PHSI 208 Lecture Notes - Lecture 15: Adrenal Medulla, Acetyl-Coa, Sympathetic Ganglion
Document Summary
The adrenal medulla secretes catecholamines (epinephrine and norepinephrine) Adrenal medulla = a specialized neuroendocrine structure associated w/ the sympathetic ns: acts as a second pathway in the sympathetic ns, adrenal medulla = a modified sympathetic ganglion, adrenal cortex = a true endocrine gland. Often described as a modified sympathetic ganglion, contain chromaffin cells which are modified postganglionic neurons. Preganglionic sympathetic neuron adrenal medulla (contains chromaffin cells that release epinephrine) epinephrine is released in the blood and binds to adrenergic receptors. These two pathways are activated when the sympathetic division is activated. Target smooth and cardiac muscle, many exocrine glands, a few endocrine glands, lymphoid tissue and some adipose tissue: the main job of the autonomic ns is to maintain homeostasis. Axons of the autonomic neurons have varicosities in their distal portions: varicosities contain that neurotransmitter to be released (ach from parasympathetic neurons, ne from sympathetic neurons, the synapse is called the neuroeffector junction.
