L11 ANS Flashcards
What has both sensory and motor divisions?
PNS
what is the enteric NS?
self-contained collection of nerve plexuses that surround the GI tract and receive inputs from both SNS and PNS nerves
aka “little brain”
what makes up the central autonomic network?
some cerebral cortex - limbic cortex
hypothalamus
brainstem
spinal cord
what is the ANS function of the hypothalamus?
temperature
osmolarity
what is the ANS function of the midbrain?
visual
what is the ANS function of the medulla oblongata?
respiration
heart rate
blood pressure
what are characteristics of the ANS?
visceral functions
involuntary
what are characteristics of somatic nervous system?
conscious control - muscles
voluntary
what are characteristics of somatic motor neurons?
1 long, heavily myelinated axon from CNS to effector - no ganglia
releases ACh
cell body in CNS
what are characteristics of ANS neurons?
preganglionic neuron has lightly myelinated axon = always release ACh
postganglionic neuron is unmyelinated and goes to effector = may release NE, ACh, neuropeptides
most visceral organs are innervated by SNS and PNS which causes?
dual innervations = dual antagoisms - both divisions counterbalance each other!
what division of the ANS can override?
SNS can override PNS during times of stress
what are only innervated by SNS?
vascular smooth muscle sweat glands piloerector muscles liver adipose tissue kidney
what are only innervated by PNS?
gastric/pancreatic secretions
lacrimal glands
where are the cell bodies of SNS?
thoracolumbar region
where are the cell bodies of PNS?
craniosacral region
why is the adrenal medulla considered a modified or specialized ganglion?
T8-12 synapse DIRECTLY on adrenal medulla - it has receptors etc.
what is the NT linking all preganglionic neurons rto postganglionic neurons?
ACh
what NT links postganglionic neurons to effector organs in PNS?
ACh
what NT links postganglionic neurons to effector organs in SNS?
NE
what are the receptors on effector muscles?
alpha and beta - NE
muscarinic - ACh
when is NE NOT the NT of the SNS?
- skeletal muscles - ACh
- sweat glands - ACh
- vascular smooth muscle - ACh
- adrenal medulla - epi (80%) and NE (20%)
what are chromaffin cells?
in the middle portion of the adrenal medulla
neuroendocrine cells
the adrenal medulla acts as a combo of what?
symp ganglion and gland
