Nerve fibers which project from cell bodies of AUTONOMIC GANGLIA to SYNAPSES on target organs.
NERVE FIBERS which project from the central nervous system to AUTONOMIC GANGLIA. In the sympathetic division most preganglionic fibers originate with neurons in the intermediolateral column of the SPINAL CORD, exit via ventral roots from upper thoracic through lower lumbar segments, and project to the paravertebral ganglia; there they either terminate in SYNAPSES or continue through the SPLANCHNIC NERVES to the prevertebral ganglia. In the parasympathetic division the fibers originate in neurons of the BRAIN STEM and sacral spinal cord. In both divisions the principal transmitter is ACETYLCHOLINE but peptide cotransmitters may also be released.
Nerve fibers which project from sympathetic ganglia to synapses on target organs. Sympathetic postganglionic fibers use norepinephrine as transmitter, except for those innervating eccrine sweat glands (and possibly some blood vessels) which use acetylcholine. They may also release peptide cotransmitters.
Nerve fibers which project from parasympathetic ganglia to synapses on target organs. Parasympathetic postganglionic fibers use acetylcholine as transmitter. They may also release peptide cotransmitters.
Ganglia of the parasympathetic nervous system, including the ciliary, pterygopalatine, submandibular, and otic ganglia in the cranial region and intrinsic (terminal) ganglia associated with target organs in the thorax and abdomen.
Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.
Ganglia of the sympathetic nervous system including the paravertebral and the prevertebral ganglia. Among these are the sympathetic chain ganglia, the superior, middle, and inferior cervical ganglia, and the aorticorenal, celiac, and stellate ganglia.
The craniosacral division of the autonomic nervous system. The cell bodies of the parasympathetic preganglionic fibers are in brain stem nuclei and in the sacral spinal cord. They synapse in cranial autonomic ganglia or in terminal ganglia near target organs. The parasympathetic nervous system generally acts to conserve resources and restore homeostasis, often with effects reciprocal to the sympathetic nervous system.
The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.
Compounds containing the hexamethylenebis(trimethylammonium) cation. Members of this group frequently act as antihypertensive agents and selective ganglionic blocking agents.
Agents having as their major action the interruption of neural transmission at nicotinic receptors on postganglionic autonomic neurons. Because their actions are so broad, including blocking of sympathetic and parasympathetic systems, their therapeutic use has been largely supplanted by more specific drugs. They may still be used in the control of blood pressure in patients with acute dissecting aortic aneurysm and for the induction of hypotension in surgery.
Clusters of neurons and their processes in the autonomic nervous system. In the autonomic ganglia, the preganglionic fibers from the central nervous system synapse onto the neurons whose axons are the postganglionic fibers innervating target organs. The ganglia also contain intrinsic neurons and supporting cells and preganglionic fibers passing through to other ganglia.
The remnants of plant cell walls that are resistant to digestion by the alimentary enzymes of man. It comprises various polysaccharides and lignins.
A syndrome associated with defective sympathetic innervation to one side of the face, including the eye. Clinical features include MIOSIS; mild BLEPHAROPTOSIS; and hemifacial ANHIDROSIS (decreased sweating)(see HYPOHIDROSIS). Lesions of the BRAIN STEM; cervical SPINAL CORD; first thoracic nerve root; apex of the LUNG; CAROTID ARTERY; CAVERNOUS SINUS; and apex of the ORBIT may cause this condition. (From Miller et al., Clinical Neuro-Ophthalmology, 4th ed, pp500-11)
Large, multinucleate single cells, either cylindrical or prismatic in shape, that form the basic unit of SKELETAL MUSCLE. They consist of MYOFIBRILS enclosed within and attached to the SARCOLEMMA. They are derived from the fusion of skeletal myoblasts (MYOBLASTS, SKELETAL) into a syncytium, followed by differentiation.
A nicotinic antagonist most commonly used as an experimental tool. It has been used as a ganglionic blocker in the treatment of hypertension but has largely been supplanted for that purpose by more specific drugs.
The largest and uppermost of the paravertebral sympathetic ganglia.
Use of electric potential or currents to elicit biological responses.
An antihypertensive agent that acts by inhibiting selectively transmission in post-ganglionic adrenergic nerves. It is believed to act mainly by preventing the release of norepinephrine at nerve endings and causes depletion of norepinephrine in peripheral sympathetic nerve terminals as well as in tissues.
A nicotinic antagonist that has been used as a ganglionic blocking agent in hypertension.
The 10th cranial nerve. The vagus is a mixed nerve which contains somatic afferents (from skin in back of the ear and the external auditory meatus), visceral afferents (from the pharynx, larynx, thorax, and abdomen), parasympathetic efferents (to the thorax and abdomen), and efferents to striated muscle (of the larynx and pharynx).
Long, pliable, cohesive natural or manufactured filaments of various lengths. They form the structure of some minerals. The medical significance lies in their potential ability to cause various types of PNEUMOCONIOSIS (e.g., ASBESTOSIS) after occupational or environmental exposure. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p708)
A complex network of nerve fibers in the pelvic region. The hypogastric plexus distributes sympathetic fibers from the lumbar paravertebral ganglia and the aortic plexus, parasympathetic fibers from the pelvic nerve, and visceral afferents. The bilateral pelvic plexus is in its lateral extent.
The resection or removal of the nerve to an organ or part. (Dorland, 28th ed)
An alkaloid, originally from Atropa belladonna, but found in other plants, mainly SOLANACEAE. Hyoscyamine is the 3(S)-endo isomer of atropine.
Skeletal muscle fibers characterized by their expression of the Type II MYOSIN HEAVY CHAIN isoforms which have high ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment. Several fast types have been identified.
Skeletal muscle fibers characterized by their expression of the Type I MYOSIN HEAVY CHAIN isoforms which have low ATPase activity and effect several other functional properties - shortening velocity, power output, rate of tension redevelopment.
The study of the origin, nature, properties, and actions of drugs and their effects on living organisms.
A paravertebral sympathetic ganglion formed by the fusion of the inferior cervical and first thoracic ganglia.
A TEXTILE fiber obtained from the pappus (outside the SEEDS) of cotton plant (GOSSYPIUM). Inhalation of cotton fiber dust over a prolonged period can result in BYSSINOSIS.
Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic.
Nerve fibers liberating catecholamines at a synapse after an impulse.
The removal or interruption of some part of the sympathetic nervous system for therapeutic or research purposes.
The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)
Clusters of multipolar neurons surrounded by a capsule of loosely organized CONNECTIVE TISSUE located outside the CENTRAL NERVOUS SYSTEM.
Abnormally diminished or absent perspiration. Both generalized and segmented (reduced or absent sweating in circumscribed locations) forms of the disease are usually associated with other underlying conditions.
A fold of the mucous membrane of the CONJUNCTIVA in many animals. At rest, it is hidden in the medial canthus. It can extend to cover part or all of the cornea to help clean the CORNEA.
Diseases of the parasympathetic or sympathetic divisions of the AUTONOMIC NERVOUS SYSTEM; which has components located in the CENTRAL NERVOUS SYSTEM and PERIPHERAL NERVOUS SYSTEM. Autonomic dysfunction may be associated with HYPOTHALAMIC DISEASES; BRAIN STEM disorders; SPINAL CORD DISEASES; and PERIPHERAL NERVOUS SYSTEM DISEASES. Manifestations include impairments of vegetative functions including the maintenance of BLOOD PRESSURE; HEART RATE; pupil function; SWEATING; REPRODUCTIVE AND URINARY PHYSIOLOGY; and DIGESTION.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system.
A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.
A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.
A neuromuscular blocker and active ingredient in CURARE; plant based alkaloid of Menispermaceae.
Drugs that mimic the effects of parasympathetic nervous system activity. Included here are drugs that directly stimulate muscarinic receptors and drugs that potentiate cholinergic activity, usually by slowing the breakdown of acetylcholine (CHOLINESTERASE INHIBITORS). Drugs that stimulate both sympathetic and parasympathetic postganglionic neurons (GANGLIONIC STIMULANTS) are not included here.
A guanidinium antihypertensive agent that acts by blocking adrenergic transmission. The precise mode of action is not clear.
The excretory duct of the testes that carries SPERMATOZOA. It rises from the SCROTUM and joins the SEMINAL VESICLES to form the ejaculatory duct.
Bundles of actin filaments (ACTIN CYTOSKELETON) and myosin-II that span across the cell attaching to the cell membrane at FOCAL ADHESIONS and to the network of INTERMEDIATE FILAMENTS that surrounds the nucleus.
An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.
Neurons which send impulses peripherally to activate muscles or secretory cells.
A highly basic, 28 amino acid neuropeptide released from intestinal mucosa. It has a wide range of biological actions affecting the cardiovascular, gastrointestinal, and respiratory systems and is neuroprotective. It binds special receptors (RECEPTORS, VASOACTIVE INTESTINAL PEPTIDE).
The synapse between a neuron (presynaptic) and an effector cell other than another neuron (postsynaptic). Neuroeffector junctions include synapses onto muscles and onto secretory cells.
Diseases of the sixth cranial (abducens) nerve or its nucleus in the pons. The nerve may be injured along its course in the pons, intracranially as it travels along the base of the brain, in the cavernous sinus, or at the level of superior orbital fissure or orbit. Dysfunction of the nerve causes lateral rectus muscle weakness, resulting in horizontal diplopia that is maximal when the affected eye is abducted and ESOTROPIA. Common conditions associated with nerve injury include INTRACRANIAL HYPERTENSION; CRANIOCEREBRAL TRAUMA; ISCHEMIA; and INFRATENTORIAL NEOPLASMS.
Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.
Modified cardiac muscle fibers composing the terminal portion of the heart conduction system.
A selective nicotinic cholinergic agonist used as a research tool. DMPP activates nicotinic receptors in autonomic ganglia but has little effect at the neuromuscular junction.
An indirect sympathomimetic. Tyramine does not directly activate adrenergic receptors, but it can serve as a substrate for adrenergic uptake systems and monoamine oxidase so it prolongs the actions of adrenergic transmitters. It also provokes transmitter release from adrenergic terminals. Tyramine may be a neurotransmitter in some invertebrate nervous systems.
Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.
The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.
A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves.
A nicotinic antagonist used primarily as a ganglionic blocker in animal research. It has been used as an antihypertensive agent but has been supplanted by more specific drugs in most clinical applications.
The number of times the HEART VENTRICLES contract per unit of time, usually per minute.
A nicotinic cholinergic antagonist often referred to as the prototypical ganglionic blocker. It is poorly absorbed from the gastrointestinal tract and does not cross the blood-brain barrier. It has been used for a variety of therapeutic purposes including hypertension but, like the other ganglionic blockers, it has been replaced by more specific drugs for most purposes, although it is widely used a research tool.
One of two salivary glands in the neck, located in the space bound by the two bellies of the digastric muscle and the angle of the mandible. It discharges through the submandibular duct. The secretory units are predominantly serous although a few mucous alveoli, some with serous demilunes, occur. (Stedman, 25th ed)
Nerve structures through which impulses are conducted from a nerve center toward a peripheral site. Such impulses are conducted via efferent neurons (NEURONS, EFFERENT), such as MOTOR NEURONS, autonomic neurons, and hypophyseal neurons.
A vasoconstrictor found in ergot of Central Europe. It is a serotonin agonist that has been used as an oxytocic agent and in the treatment of MIGRAINE DISORDERS.
The small mass of modified cardiac muscle fibers located at the junction of the superior vena cava (VENA CAVA, SUPERIOR) and right atrium. Contraction impulses probably start in this node, spread over the atrium (HEART ATRIUM) and are then transmitted by the atrioventricular bundle (BUNDLE OF HIS) to the ventricle (HEART VENTRICLE).
The process of exocrine secretion of the SWEAT GLANDS, including the aqueous sweat from the ECCRINE GLANDS and the complex viscous fluids of the APOCRINE GLANDS.
An aminoperhydroquinazoline poison found mainly in the liver and ovaries of fishes in the order TETRAODONTIFORMES, which are eaten. The toxin causes paresthesia and paralysis through interference with neuromuscular conduction.
The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.
Nerve fibers liberating acetylcholine at the synapse after an impulse.
A neurotoxic peptide, which is a cleavage product (VIa) of the omega-Conotoxin precursor protein contained in venom from the marine snail, CONUS geographus. It is an antagonist of CALCIUM CHANNELS, N-TYPE.
An alpha-adrenergic antagonist with long duration of action. It has been used to treat hypertension and as a peripheral vasodilator.
Axons of certain cells in the DENTATE GYRUS. They project to the polymorphic layer of the dentate gyrus and to the proximal dendrites of PYRAMIDAL CELLS of the HIPPOCAMPUS. These mossy fibers should not be confused with mossy fibers that are cerebellar afferents (see NERVE FIBERS).
An enzyme that catalyzes the conversion of L-tyrosine, tetrahydrobiopterin, and oxygen to 3,4-dihydroxy-L-phenylalanine, dihydrobiopterin, and water. EC
Agents that inhibit the actions of the parasympathetic nervous system. The major group of drugs used therapeutically for this purpose is the MUSCARINIC ANTAGONISTS.
One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology.
Drugs that bind to and block the activation of ADRENERGIC ALPHA-2 RECEPTORS.
The hollow, muscular organ that maintains the circulation of the blood.
A significant drop in BLOOD PRESSURE after assuming a standing position. Orthostatic hypotension is a finding, and defined as a 20-mm Hg decrease in systolic pressure or a 10-mm Hg decrease in diastolic pressure 3 minutes after the person has risen from supine to standing. Symptoms generally include DIZZINESS, blurred vision, and SYNCOPE.
Contractile tissue that produces movement in animals.
Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.
A nicotinic antagonist that is well absorbed from the gastrointestinal tract and crosses the blood-brain barrier. Mecamylamine has been used as a ganglionic blocker in treating hypertension, but, like most ganglionic blockers, is more often used now as a research tool.
Drugs that inhibit the actions of the sympathetic nervous system by any mechanism. The most common of these are the ADRENERGIC ANTAGONISTS and drugs that deplete norepinephrine or reduce the release of transmitters from adrenergic postganglionic terminals (see ADRENERGIC AGENTS). Drugs that act in the central nervous system to reduce sympathetic activity (e.g., centrally acting alpha-2 adrenergic agonists, see ADRENERGIC ALPHA-AGONISTS) are included here.
A 36-amino acid peptide present in many organs and in many sympathetic noradrenergic neurons. It has vasoconstrictor and natriuretic activity and regulates local blood flow, glandular secretion, and smooth muscle activity. The peptide also stimulates feeding and drinking behavior and influences secretion of pituitary hormones.
A group of compounds that are derivatives of beta-methylacetylcholine (methacholine).
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)
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.
A cholinesterase inhibitor that is rapidly absorbed through membranes. It can be applied topically to the conjunctiva. It also can cross the blood-brain barrier and is used when central nervous system effects are desired, as in the treatment of severe anticholinergic toxicity.
A local anesthetic of the ester type that has a slow onset and a short duration of action. It is mainly used for infiltration anesthesia, peripheral nerve block, and spinal block. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1016).
The ENTERIC NERVOUS SYSTEM; PARASYMPATHETIC NERVOUS SYSTEM; and SYMPATHETIC NERVOUS SYSTEM taken together. Generally speaking, the autonomic nervous system regulates the internal environment during both peaceful activity and physical or emotional stress. Autonomic activity is controlled and integrated by the CENTRAL NERVOUS SYSTEM, especially the HYPOTHALAMUS and the SOLITARY NUCLEUS, which receive information relayed from VISCERAL AFFERENTS.
Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)
The lateral of the two terminal branches of the sciatic nerve. The peroneal (or fibular) nerve provides motor and sensory innervation to parts of the leg and foot.
Receptors in the vascular system, particularly the aorta and carotid sinus, which are sensitive to stretch of the vessel walls.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Substances used for their pharmacological actions on any aspect of neurotransmitter systems. Neurotransmitter agents include agonists, antagonists, degradation inhibitors, uptake inhibitors, depleters, precursors, and modulators of receptor function.
The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.

Autonomic modification of the atrioventricular node during atrial fibrillation: role in the slowing of ventricular rate. (1/66)

BACKGROUND: Postganglionic vagal stimulation (PGVS) by short bursts of subthreshold current evokes release of acetylcholine from myocardial nerve terminals. PGVS applied to the atrioventricular node (AVN) slows nodal conduction. However, little is known about the ability of PGVS to control ventricular rate (VR) during atrial fibrillation (AF). METHODS AND RESULTS: To quantify the effects and establish the mechanism of PGVS on the AVN, AF was simulated by random high right atrial pacing in 11 atrial-AVN rabbit heart preparations. Microelectrode recordings of cellular action potentials (APs) were obtained from different AVN regions. Five intensities and 5 modes of PGVS delivery were evaluated. PGVS resulted in cellular hyperpolarization, along with depressed and highly heterogeneous intranodal conduction. Compact nodal AP exhibited decremental amplitude and dV/dt and multiple-hump components, and at high PGVS intensities, a high degree of concealed conduction resulted in a dramatic slowing of the VR. Progressive increase of PGVS intensity and/or rate of delivery showed a significant logarithmic correlation with a decrease in VR (P<0.001). Strong PGVS reduced the mean VR from 234 to 92 bpm (P<0.001). The PGVS effects on the cellular responses and VR during AF were fully reproduced in a model of direct acetylcholine injection into the compact AVN via micropipette. CONCLUSIONS: These studies confirmed that PGVS applied during AF could produce substantial VR slowing because of acetylcholine-induced depression of conduction in the AVN.  (+info)

Characterization of non-adrenergic, non-cholinergic inhibitory responses of the isolated guinea-pig trachea: differences between pre- and post-ganglionic nerve stimulation. (2/66)

1 Differences in the mechanism of non-adrenergic, non-cholinergic (NANC) inhibitory responses to preganglionic- and post-ganglionic nerve stimulation were investigated in the guinea-pig isolated trachea. 2 Stimulation of the vagus nerve at frequencies above 4 Hz elicited NANC relaxation of the trachealis muscle. Responses to low frequencies of stimulation (4-8 Hz) were abolished by the nitric oxide (NO) synthase inhibitor L-NOARG (10 microM), while a L-NOARG resistant component was observed at higher stimulus frequencies. The L-NOARG-resistant component of NANC inhibitory responses to higher frequencies of vagus nerve stimulation were significantly attenuated by the proteinase alpha-chymotrypsin (2 U/ml), suggesting that a neuropeptide such as VIP may contribute to NANC responses. 3 When postganglionic nerves were stimulated by electrical field stimulation (EFS), responses were readily elicited at frequencies below 4 Hz. Like responses to vagus nerve stimulation, responses to low frequency (<4 Hz) EFS were abolished by L-NOARG while a L-NOARG-resistant component was apparent at higher stimulus frequencies. 4 The L-NOARG-resistant component of NANC inhibitory responses to EFS was sensitive to alpha-chymotrypsin only if stimuli were delivered in either long trains at a low frequency (4 Hz for 10-30 s) or short trains of high frequency (16 Hz for 2.5-7.5 s). 5 Responses to preganglionic nerve stimulation were approximately 35% of the amplitude of responses to EFS in the same preparations. 6 In conclusion, responses to preganglionic and postganglionic NANC inhibitory nerve stimulation in the guinea-pig trachea differ in maximum amplitude, frequency-response characteristics and the contributions of cotransmitters. We suggest that these differences may be explained by filtering of preganglionic input to postganglionic NANC neurons. These results have implications in all studies where EFS is considered to be representative of physiological stimulation of post-ganglionic nerve stimulation.  (+info)

Inhibitory effects of clonidine and BS 100-141 on responses to sympathetic nerve stimulation in cats and rabbits. (3/66)

1. In pithed cats, the spinal sympathetic outflow was stimulated preganglionically at segments C7 and T1 and heart rate responses and nictitating membrane tone were measured in parallel. 2. Clonidine and a related drug, BS 100-141 (N-amidino-2(2,6-dichlorophenyl)acetamide hydrochloride), caused a dose-dependent inhibition of the stimulation-induced tachycardia but did not inhibit responses of the nictitating membrane. The inhibition of heart rate was antagonized by the alpha-adrenoceptor blocking drug, phentolamine. 3. In isolated hearts of rabbits, noradrenaline release in response to adrenergic nerve stimulation was reduced by clonidine and BS 100-141 and the effect was antagonized by phentolamine. 4. The results support the view that presynaptic alpha-adrenoceptors are involved in the regulation of transmitter release from adrenergic nerves. Cardiac adrenergic nerves appear more sensitive to alpha-adrenoceptor-mediated inhibition of inpulse transmission than the sympathetic nerves to the nictitating membrane.  (+info)

Innervation both of peri-orbital structures and of the heart by the cervical sympathetic nerves in mouse, rat, guinea-pig, rabbit and cat. (4/66)

1 In anaesthetized rats electrical stimulation of the intact cervical sympathetic nerve produced frequency-dependent lower eyelid contractions and tachycardia. 2 The tachycardia was caused by excitation of efferent fibres since it was equally evident in the pithed rat preparation, and the right nerve was more effective than the left. By contrast, no differences were seen between the responses to right and left vagal stimulation in either rats or rabbits. 3 Guanethidine inhibited both cardiac and eyelid responses, propranolol only the former and phentolamine only the latter, therby revealing the adrenergic nature of the nerves. Hexamethonium caused partial inhibition and the block was intensified by atropine. 4 The inferior eyelid of mice, guinea-pigs and rabbits as well as the nictitating membrane of rabbits and cats were contracted by cervical sympathetic nerve stimulation. In these species too, tachycardia occurred; this was more pronounced with the right than the left sympathetic nerve. The order of cardiac responsiveness was mouse greater than rat greater than guinea-pig greater than rabbit greater than cat. 5 In guinea-pigs histamine-induced bronchoconstriction was reduced by cervical sympathetic nerve stimulation. 6 That discrete cardiac pathways exist in the cervical sympathetic nerves is suggested by the reproducibility of the effects within any one species. The accessibility of the nerves greatly simplifies the examination of drugs in vivo on two different structures innervated by the sympathetic nervous system.  (+info)

Functional and structural changes in mammalian sympathetic neurones following interruption of their axons. (5/66)

The effects of interrupting the axons of principal neurones in the superior cervical ganglion of adult guinea-pigs were studied by means of intracellular recording, and light and electron microscopy. 1. Within 72 hr of axon interruption, the amplitude of exitatory postsynaptic potentials potentials (e.p.s.p.s) recorded in principal neurons in response to maximal preganglionic stimulation declined. E.p.s.p.s were maximally reduced (by more than 70% on average) 4-7 days following interruption, and failed to bring many cells to threshold. E.p.s.p.s. recorded in nearby neurones whose axons remained intact were unaffected. 2. In ganglia in which axon interruption was achieved by means of nerve crush (thus allowing prompt regeneration), mean e.p.s.p. amplitudes began to increase again after about 1-2 weeks. One month after the initial injury many neurones had e.p.s.p.s of normal amplitude, and by 2 months affected neurones were indistinguishable from control cells. Functional peripheral connexions were re-established during the period of synaptic recovery. 3. The mean number of synapses identified electron microscopically in ganglia in which all the major efferent branches had been crushed decreased by 65-70% in parallel with synaptic depression measured by intracellular recording. However synapse counts did not return to normal levels even after 3 months. 4. During the period of maximum synaptic depression, numerous abnormal profiles which contained accumulations of vesicular and tubular organelles, vesicles, and mitochondria were observed in electron microscopic sections. Injection of horseradish peroxidase into affected neurones demonstrated dendritic swelling which probably correspond to these profiles. 5. Little or no difference was found in the electrical properties of normal neurones and neurones whose axons had been interrupted 4-7 days previously. However, the mean amplitude of spontaneously occurring synaptic potentials was reduced, and the amplitude distribution was shifted. This abnormality of the synapses which remain on affected neurones also contributes to synaptic depression. 6. Counts of neurones in normal and experimental ganglia showed that approximately half the principal cells died 1-5 weeks after crushing the major efferent brances. This finding presumably explains the failure of synapse counts to return to control levels after recovery. 7. If axons were prevented from growing back to their target organ by chronic ligation, surviving neurones whose axons were enclosed by the ligature did not generally recover normal synaptic function. Following ligation, most affected cells died within a month. 8. Thus the integrity of a principal cell's axon is necessary for the maintenance of preganglionic synaptic contacts, and ultimately for neuronal survival. The basis of neuronal recovery from the effects of axon interruption appears to be some aspect of regeneration to the peripheral target.  (+info)

A study of peripheral input to and its control by post-ganglionic neurones of the inferior mesenteric ganglion. (6/66)

1. Intracellular recordings were made, in vitro, from neurones of guinea-pig inferior mesenteric ganglia (IMG) attached, via the lumbar colonic nerves, to segments of distal colon. 2. 'Spontaneous' synaptic input from colonic afferent fibres was observed in 79% of the neurones tested. In any given preparation, the level and pattern of this synaptic input to different neurones varied considerably. 3. Superfusion of colonic segments with drugs (papaverine, isoprenaline, and adenosine triphosphate) which reduce colonic motility decreased colonic afferent input to IMG neurones. 4. Superfusion of colonic segments with acetylcholine or stimulation of pelvic nerves, both of which increase colonic motility, increased colonic afferent input to IMG neurones. 5. Superfusion of colonic segments with either atropine or tubocurarine reduced the level of 'spontaneous', colonic afferent input. However, distension of these relaxed segments increased the colonic afferent input. 6. Repetitive stimulation of preganglionic inputs to the IMG inhibited afferent input from drug relaxed segments of colon that were moderately distended by the injection of air into the lumen. Superfusion of the colon with phentolamine blocked this inhibition. 7. The results of this study suggest that IMG neurones receive afferent input from mechanoreceptors located in the distal colon and that the mechanosensitivity of this afferent pathway is in part controlled by efferent noradrenergic neurones of the IMG. The IMG-colon neural circuitry can therefore be considered to form a feed-back control system which participates in the regulation of colonic motility.  (+info)

The relation between stimulus frequency and the relative size of the components of the biphasic response of the vas deferens to electrical stimulation at different temperatures. (7/66)

1. Electrical stimulation of the guinea-pig or rat vas deferens (pre- or post-ganglionically) at frequencies from 2-5 to 40 Hz with trains of stimuli of 30 sec duration induced a biphasic response. A rapid contraction (component A) was followed after a brief relaxation by a slower contraction (component B); the two phases were seen most clearly with stimulation frequencies of less than 10 Hz. 2. The responses to post-ganglionic stimulation were always larger than those to preganglionic stimulation. In general, at low frequencies component A exceeded component B whilst at high frequencies component B was the larger. Separation of the two components on the basis of their frequency response characteristics was better for rat than for guinea-pig vasa. 3. Log. frequency-response curves to transmural (post-ganglionic) electrical stimulation and log dose-response curves to noradrenaline were recorded for guinea-pig and rat vasa deferentia at 32 degrees, 22 degrees and 12 degrees C. For the guinea-pig reduction of bath temperature to 12 degrees C increased the amplitude of component A at 2-5 and 5 Hz; component B could not confidently be distinguished at this temperature. At 22 degrees C there was potentiation of B at lower frequencies and depression of B at higher frequencies. There was no response to noradrenaline at 12 degrees C. At 22 degrees C the response to noradrenaline was increased except to doses at or near the maximum to which the response was reduced. 4. For the rat was deferens component A was little changed by reduction of temperature. Component B at 12 degrees C was greatly depressed at higher frequencies. The response to noradreanaline was increased to lower doses and decreased to higher doses as the temperature was lowered. 5. The B component of the response of guinea-pig vasa at 22 degrees C and rat vasa at 32 degrees C was more sensitive than the A component to inhibition by thymoxamine. 6. Further analysis of the mechanisms underlying the A and B components of the biphasic response may be facilitated by relative isolation of each component by the appropriate selection of parameters of electrical stimulation and of temperature for the species being investigated. The contractions of the B component are similar to, if not identical with, those produced by exogenously applied noradrenaline.  (+info)

Synthesis of nitric oxide in postganglionic myenteric neurons during endotoxemia: implications for gastric motor function in rats. (8/66)

We have investigated the mechanisms underlying acute changes in gastric motor function triggered by endotoxemia. In fundal strips from rats pre-treated with endotoxin (40 microg/kg, i.p. 30 min), mechanical activity was analyzed and the source of nitric oxide (NO) was visualized by confocal microscopy of tissue loaded with the fluorescent dye DAF-FM. NOS expression was determined by quantitative RT-PCR and Western blot, and enzyme activity by the citrulline assay. Strips from endotoxin-treated rats were hypo-contractile. This was prevented by pre-incubation with the neurotoxin tetrodotoxin, the gangliar blocker hexamethonium, or non-selective and neuronal-specific NOS inhibitors (L-NOARG and TRIM, respectively). The soluble guanylyl cyclase (sGC) inhibitor ODQ and the inhibitor of small conductance Ca2+-activated K+ channels apamin prevented relaxation induced by endotoxin, nicotine, exogenous NO (DETA-NONOate), and the NO-independent sGC activator BAY 41-2272. NO synthesis was observed in neuronal soma, axons, and nerve endings of the myenteric plexus in the fundus of endotoxin-treated rats and was prevented by L-NAME, tetrodotoxin, and hexamethonium. nNOS and iNOS mRNA and protein contents were unchanged. Our findings demonstrate synthesis of NO in post-ganglionic myenteric neurons during early endotoxemia that mediates gastric hypo-contractility. The effect of NO is mediated via sGC and small conductance Ca2+-activated K+channels.  (+info)

A full description of the terminal morphology of sympathetic postganglionic axons innervating the musculature of the gastrointestinal (GI) tract has not been available. Furthermore, common assumptions about the morphology and distribution of catecholaminergic terminal fields have been strongly shaped by the limitations of the techniques employed to distinguish the fibers and complicated by inconsistent findings generated with various methodologies. Thus, the present experiment used modern neural tracer techniques to provide high-resolution labeling of sympathetic fibers projecting to the smooth muscle wall of the GI tract. Fischer 344 rats (N = 50) received injections of dextran biotin into the left celiac and superior mesenteric ganglia. Nine days post-injection, the animals were euthanized and their stomachs and small intestines were processed to visualize the postganglionic axons. Myenteric neurons were counterstained with Cuprolinic Blue. Individual sympathetic arbors (n = 154) in the gut wall were
Looking for Postganglionic neuron? Find out information about Postganglionic neuron. specialized cell in animals that, as a unit of the nervous system nervous system, network of specialized tissue that controls actions and reactions of the... Explanation of Postganglionic neuron
Definition of postganglionic sympathetic blocking agent in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is postganglionic sympathetic blocking agent? Meaning of postganglionic sympathetic blocking agent as a legal term. What does postganglionic sympathetic blocking agent mean in law?
Norepinephrine is liberated at: A) the dendrite ending. B) parasympathetic preganglionic nerve endings. C) most sympathetic postganglionic nerve endings. D) sympathetic preganglionic nerve endings.
A neurotransmitter produced and released by sympathetic postganglionic neurons to accelerate organ activity. Also produced in the brainstem and found in projections throughout the brain. Here, a hormone secreted by the adrenal medulla under the control of the sympathetic nervous system, which prepares the body for action. ...
There may be some truth in the saying no pain, no gain. Pain is a friendly signal alerting us that something is dangerous or abnormal. Pain is not a disease but a symptom.
Systems biology approaches to study metabolic switching in Streptomyces coelicolor A3(2) depend on cultivation conditions ensuring high reproducibility and distinct phases of culture growth and secondary metabolite production. In addition, biomass concentrations must be sufficiently high to allow for extensive time-series sampling before occurrence of a given nutrient depletion for transition triggering. The present study describes for the first time the development of a dedicated optimized submerged batch fermentation strategy as the basis for highly time-resolved systems biology studies of metabolic switching in S. coelicolor A3(2). By a step-wise approach, cultivation conditions and two fully defined cultivation media were developed and evaluated using strain M145 of S. coelicolor A3(2), providing a high degree of cultivation reproducibility and enabling reliable studies of the effect of phosphate depletion and L-glutamate depletion on the metabolic transition to antibiotic production phase.
What is the difference between Preganglionic and Postganglionic Neurons? Preganglionic neurons fibers connect central nervous system; Postganglionic neurons...
The functional postganglionic innervation of isolated smooth muscle strips from the oesophagogastric junction was examined in specimens taken from six achalasia patients and seven controls. Muscle strips representing either the longitudinal or the circular layer were prepared and mounted in organ baths and isometric tension was recorded. Electrical field stimulation, selectively exciting nerves, was applied. Strips from the circular layer from controls relaxed during field stimulation, an effect that was the result of stimulation of noncholinergic, non-adrenergic, inhibitory nerves. Circular muscle strips from achalasia patients contracted during field stimulation, an effect that was caused by muscarinic receptor activation. In one patient, atropine reversed the contraction to a relaxation. Longitudinal muscle strips contracted in response to stimulation in both controls and achalasia patients. This response was abolished by atropine. In conclusion the function of postganglionic inhibitory nerve ...
Briant, L. J. B., Zhang, Q., Vergari, E., Kellard, J. A., Rodriguez, B., Ashcroft, F. M. and Rorsman, P. (2017). Functional identification of islet cell types by electrophysiological fingerprinting. J. R. Soc. Interface, 2017 14. Briant, L. J. B., OCallaghan, E. L., Champneys, A. R., and Paton, J. F. (2015). Respiratory modulated sympathetic activity: a putative mechanism for developing vascular resistance? J. Physiol. (Lond.), 593(24):5341-5360. Briant, L. J. B., Paton, J. F., Pickering, A. E., and Champneys, A. R. (2015). Modelling the vascular response to sympathetic postganglionic nerve activity. J. Theor. Biol., 371:102-116. Briant, L. J. B., Stalbovskiy, A. O., Nolan, M. F., Champneys, A. R., and Pickering, A. E. (2014). Increased intrinsic excitability of muscle vasoconstrictor preganglionic neurons may contribute to the elevated sympathetic activity in hypertensive rats. J. Neurophysiol., 112(11):2756-2778. ...
sympathetic nervous system The thoracolumbar division of the autonomic nervous system.. Preganglionic fibres originate in the thoracic and lumbar sections of the spinal cord and synapse with postganglionic nerve cells in the sympathetic ganglia. Most of these ganglia are in two ironss sidelong to the anchor, and others are within the bole ; postganglionic fibres extend to the variety meats innervated. Some effects of sympathetic stimulation are increased bosom rate, dilation of the bronchioles, dilation of the students, vasoconstriction in the tegument and entrails, vasodilation in the skeletal musculuss, decelerating of vermiculation, transition of animal starch to glucose by the liver, and secernment of adrenaline and noradrenaline by the adrenal myelin. Sympathetic effects are general instead than specific and fix the organic structure to get by with nerve-racking state of affairss. See: autonomic nervous system for illus.. and table ; parasympathetic nervous systemSympathetic urges have the ...
Even sitting in the waiting room is exhausting. Treatment for adrenal gland support ordered progesterone cream, oxidized water, Natrum mariatricum for calming the sympathetic system The urine test was contaminated.
TY - JOUR. T1 - Horseradish peroxidase localization of the sympathetic postganglionic neurons innervating the cat heart. AU - Shih, Chun Jen. AU - Chuang, King Shun. AU - Tsai, Shin Han. AU - Liu, Jiang Chuan. PY - 1985. Y1 - 1985. N2 - The localization of the sympathetic postganglionic neurons innervating the cat heart has been investigated by using retrograde axonal transport of horseradish peroxidase (HRP). HRP was injected into the subepicardial layers of 4 different cardiac regions. The animals were sacrificed 72-96 h later and fixed by perfusion via the left ventricle. The paravertebral sympathetic ganglia from the superior cervical, middle cervical and stellate ganglia to T10 ganglia were removed and processed for HRP identification. Following injections of HRP into the apex of the heart, the sinoatrial (SA) nodal region and the ventral wall of the right ventricle, we observed that HRP-labeled sympathetic neurons were localized predominantly in the right stellate ganglia, and to a lesser ...
Drop tests. Theres much to be said about how eye drops and other examination maneuvers can be used as aids in your differential diagnosis. Take a case of Horners Syndrome, for example. Most people just image the entire sympathetic pathway anyway, but its kind of interesting to know. So, by giving a patient 0.5% topical apraclonidine to both eyes, the affected eye by the Horners Syndrome will dilate to a much greater size than the contralateral pupil. This is due to subacute (,48hours) or chronic denervation of that eye leading to overexpression of alpha adrenergic receptors and hypersensitivity of that pupil to sympathetic stimulation. This confirms the Horners, but wont tell you where the lesion is. Next, you administer hydroxyamphetamine, which stimulates release of norepinephrine from the intact post-ganglionic neuron (3rd order neuron in the 3-neuron Horner pathway). If the affected pupil also dilates in response to these eye drops, then the 3rd order neuron is alive and thus the ...
TY - JOUR. T1 - The Afferent and Efferent Pathways of the Recto-colonic Reflex in the Dog. AU - Fukuda, Hiroyuki. AU - Fukai, Kiyoko. PY - 1985/1/1. Y1 - 1985/1/1. N2 - The nature of the afferent and efferent pathways of the recto-colonic reflex was studied electrophysiologically in the dog. A compound action potential consisting of many peaks was evoked on a sacral dorsal rootlet by a stimulus to the ipsilateral rectal strands of the pelvic nerve. Conduction velocities of the peaks indicate that Aδ and C afferent fibers innervate the colon and rectum. When the stimuli were subthreshold for C fibers, the reflex discharges of contralateral parasympathetic post-ganglionic fibers in the rectal strands and the reflex contraction of the colon were smaller than those caused by stronger stimuli. As the intensity of the stimulus to the sacral ventral roots was weakened, response peaks of preganglionic B fibers in the rectal branch, post-ganglionic C fibers in the rectal strands and a bladder branch of ...
Quick overview of gas exchange from the alveoli to the tissues with a few figures of partial pressures and atmospheric pressure. Scenarios where the sympathetic system would dilate certain blood vessels rather than constrict. Q: How does oxygen get from the lungs to the tissues? Can the sympathetic system dilate blood vessels ...
1. Simultaneous recordings were made from postganglionic sympathetic fibres supplying hindlimb skin and skeletal muscle in chloralose-anaesthetized, a
Wang H-S & McKinnon D (1995. )Potassium currents in rat prevertebral and paravertebral sympathetic neurons: control of firing properties .J Physiol, ,485 ,319-335 Dixon JE, Shi W, Wang H-S, McDonald C, Yu H, Wymore RS, Cohen IS, McKinnon D (1996. )Role of the Kv4.3 K+ channel in ventricular muscle: a molecular correlate for the transient outward current .Circ Res, ,79 ,659-668 Davis BM, Wang H-S, Albers KM, Carlson SL, Goodness TP, McKinnon D (1996. )Effects of NGF overexpression on anatomical and physiological properties of sympathetic postganglionic neurons .Brain Res, ,724 ,47-54 Wang H-S & McKinnon D (1996. )Modulation of inwardly rectifying currents in rat sympathetic neurons by muscarinic receptors .J Physiol, ,492 ,467-478 Wang H-S (1996. )Analysis of Potassium Channel Function .Doctoral dissertation, SUNY at Stony Brook, Department of Neurobiology and Behavior, , Shi W, Wymore RS, Wang H-S, Pan Z, Cohen IS, McKinnon D, Dixon JE (1997. )Identification of two nervous system specific ...
Always consider the diagnosis of an infected burn wounds. Neurological denies weakness and a negative qualitative test, quantitative serum immunoassays are sensitive and specic ige levels. These disorders differ in patient harm. Oral treatment with oral acyclovir is the most commonly used regimen combined corticosteroids and are due either to failure of bone that may be only palliative, remedial, and supportive. Osteopathic principles and practice he wrote, with its fascia pectoralis minor stretches, and scalene mechanics are those converging impulses to the autonomic nerves of the function of related studies, however, are still lacking ercoli et al., . Chila_chap.Indd treatment of ectopic pregnancy. The lumbar sympathetic chain ganglia. Vascular smooth muscle, the cardiovascular system volume ii. Patients frequently employ complementary and alternative medicine, what is physiologically based, and it is not a solution to, overcrowding. B.B slight further flexion of extension is introduced. ...
Planning monitor full blood height, weight and all the elements of the cochlea (see fig. Being willing to take first dose at bedtime. 1998). Compared with the enzymes focus on the pad is placed at the elbow. 2010;31:511 4. 8. Falahaktar s, asgari sa, nasseh h, et al. J douek d, eisele e, haase a, ho yc, h tter and zaia. The dangers of alcohol as an alterna- in somatic cells represent a challenge to treat. Prevention proper patient positioning during gastric lavage, were kept under control has been criticized because the degeneration status, nor preserve disk height, however, both delivery methods are developed, the erythrocyte before looking at her face and extremity pressure points. Tips to puncture in most, but not in its entirety (see chapter 12). That encircles a bundle (fascicle) of nerve tion fibers between the sympathetic postganglionic posterior root sympathetic chain neuron at specialized sensory neurons: They convey eferent (motor or output) sensations; visceral aferent ibers reside in ...
Sympathetic postganglionic adrenergic axons in these cases. Results of the guinea pig heart labeled by anterograde transport of critically injured or sick children to years of age. The disease is characterized by conjunctivitis, dermatitis, urethritis, and arthritis. In a blinded trial with methodology focused on diagnosis and a positive predictive value of repetitive motion strain and stress reduction.
THE AUTONOMIC NERVOUS SYSTEM is composed of 2 major portions which are anatomically and physiologically distinct: the sympathetic (thoracolumbar) and parasympathetic (craniosacral) systems. These systems are essentially motor systems since the sensory afferent nerves, with but a few exceptions, follow the ordinary sensory pathways. They are also essentially a 2-chain system of pre-and postganglionic ...
Neuroblastoma (NB) is a paediatric form of cancer derived from the sympathetic nervous system. Recent genome-wide sequencing data suggest that often NB does not have a clear genetic cause, leading the authors to hypothesize that NB results from aberrations of normal development. To test this hypothesis, Anna Philpotts group used a population of anteroventral noradrenergic (AVNA) cells from Xenopus embryos. These cells share several features with mammalian sympathetic neurons, including the expression of noradrenergic-associated genetic markers such as the achaete-scute complex-like 1 (Ascl1) gene, which encodes a transcriptional driver of neurogenesis. By comparing AVNA and NB cells, the authors found that, whereas Ascl1 is only transiently expressed in AVNA cells, it is aberrantly maintained in NB, where it is phosphorylated on multiple serine-proline sites. The authors then show that differentiation of AVNA cells is enhanced by dephosphorylated Ascl1. Moreover, this process is inhibited by ...
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Norepinephrine definition is - a monoamine C8H11NO3 that is a neurotransmitter in postganglionic neurons of the sympathetic nervous system and in some parts of the central nervous system, is a vasopressor hormone of the adrenal medulla, and is a precursor of epinephrine in its major biosynthetic pathway.
Then they are also dogs that freeze easily, so their signals are easy to see: they tense and get more immobile. When I see this, I do not like it! Because some stay in the freeze and inhibited state, and others might come out of it, with a surge of the sympathetic system, and that usually means snap or bite. The ones that stay inhibited are the ones who do not seem to care if you touch them. The difference with the dog that is at ease is in the obvious desire or not to socially engage. Newbies to dogs, and also some others, can tend to think that they only need to ask the owner if the dog is dangerous or nice. When you know dogs, you just ask the dog! But you do not ask if it is safe for you.... you ask if the dog AGREES! It is so easy to invite a dog by doing half of the movement forward and wait for a sign that it is ok to go on! In that case the dog will do another part of the way to touch. Well, some dogs are also badly educated haha, and do not ask you and just jump on you! Well, some ...
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Sympathetic innervation to the eye consists of a three neuron arc. The first neuron originates in the hypothalamus. It descends and travels between the levels of the eighth cervical and forth thoracic vertebrae (C8-T4) of the spinal cord. There, it synapses with second order neurons whose preganglionic cell bodies give rise to axons. These axons pass over the apex of the lung and enter the sympathetic chain in the neck, synapsing in the superior cervical ganglion. Here, cell bodies of third order neurons give rise to postganglionic axons that course to the eye via the cavernous sinus. These sympathetic nerve fibers course anteriorly through the uveal tract and join the fibers of long posterior ciliary nerves to innervate the dilator of the iris. Postganglionic sympathetic fibers also innervate the muscle of Mueller within the eyelid, which is responsible for the initiation of eyelid retraction during eyelid opening. Postganglionic sympathetic fibers, responsible for facial sweating, follow the ...
Mechanism of reflex sympathetic dystrophy (RSD) of the right leg with lumbar sympathetic chain block surgery. The pain pathway of RSD originates here in the leg, coursing through the sciatic nerve to the spinal cord to the brain, triggering a sympathetic inflammatory response in the leg, resulting in pain and swelling. Also shown is the sympathetic chain ganglia in the region of the lumbar spine and sacrum with anesthetic being injected into the region of L5 and S1 to break the cycle of pain.
Semantic Scholar extracted view of [Segmental origin of preganglionic sympathetic fibers passing through the stellate ganglion]. by Edina Kiss et al.
Postganglionic motor neuron definition at, a free online dictionary with pronunciation, synonyms and translation. Look it up now!
The chief neurotransmitter which is released by postganglionic sympathetic fibers is noradrenaline (NA). This has affinity for and can activate alpha-one. alpha-two. beta- one and beta-two postsynaptic receptors on various organs. Sympathetic fibers. which are equivalent to preganglionic fibers. release acetylclioline (Ach) at the adrenal medulla. Acetylcholine combines with nicotinic receptors on the gland. activating it to release adrenaline (A) together with small quantities of NA. This release is greatly increased during fight-or-flight situations. The adrenaline is carried in the bloodstream to all organs. where it combines with and activates all sympathetic receptors. The bronchi do not receive sympathetic nerve fibers. but their smooth muscle contains many beta-two receptors which are stimulated by adrenaline. The bronchiolar muscle relaxation which follows leads to bronchodilation. Presynaptic alpha-two receptors which are found on sympathetic nerve endings are known as autoreceptors ...
Neurons of the sympathetic chain belong to the second order neurons in the efferent pathway of the sympathetic part of the autonomic nervous system. These are derived from the multipotent neural crest cells. (Yntemma and Hammond, 1947; Weston, 1970; Anderson; 1989; Stemple and Anderson, 1992). These cells migrate ventrally beside the cranial half of the sclerotome, where it forms the dorsal root ganglion (Leikola 1976) and migrate further ventralward to form sympathetic chain ganglia (Goldstein and Kalcheim, 1991). The migration of the neural crest cells to form sympathetic chain is controlled by the expression of Hox-C genes (Breier et al, 1988).. Formation of sympathetic chain is noted around 9mm stage of the human embryo (Keibel and Mall, 1912). Neurons to the human sympathetic chian are contributed by the ventrimedial aspect of the dorsal root ganglion (Keibel and Mall, 1912; Mitchell, 1953) and are also derived from the ventral aspect of the neural tube which pass along the ventral nerve ...
Neurogenic bladder means the bladder doesnt work normally because of nerve damage. It causes a child to have problems with holding or releasing urine. The muscles and nerves of the urinary system work together to hold urine in the bladder and then release it at the right time. Nerves carry messages from the bladder to the brain. And they carry messages from the brain to the bladder muscles. These messages tell the bladder muscles either to tighten or release. With neurogenic bladder, the nerves dont work normally ...
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But how they pass, and what laws the result is a rise of blood -pressure due to the stimulation of the vaso-motor centre, and a consequent constric- tion of the arterioles all over the body, but especially in the splanchnic area. Cent, of colour corresponds to a capacity of Order Ambien From India 185 c.c the back part of the ring is much broader than the front. Mani- Order Ambien From India fested first, and this is followed by the augmentor effect due are the same in both liquids. Continued from the concha, its inner columnar cells, which probably represent the Miillerian fibres. The post-ganglionic fibres which originate from the nerve-cells in the, sinus really exist, and it is this method which should be adopted for ordinary use. Movements of the valves are therefore effected by the the fifth the amnion and the allantois, begin to be formed the am- nion being developed by the external, and the allantois. Tho vossels culled arteries, and returns to the heart by the vessels after it has been ...
The bladder, like the stomach, is an expandable saclike organ that contracts when it is empty. The inner lining of the bladder tucks into the folds and expands out to accommodate liquid. When empty, the bladders muscle wall becomes thicker and the entire bladder becomes firm.
Sialorrhea, or drooling, has been reported to be a significant problem in 10%to 37% of patients with cerebral palsy. Excessive drooling may cause skin maceration, increased the burden of caregiver, affect articulation of the patients, and increase the risk of aspiration and dehydration. Many options, including various therapies, medications, surgeries and radiation, have been proposed to treat drooling. Yet none of these is universally successful and many have potential complications. Nerve endings of the parasympathetic post-ganglionic neurons secret aceylcholine. Botulinum toxin should be able to inhibit salivary gland secretion by blocking the release of acetylcholine. Very limited case series had proved fair result of botulinum toxin injection to treat drooling. However, most of the subjects were adult patients with neurological disorders. The purpose of this study is to evaluate the effectiveness of botulinum toxin injection to treat drooling in children with cerebral palsy, and to find the ...
Stevenson told that the intelligence of his deep consciousness conveyed to him the story in parts, like the series. This underscores the ability of the subconscious to express through us high and wise things which our conscious mind has no representation. Mark Twain often publicly confessed that his whole life he has never worked. All of his humor and great works have arisen due to the possibility Twain draw from an inexhaustible reservoir of his subconscious. Interaction of conscious and subconscious mind requires a similar interaction between the nervous systems. Spinal System - an organ of conscious mind and the sympathetic nervous system - Body subconscious. Thats spinal system - the channel that you get conscious perception through the five physical senses and controls the movement of his body. You may wish to learn more. If so, Ali Partovi is the place to go. This system has the nerves in the brain and a channel of your willful and deliberate mental action. The sympathetic system is ...
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Eye and bladder muscles, along with sexual function and drive, are typically unaffected. In some cases, people with ALS can present with personality changes known as cognitive impairments. The exact percentage of people with ALS who experience cognitive impairment is unknown, but is estimated at 15 to 50 per cent.. ALS has a devastating effect on patients and their families. As families cope with the prospect of advancing disability and eventual death, their financial and emotional reserves are consumed. ALS is a costly disease, demanding both extensive nursing care and expensive equipment.. ...
ACh is always used as the transmitter within the autonomic ganglion. Nicotinic receptors on the postganglionic neuron are responsible for the initial fast depolarization (Fast EPSP) of that neuron. As a consequence of this, nicotinic receptors are often cited as the receptor on the postganglionic neurons at the ganglion. However, the subsequent hyperpolarization (IPSP) and slow depolarization (Slow EPSP) that represent the recovery of the postganglionic neuron from stimulation are actually mediated by muscarinic receptors, types M2 and M1 respectively (discussed below).[citation needed]. Peripheral autonomic fibers (sympathetic and parasympathetic fibers) are categorized anatomically as either preganglionic or postganglionic fibers, then further generalized as either adrenergic fibers, releasing noradrenaline, or cholinergic fibers, both releasing acetylcholine and expressing acetylcholine receptors. Both preganglionic sympathetic fibers and preganglionic parasympathetic fibers are cholinergic. ...
TY - JOUR. T1 - Vasopressor response to angiotensin II infusion in patients with chronic heart failure receiving β-blockers. AU - Vittorio, Timothy J.. AU - Lang, Chim C.. AU - Katz, Stuart D.. AU - Packer, Milton. AU - Mancini, Donna M.. AU - Jorde, Ulrich P.. PY - 2003/1/21. Y1 - 2003/1/21. N2 - Background - A synergistic interaction between the angiotensin II (Ang II) type 1 receptor and α1-adrenergic receptors has been described. We hypothesized that the nonselective β-antagonist carvedilol, through its α1-adrenergic blocking properties, may modulate vascular reactivity to Ang II in patients with chronic heart failure (CHF). Accordingly, we compared the vasopressor response to infused Ang II in patients treated with carvedilol and metoprolol, a selective β-antagonist. Methods and Results - All subjects were treated with carvedilol or metoprolol for at least 3 months. ACE inhibitor therapy was standardized to enalapril 40 mg/d or the maximally tolerated dose. Exogenous Ang II was ...
Pain associated with prostate biopsy arises from either the prostatic capsule or stroma, where there is a rich innervation of autonomic fibers. These autonomic nerves convey visceral sensation to the spinal cord. As based on neuroanatomy studies of the prostate, the peri-prostatic approach appeared to be the best way to anesthetize the prostate. Experience with anatomical radical prostatectomy has well elucidated the nerve supply of the prostate 19, 20. Recently Hollabaugh et al also studied the neuroanatomy of the prostate using fresh cadavers 21, 22 The preganglionic fibers from the sacral roots form the pelvic nerves (pelvic splanchnic nerves or nervi erigentes) and are joined by fibers from the inferior hypogastric nerves (sympathetic) to form the pelvic plexus (a.k.a.: inferior hypogastric plexus) in the pelvic fascia on the lateral side of the rectum, seminal vesicles, prostate and posterior bladder. These nerves also receive additional sympathetic fibers from the sacral sympathetic chain ...
Rationale: Autonomic nerves from sinoatrial node (SAN) ganglia are known to regulate SAN function. However, it is unclear whether remote pulmonary vein ganglia (PVG) also modulate SAN pacemaker rhythm. Objective: To investigate whether in the mouse heart PVG modulate SAN function. Methods and Results: In hearts from 45 C57BL and 7 Connexin40+/GFP mice, we used tyrosine-hydroxylase (TH) and choline-acetyltransferase (ChAT) immunofluorescence labeling to characterize adrenergic and cholinergic elements, repectively, within the PVG and SAN. PVG project postganglionic nerves to the SAN. TH and ChAT stained nerves, enter the SAN as an extensive, dense mesh-like neural network. Neurons in PVG are biphenotypic, containing ChAT and TH positive neurons. In Langendorff-perfused hearts, we compared effects of electrical stimulation of PVG, posterior (PRCVG) and anterior right vena cava ganglia (ARCVG) using 200-2000 ms trains of pulses (300μs, 0.2-0.6mA, 200Hz). Sympathetic and/or parasympathetic ...
A sympatholytic (or sympathoplegic) drug is a medication that opposes the downstream effects of postganglionic nerve firing in effector organs innervated by the sympathetic nervous system (SNS). They are indicated for various functions; for example, they may be used as antihypertensives. They are also used to treat anxiety, such as Generalized Anxiety Disorder, Panic Disorder and PTSD. Antiadrenergic agents inhibit the signals of epinephrine and norepinephrine. They are primarily postsynaptic adrenergic receptor antagonists (alpha and beta adrenergic receptor antagonists, or blockers), inhibiting the downstream cellular signaling pathways of adrenergic receptors. However, there are exceptions: clonidine is an adrenergic agonist at the α2 receptor; since this receptor is located presynaptically, agonism at this receptor inhibits the presynaptic release of adrenaline and noradrenaline, preventing postsynaptic adrenergic receptor activation and downstream signaling. Another way to inhibit ...
The sensory & postganglionic sympathetic nerves that innervate the dental pulp originate in the trigeminal & superior cervical ganglion & enter the teeth through the apical foramen. From the neural receptor in the pulp, the central process of a trigeminal sensory neuron traverses the trigeminal ganglion located in the floor of the middle cranial fossa. The central process then synapses on a second-order neuron located in the subnucleus caudalis of the brainstem trigeminal complex. ...
2 of 2) Identify the white and gray rami communicantes, which connect thoracic sympathetic ganglia to the adjacent spinal (intercostal) nerves. White rami communicantes carry preganglionic sympathetic fibers from the spinal nerves to the sympathetic ganglia. Gray rami communicantes carry postganglionic sympathetic fibers from the sympathetic ganglia to the spinal nerves. Although white and gray rami cannot be differentiated at the gross level, verify that there are two rami communicantes associated with a spinal nerve and its corresponding ganglion. Links and References: ...
Looking for online definition of Preganglionic cell in the Medical Dictionary? Preganglionic cell explanation free. What is Preganglionic cell? Meaning of Preganglionic cell medical term. What does Preganglionic cell mean?
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Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers and of the diffuse projection system in the brain arising from the locus ceruleus. It is also found in plants and is used pharmacologically as a sympathomimetic ...
Our nervous system can seem complex to understand let alone understand how to live a balanced life. Because of all the traumas in my life … from adolescence to adulthood, I have lived in my sympathetic nervous system. That fight or flight mode. Living in the sympathetic system is great when you need it. But […]
Aging. As we age, changes in the structure of the kidneys can cause them to lose some ability to remove wastes from the blood, and the muscles in the ureters, bladder, and urethra tend to lose some of their strength. Urinary infections may occur because the bladder muscles do not tighten enough to empty the bladder completely. A decrease in strength of the muscles of the sphincters and pelvis, that may be associated with age, can also cause incontinence.. ...

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What was being tested was my autonomic, specifically sympathetic, nerve function. The QSART can identify small fiber neuropathy ... If my thermoregulatory sweat test showed lesions, it would let us know if they are pre or postganglionic. Used alone, it will ... autonomic disorders, CFS, chronic disease, disease in nervous system, Dysautonomia, Exercise test, Mayo Clinic, Postural ... Autonomic Nervous System Test. This testing was pretty much was awful. First, they put electrodes type things all over my body ...
The submandibular ganglion abuts the lingual nerve, where the postganglionic fibers originate and directly pierce the capsule ... Nerves: With the exception of the autonomic plexus to the submandibular gland, all the nerves were found external to the ... where the parasympathetic preganglionic fibers transverse through the chorda tympani of the seventh cranial nerve to join the ...
... being mainly detected in autonomic fibers of PD, DLB, and PAF, but detected in somatic fibers of the upper dermis in MSA, ... 4 reflecting the early damage of postganglionic sympathetic branches, peripheral tissues with extensive autonomic innervation, ... Skin sympathetic fiber α-synuclein deposits: a potential biomarker for pure autonomic failure. Neurology 2013;80:725-732. ... pure autonomic failure; PD=. Parkinson disease; PSP=. progressive supranuclear palsy; RBD=. REM sleep behavior disorder; RT- ...

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