PHYS20008 Lecture Notes - Lecture 12: Postganglionic Nerve Fibers, Vagus Nerve, Sympathetic Nervous System
8 May 2019
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Document Summary
The vagus nerve is a cranial nerve is our major parasympathetic output (branches out across most of the body) In the periphery, each type of ans have 2 stages of neurons: Sympathetic lie in the spinal cord. Sympathetic lie closer to the spine. Parasympathetic right next to the target tissue. Hormone released into circulation by adrenal glands. Parasympathetic muscarinic target tissue receptor (it"s a type of cholinergic receptor which means it receives acetylcholine) Nicotinic receptors are on the post-ganglionic cell, receiving from pre-ganglionic, for both sympathetic and parasympathetic. Adrenal glands sit on top of the kidneys. Preganglionic sympathetic neuron comes from the spinal cord and meets the chromaffin cells (modified postganglionic neuron) in the adrenal medulla. It has nicotinic receptors attached to it, and when activated releases adrenaline (epinephrine) into the bloodstream to reach target tissues. They can be excitatory (eg increasing heart rate) or inhibitory (eg slowing gut movements during fight of flight)
