01:830:331 Lecture 19: lecture 19
24 Jul 2016
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~when body is excited, sympathetic system increases blood flow to muscles, stimulates secretion of adrenaline, causes goosebumps (piloerection) ~cells bodies of sympathetic motor neurons are in gray matter of thoracic and lumbar regions. ~the axons exit the spinal cord via ventral roots. After being fused into spinal nerves, the fibers go to synapse with sympathetic ganglia. The chain ganglia are lined up vertically right next to the spinal cord. The preganglionic cells (from spinal cord gray matter) synapse at the chain ganglia, postganglionic fiber goes to target effector organ. Preganglionic axons (synapsing on chain ganglia) use acetylcholine as nt. Postganglionic axons (synapsing on organs) use norepinephrine as nt, except for the ones synapsing with sweat glands, which use ach. Some axons do not synapse at the chain ganglia, they just pass through. ~sympathetic nervous system controls adrenal medulla group of cells near adrenal gland. The adrenal medulla is like a sympathetic ganglion.
