ANS Flashcards
2 systems of the ANS
sympathetic and parasympathetic
basic anatomical organization of ANS
2 neurons and a ganglion
origin of preganglionic sympathetic nerves
T1-L2
origin of preganglionic parasympathetic nerves
S2-S4 and CN III, VII, IX, X nuclei in brain
length of preganglionic sympathetic nerves
short
length of preganglionic parasympathetic nerves
long
length of postganglionic sympathetic nerves
long
length of postganglionic parasympathetic nerves
short
location of sympathetic ganglion
usually in the sympathetic trunk
location of parasympathetic ganglion
in the wall of or near target organ
preganglionic sympathetic neurotransmitter
acetylcholine
postganglionic sympathetic neurotransmitter
norepinephrine
preganglionic parasympathetic neurotransmitter
acetylcholine
postganglionic parasympathetic neurotransmitter
acetylcholine
sympathetic effects on liver
stimulates glucose production and release and glycogen breakdown
parasympathetic effects on liver
stimulates glycogen synthesis and storage, stimulates bile release from gallbladder
location of preganglionic sympathetic cell bodies
IML of grey matter
path of preganglionic sympathetic neuron to synapse in standard pathway
exits grey matter via ventral root with spinal nerve and travels to paravertebral chain where it enters the ganglion via the white ramus communicans
path of postganglionic sympathetic neuron to target organ in standard pathway
exits the paravertebral chain via the gray ramus communicans and rejoins the spinal nerve to travel to the target organ
path of sympathetics to skin of extremities and body wall
pathway 1
origin of sympathetics to head
upper thoracic
path of preganglionic sympathetics to head
Pathway 2: leave the IML and spinal nerve via white ramus communicans and travel up the sympathetic chain to the top (superior cervical ganglion) where it synapses with the postganglionic neuron
path of postganglionic sympathetics to head
exits sympathetic chain and follows branches of the carotid artery to structures in the head
path of preganglionic sympathetics to thorax
Exit spinal cord at T1-T5 and enter sympathetic chain to synapse with postganglionic neurons at same level or higher
path of postganglionic sympathetics to thorax
Exit the sympathetic chain and form cardiopulmonary plexus of nerves to innervate target organs in the thorax
sympathetics to abdominal and pelvic organs origin
T5-L1
path of preganglionic sympathetics to abdomen and pelvis
exit spinal cord at T5-L1 and enter sympathetic chain and pass through it without synapsing, becoming thoracic and lumbar splanchnic nerves. They enter prevertebral ganglia in the abdominal aorta and pelvis to synapse with postganglionic neurons
path of postganglionic sympathetics to abdomen and pelvis
follow abdominal aorta and branches to get to target organs
course of parasympathetics in head
cell bodies are located in brainstem nuclei of cranial nerves III, VII, and IX and the neurons synapse with specific ganglia in the head and then travel to target organs
course of parasympathetic with CN X
originates in brainstem nuclei of CN X and synapse in ganglia in the wall of thoracic and abdominal organs and then travel to target organs
location of cell bodies for sacral outlow
IML of S2-S4
path of preganglionic sacral parasympathetics
exit the spinal cord with spinal nerves and travel to their target organs via pelvic splanchnic nerves and synapse with postganglionic nerves in wall of lower abdominal and pelvic organs
path of postganglionic sacral parasympathetics
travel via short fibers to cells within the target organ
