PHGY 209 Lecture Notes - Lecture 20: Enteric Nervous System, Solitary Tract, Vagus Nerve
Document Summary
When norepinephrine is released, e. g. onto heart, changes the physiology of the heart. In sympathetic, preganglion neuron in sympathetic system is located in the thoracic region of the spinal cord. In parasympathetic, preganglion neuron is in the brain stem. There"re neurons that go to eyes ears etc, but the major output of the ans is to the. Sympathetic & parasympathetic have opposing effects on target tissues. Note: this doesn"t mean that norepinephrine is a stimulator and acetylcholine is a depressor. It"s just that the two work opposed to each other. Vagus nerve (x): an output nerve. (a nerve is a bundle of axons) Brainstem: integrates visceral sensory inputs & autonomic outputs and project to higher brain centers involved in homeostasis. Enteric nervous system small intestine, where digestion occurs, is always contracting. This contraction is controlled by a complex group of neurons that line the digestive tract. This is also present in stomach and large intestine but mostly in small intestine.