia frequently coexist, though some disorders may affect gas exchange differentially. (
  • Thus, limitation of gas intake at the mouth was not the cause of the hypoxemia. (
  • 2001). For many patients with CBD, results of resting pulmonary function tests, including spirometry values, lung volumes, and carbon monoxide-diffusing capacity (DLCO), are normal but resting and exercise arterial blood gas levels indicate hypoxemia. (
  • Patients may experience pulmonary edema, hypoxemia, increased airway resistance and bronchoconstriction. (
  • mean ± SD age = 25.2 ± 1.3 yr) were instrumented with a radial artery catheter, an esophageal balloon-tipped catheter, and an esophageal temperature probe for the determination of blood gases, the work of breathing and core temperature, respectively. (
  • The sudden lodging of a blood clot in a pulmonary artery with the subsequent obstruction of blood flow to the parenchyma is estimated to occur in 5% of individuals dying out of hospital and in 25% of those dying at the hospital. (
  • From there it flows into the right ventricle and out through the pulmonary artery into pulmonary circulation. (
  • Idiopathic Pulmonary Fibrosis Idiopathic pulmonary fibrosis (IPF), the most common form of idiopathic interstitial pneumonia, causes progressive pulmonary fibrosis. (
  • Lung histopathology reveals interstitial infiltration with mononuclear cells, well-defined noncaseating granulomas (sometimes with multinucleated giant cells and calcific inclusions), and varying degrees of pulmonary fibrosis (Meyer 1994). (
  • In the present study, we questioned whether Kenyan runners experience pulmonary limitations during exercise as has been commonly reported in other endurance athletes. (
  • Oxygen uptake (VO2), carbon-dioxide production (VCO2), respiratory exchange rate, tidal volume, and other variables related to respiratory function were monitored. (
  • Gas exchange allows the body to replenish the oxygen and eliminate the carbon dioxide. (
  • The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER. (
  • The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged. (
  • The purpose of this study was to determine arterial blood gases, the mechanical limits for generating expiratory flow and the work performed by the respiratory muscles during treadmill exercise in Kenyan runners. (
  • The exercise capacity test reveals gas exchange or ventilatory abnormalities, including an elevation in the dead space-to-tidal volume ratio, in most patients with CBD. (
  • Of those with pulmonary function abnormalities, one third of patients present with an obstructive pattern, one fourth with a restrictive pattern of decreased lung volumes, one third with an isolated decreased DLCO, and the remainder have a mixed pattern of obstruction and restriction with varying amounts of gas exchange abnormality (Newman and Maier 2001). (
  • Optimal V/Q matching occurs when the ratio of the volume of gas to the volume of blood entering the lungs approximates 1. (
  • During gas exchange oxygen moves from the lungs to the bloodstream. (
  • Pulmonary edema is an abnormal buildup of fluid in the lungs. (
  • exchanged in the lungs so that breathing can take place. (
  • In PE, gas exchange is impaired due to the decreased return of deoxygenated blood to the lungs. (
  • Pulmonary edema is often caused by congestive heart failure . (
  • Pulmonary edema is almost always treated in the emergency room or hospital. (
  • The cause of pulmonary edema should be identified and treated quickly. (
  • In critically ill patients, fluid overload is related to increased mortality and also lead to several complications like pulmonary edema, cardiac failure, delayed wound healing, tissue breakdown, and impaired bowel function. (
  • In concert with these data, the control and optimization of fluid balance is a key element of critically ill patients management, since inadequate fluid removal is associated with peripheral edema and pulmonary edema, which can retard weaning from mechanical ventilation, or compromise wound healing. (
  • However, larger air embolisms can obstruct pulmonary circulation leading to obstructive shock and cardiovascular collapse. (
  • Large bubbles of air usually block the pulmonary outflow tract which decreases the circulation of blood from the right side of the heart. (
  • The diffusing capacity for carbon monoxide (DLCO) is a measure of the ability of gas to transfer from the alveoli across the alveolar epithelium and the capillary endothelium to the red blood cells. (
  • The symptoms depend on the extension of the vascular occlusion, the previous cardiopulmonary disease, and the development of pulmonary infarction. (
  • Pulmonary infarction is when some of the lung tissue does not receive enough blood flow and oxygen and appears on imaging studies to die due to blockage of a lung blood vessel by a pulmonary embolus. (
  • Intra-pulmonary veno-arterial shunting of blood commonly occurs through lung segments with alveolar hypoventilation. (
  • Impaired gas exchange, as manifested by increases in the physiological dead space volume/tidal volume (VD/VT) ratio and alveolar arterial oxygen pressure difference, was seen in subjects with asbestos is. (
  • Relations between ventilator-controlled variables (shaded circles) and pulmonary mechanics (unshaded circles) that determine minute ventilation during pressure-limited time-cycled ventilation. (
  • Dashed lines represent relations that cannot be calculated precisely without considering other variable such as pulmonary mechanics. (
  • In order to determine whether daily exposure to methylene chloride (75092) vapors affects hemoglobin affinity for oxygen and/or pulmonary function, four healthy young males aged 22 to 24 years were exposed for 7-1/2 hours per day for 26 days in an environmental chamber over 6 consecutive weeks to various concentrations (0 to 50ppm) of methylene-chloride vapor. (
  • Effects of the vapor on pulmonary airways, pulmonary gas exchange, the regulation of pulmonary ventilation and hemoglobin affinity for oxygen were examined. (
  • The symptoms can be acute or chronic, and diagnosis is usually based on radiographic findings, typically a CT pulmonary angiogram. (
  • Most emboli lodge in pulmonary arteries of large or intermediate gauge, and less than 35% reach the small arteries. (
  • and if this blood clot is formed in pulmonary thrombosis, this can reduce gas exchange in lung. (
  • We tested the hypothesis that a distended gastrointestinal tract in these full-fed birds results in an abnormally low tidal volume and minute ventilation that could lead to pulmonary hypoxia, pulmonary arterial vasoconstriction, right ventricular failure, and ascites. (
  • Aqp5 knockout (Aqp5(-/-)) mice were used to analyze AQP5 function in pulmonary physiology. (
  • These T-Valves are suitable for exercise physiology, pulmonary function, and even MRI applications. (
  • The data suggest that feed deprivation results in an increase in parabronchial ventilation, possibly from improvement in aerodynamic valving, which would reduce pulmonary hypoxic vasoconstriction and right ventricular failure. (
  • If the bubbles of air are small, they usually obstruct pulmonary microcirculation, which impairs blood flow and also causes vasoconstriction (which further impairs blood flow). (
  • Blood gases and hematocrit were measured separately but under identical conditions. (
  • The DLCO depends not only on the area and thickness of the blood-gas barrier but also on the volume of blood in the pulmonary capillaries. (
  • Each respiratory cycle ensues from the activity of rhythmic neural circuits in the brainstem, shaped by various modulatory signals, including mechanoreceptor feedback sensitive to lung inflation and chemoreceptor feedback dependent on gas composition in blood and tissues. (
  • This oxygenated blood then returns to the heart via the pulmonary veins. (
  • [ 19 , 35 ] The above-mentioned pulmonary system limitations are important determinants of exercise performance, but to our knowledge, there are no published reports dealing with the pulmonary responses to exercise in Kenyan runners. (
  • Toads experiencing dehydrating conditions exhibit complex physiological and behavioral responses, some of which can potentially impact cutaneous gas exchange, an important component of total gas exchange. (
  • The authors conclude that asbestos induced circumscribed pleural plaques and diffuse pleural thickening are independently associated with decrements in gas exchange during maximal exercise. (
  • Pulmonary function tests are a group of diagnostic procedures yielding useful, quantifiable information about the rate of the flow of air through the individual's airways, lung capacity, and the efficiency of gas exchange in relation to time. (
  • While providing a wealth of anatomical information necessary for the diagnosis of pulmonary disease, chest X-rays do not give much information about the individual's respiratory function. (
  • Pulmonary-hematologic studies on humans during exposure to methylene chloride. (
  • DLCO is measured by sampling end-expiratory gas for carbon monoxide (CO) after patients inspire a small amount of carbon monoxide, hold their breath, and exhale. (
  • Newborns are vulnerable to impaired gas exchange because of their relatively high metabolic rate, propensity for decreased functional residual capacity (FRC), decreased lung compliance, increased resistance, and potential for right-to-left shunts through the ductus arteriosus , foramen ovale , or both. (
  • The new gas analysis system provides a powerful tool for metabolic studies. (
  • Measure expired O 2 and CO 2 with lessons for VO 2 max, respiratory exchange ratio, and basal or resting metabolic rate. (
  • The gas analysis system and a range of airflow and pressure transducers will accommodate metabolic, respiratory and pulmonary measurements on a variety of species. (
  • It appears that Kenyan runners do not posses a pulmonary system that confers a physiological advantage. (
  • Ventilation may be required during immediate care of the infant who is in respiratory failure due to birth depression, encephalopathy, apnea, shock, or pulmonary disease. (
  • The resulting V/Q mismatch is probably the most important mechanism of impaired gas exchange among infants with respiratory failure due to lung disease, including respiratory distress syndrome (RDS). (
  • My research focuses on mechanisms of impaired pulmonary gas exchange in various disease states, and how knowledge of these may be used for diagnostics and targeted treatments. (
  • Optimal ventilatory strategies provide the best possible gas exchange, while minimizing lung injury or other adverse effects. (
  • Pulmonary function or gas exchange during exercise was not affected by the presence of circumscribed pleural plaques or diffuse pleural thickening. (
  • The SS46L pneumotach can perform a variety of pulmonary measurements relating to airflow, lung volume, and expired gas analysis. (

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