Exam #4
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
卡片预览 (24 张)
3 types of cells the ANS controls
smooth muscle cells cardiac muscle cells gland cells
where do SNS preganglionic fibers originate
thoracolumbar region of the spinal cord (T1-L2/3)
where do SNS preganglionic cell bodies lie in the spinal cord
intermediolateral horn
where do SNS preganglionic cell fibers pass through in the spinal cord
ventral root
where do SNS preganglionic fibers travel once they leave the spinal canal
pass through white ramus, into one of the ganglia of the sympathetic chain
what can SNS preganglionic neurons do once they are inside the sympathetic chain
synapse with post ganglionic neuron in the ganglion (travel through gray rami to periphery) Go up or down the sympathetic chain to synapse at another level exit the chain to an outlying collateral ganglion where they can synapse with a peripheral synpathetic ganglion
where do post ganglionic sympathetic neurons originate
one of the sympathetic chain ganglia one of the peripheral sympathetic ganglia
5 peripheral sympathetic ganglia
celiac superior mesenteric aorticorenal inferior mesenteric hypogastric
what is released at the terminal end of the SNS preganglionic neuron
ACh
SNS preganglionic fiber length
short
SNS post ganglionic fiber length
long
what is released at the terminal end of the post ganglionic neuron at synapses with target organ
NE
chromaffin cells
ACh interacts with them to release EPI and NE in the adrenal medulla
catecholamine content released by chromaffin cells
80% EPI 20% NE
how long do hormonal EPI and NE last vs direct stimulation
10x longer
what is the result of SNS stimulation of the liver
glycogenolysis– glucose released into the blood
synthesis of NE
tyrosine+ tyrosine hydroxylase-> DOPA+ decarboxylase-> dopamine+ DBH-> transported into vesicles and converted to NE
3 mechanisms by which NE is removed after the release into the synapse
reuptake into the presynaptic terminals (active transport) diffusion away from nerve endings destruction by tissue enzymes (MAO and COMT)
What does the metabolism of NE form
VMA
what is VMA
the major metabolite (80-90%) of NE found in urine
are SNS preganglionic fibers myelinated or unmyelinated
myelinated
preganglionic fiber to postganglionic fiber ratio in SNS
1:20-30
NE negative feedback loop
NE binds in the presynaptic post ganglionic sympathetic nerve terminal to a2 receptors and NE release is decreased
where does PSNS arise from
CN3,7,9,10 sacral segments 1-4 The craniosacral outflow