9-Autonomic Nervous System Figs BW

Theres no synapse and theres no specialized structure

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Unformatted text preview: membrane of postsynaptic where receptors are) is very wide. there's no synapse and there's no specialized structure. the neurotransmitters have to diffuse considerable distance in order to reach target organ. all these put together (the small, unmyelinated axon, neurotransmitter have to diffuse through long distance) means this system is not a rapid, active system, rather changes caused by postsynaptic cell ANS will develop slowly but more long lasting. Postganglionic Sympathetic Synapses the neurotransmitter being release by presynap is noraepinerine. bottom is target cell. epinephrine accumulate because postgang lack enzyme to convert norepineph to epinephrine. which neurotransmitter relesase depend on enzyme. they bind to adrenergic receptor (G-Protein coupled). you have vesicles of neurotransmitter, v-gated ca cause release of vesicles. the synaptic cleft can be substantial. this is halfway synaptic and paracrine. neurotransmitter is breakdown through binding of COMT, recycle back to cleft (broke down by monoamine oxidase). MAO inhibitor prolong existence of norepinephrine in existing tissue. * *monoamine oxidase COMT* *catecholamine-Omethyltransferase tyrosine DOPA dopamine norepinephrine Catecholamines epinephrine Autonomic Pathways 1 2. prevertebral ganglia is located at the abdomen. red and blue dot=...
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