BIOL 240 Lecture Notes - Lecture 25: Negative Feedback, Sympathetic Trunk, Splanchnic Nerves
Document Summary
Low blood calcium levels detected by parathyroid gland. Rising calcium levels in blood inhibits pth release. Functions: bone formation, muscle contraction, neurotransmitter release. Neural stimulus sympathetic division of ans. Located just above the kidney: more 30 in total. Many steroid hormones, including estrogen and androgens. Adrenal cortex: outer layer, secretes lipid based steroid hormones, called corticosteroids, mineralocorticoids, aldosterone is main one, regulated na and k, glucocorticoids. Cortisol is main one: regulates salt, sugar, sex. Inner central core: secretes epinephrine and norepinephrine. Postganglionic sympathetic nerve pathway: synapsis occurs in sympathetic trunk, postganglionic axon leaves sympathetic trunk and reaches organs; forms plexus. Adrenal medulla pathway: preganglionic axon synapse in secretory cells of adrenal medulla (major organ of sympathetic nervous system) Splanchnic nerve pathway: synapsis in prevertebral ganglion, uses splanchnic nerves, abdominal and pelvic organs. Can cause body wide release of epinephrine or norepinephrine in an extreme emergency.
