exam 3 autonomic nervous system Flashcards
function of somatic nervous system
innervates skeletal muscles and receives sensory info from senses
-CNS and PNS
function of autonomic nervous system
innervates visceral (organs)
- the things body does without thinking about it
- CNS and PNS
what is the hierarchy of the ANS
- hypothalamus: oversees all ANS activity
- “middle management”: ANS centers in brainstem
- “ordinary workers”: pre/postganglionic neurons
describe process of somatic neuron signaling
motor neuron sends signals to muscle fiber, to be activated
- located in CNS and then goes to PNS
(2 total location)
describe the process of autonomic neuron signaling
sends impulse from neuron in CNS to another neuron (ganglion) in PNS, which sends axon to organ to perform function
(3 total locations)
why does ANS use 2 neuron chain?
- limited resources
- more energy effective
what is the sympathetic division
thoracolumbar
- originates in lateral horns of T1-L2 region of spinal cord
- “emergency” situations
- “flight or fight” response
- “mass action” effect
what is the parasympathetic division
cranialsacral
- some cranial/sacral nerves
- maintains homeostasis environment
- “rest and digest”
- usually discrete and localized
what are the cranial components of parasympathetic system
CN III (oculomotor) CN VII (facial) CN IX (glossopharyngeal) CN X (vagus)
what are the sacral components of the parasympathetic system
S2-S4 of spinal cord
-pelvic splanchnic nerves
parasympathetic pathway for axons
1) cell bodies of preganglionic motor neurons
2) synapse in terminal ganglia which are located close to or on the organ being innervated
3) postganglionic axons travel from the terminal ganglia to the target organ
how does the parotid gland know when to secrete saliva?
cranial nerve IX carries parasynthetic info to parotid gland, to secrete saliva
which cranial nerves innervate other salivary glands (not parotid)
cranial nerve VII (facial)
where does CN X (vagus) take parasympathetic info to
neck, thorax, abdomen
order of sympathetic division pathway
anterior roots
spinal nerve
white rami
sympathetic trunk
function of sympathetic postganglionic axons
travel directly to target organ
function of prevertebral (collateral) ganglia
- splanchnic nerves synapse here
- located in front of of vertebral column
function of splanchnic nerves
preganglionic axons that do synapse in the sympathetic trunk ganglion
function of grey rami
- runs from the sympathetic trunk to a spinal cord
- sympathetic postganglionic axons
function of sympathetic trunks
- long chain of axons on either side of vertebral column
- sympathetic trunk ganglia
function of white rami
runs from spinal nerve to sympathetic trunk
function of cell bodies of preganglionic motor neurons in lateral horns of T1-L2 segments of spinal cord
preganglionic axons exit the spinal nerve and then go to the white rami
what is the 1st option of sympathetic synapsing
some synapse in the sympathetic trunk and leave through the grey ramus, to the spinal nerves out to the skin and blood vessels
what is the 2nd option of sympathetic synapsing
synapse in the sympathetic trunk and leave anteriorly to go to the thoracic organs
what is the 3rd option of sympathetic synapsing
some preganglionic axons leave the sympathetic trunk as splanchnic nerves, to prevertebral ganglia to synapse before heading to abdominal organs
describe the parasympathetic and sympathetic functions of the iris
p: constricts pupil
s: dilates pupil
describe the parasympathetic and sympathetic functions of the salivary gland
p: stimulates secretion
s: inhibits secretion
describe the parasympathetic and sympathetic functions of the heart rate
p: decreases
s: increases
describe the parasympathetic and sympathetic functions of the lungs
p: bronchoconstrictor
s: bronchodilator
describe the parasympathetic and sympathetic functions of the digestive system
p: stimulates activity
s: inhibits activity
