Intro to ANS Flashcards
ANS
portion of the central and peripheral NS that is responsible for unconscious control of the visceral function
Parasympathetic
CONSTANT control of visceral function
i.e. decreased heart rate, shunting of blood toward the gut away from the skeletal muscle
cranial part of the parasympathetic division
cranial nerves III VII IX X
sacral part of parasympathetic division
lateral horn (intermediolateral cell column)
S2
S3
S4
sympathetic division
responsible for control of visceral reaction response to IMMEDIATE STRESS (fight or flight)
thoracolumbar portion of sympathetic division
IMLCC lateral horn of spinal cord levels T1-L2
collection of neurons within the CNS?
nucleus
NOTE***
visceral efferent fibers of the ANS are accompanied by visceral afferent fibers
visceral afferents PARALLEL the course of the sympathetic division, generally carrying visceral pain
visceral afferents (mostly vagal) can be FOUND WITHIN branches of cranial nerves VII, IX and X . These are responsible for the modailty of distention (feeling full)
where are the presynaptic neuron cells bodies of the sympathetic nervous system found?
in the CNS–> intermediolateral cell column
the intermediolateral cell column is found from T1-L2
where do the cell bodies of postsynaptic neuron of the sympathetic NS reside?
2 types
paravertebral ganglia
AND
prevertebral ganglia
paravertebral ganglia
sympathetic trunk/chain ganliga
extend the length of the spinal column
attached to spinal nerve trunks (rami) which conduct specific nerve fibers (white and gray ramus communicans)
white ramus communicans
conduct MYELIN preganglionic sympathetic fibers from a spinal nerve to a paravertebral ganglion
Gray ramus communicans
conduct unmyelinated post-ganglionic sympathetic fibers from a paravertebral ganglion to a spinal nerve
pre-vertebral ganglia (collateral)
located ANTERIOR to the vertebral column (anterior to the aorta)
includes:
celiac
aorticorenal
superior and inferior mesenteric ganglia
preganglionic fiber of ANS
efferent fiber from the preganglionic neuron (cell bodies located within CNS)
postganglionic fiber of ANS
fiber from the second neuron (cell bodies located within peripheral ganglion)
for the parasympathetic nervous system where does the postganglionic fiber reside typically?
within the walls of organs that it innervates
EXCEPT in the head specifically where parasympathetic ganglia exist near organs (salivary glands and eyes)
what is the vagus nerve and what does it innervate
CNX
innervates thoracic and abdominal viscera (most of the GI tract)
sympathetic division of ANS innervates
all visceral organs AND visceral organs of the periphery
pass out INTO SPINAL NERVES
upper limb
T2-T7
lower limb
T10-L2/3
body wall
T7-L1
eyes
T1-T2
Head, salivary glands
T1-3,4 (head AND neck)
heart
T1-5
lungs
T2-6