What is the function of the Parasympathetic division of the ANS?
maintains homeostasis (a stable physiological state)
What type of situations is the Parasymphathetic division of the ANS used?
normal, non-stressful events
What is the function of the Sympathetic division of the ANS?
prepares for stressful situations
What type of situations is the Sympathetic division of the ANS used?
"fight or flight" reactions
What kind of neurons comprises the ANS?
What structures do the motor neurons of the ANS innervate?
cardiac muscle (in heart)
smooth muscle (in most hollow organs)
glands (both endocrine and exocrine)
How are the motor neurons of the ANS organized?
in a two-neuron chain between the CNS and the effector (target) organ
Where is the nerve cell body of the first motor neuron of the ANS found?
in the CNS
What is the first motor neuron of the ANS in the CNS known as?
a preganglionic neuron
Where is the nerve cell body of the second motor neuron of the ANS found?
in a ganglion in the peripheral nervous system (PNS)
What is the second motor neuron of the ANS in the PNS known as?
a postganglionic neuron
What does GVE stand for?
geneal viseral efferent
The motor neurons of the GVE go to what structures?
What is the Sympathetic Division of the ANS known as?
Where does the Sympathetic Division of the ANS orginate?
spinal cord levels T1-L2
Which horn of the spinal cord is at spinal cord levels T1-L2?
Where are prganglionic nerve cell bodies of the Sypmathetic division located?
in the intermediolateral (IML) cell column
Preganglionic nerve fibers of the Sympathetic division exit the CNS via which nerve roots and enter where?
exit via ventral spinal nerve roots
enter spinal nerves T1-L2
Which communicating rami do preganglionic nerve fibers of the sympathetic division pass through?
white communicating rami
How many pairs of white communicating rami are present in the sympathetic division?
What are the 14 pairs of white communicating rami associated with?
spinal nerves T1-L2
What are the 3 options for the preganglionic nerve fibers of the sympathetic division once they enter the sympathetic chain ganglia?
1. synapse with postganglionic neurons at the same level
2. ascend to a higher level or descend to a lower level to synapse (if needed outside of T1-L2)
3. continue on to a collateral ganglion in the abdominal or pelvic cavity before synapsing
How does a preganglionic nerve fiber of the Sympathetic division get to a collateral ganglion?
via splanchnic nn.
Reminder: what does the GSE supply?
soma; skeletal muscles
What is the sympathetic chain ganglia?
bilateral structures located adjacent to (parallel) the vertebral column
Where do the sympathetic chain ganglia extend to?
vertically from base of skull to coccyx (on both sides of vertebral column)
What connects the sympathetic chain ganglia to the spinal nerves?
white communicating rami
gray communicating rami
Do any spinal nerves go to body cavities?
Are gray communicating rami associated with prganglionic or postganglionic neurons?
Are white communicating rami associated with preganglionic or postganglionic neurons?
How many pairs of gray communicating rami are there?
What are the 31 pairs of gray communicating rami associated with?
all spinal nerves
Is the Visceal Reflex Arc part of the ANS?
What types of neurons are required for the visceral reflex arc?
sensory coming from viscera
Are there motor neurons in dorsal nerve roots?
no, only sensory
What are the components of the Visceral Reflex Arc?
Sensory neuron -General Visceral Afferent (GVA)
Connecting neuron (in spinal cord)
Two motor neurons (GVE with pre/postganglionic neurons)
What are the two portions of the Parasympathetic division of the ANS?
Where does the cranial portion of the parasympathetic division originate?
in brain stem
Where do preganglionic cranial parasympathetic neurons originate?
brain stem motor nuclei
What cranial nerves is the brain stem motor nuclei associated with?
CN III, VII, IX, and X
Where are preganglionic nerve fibers of the cranial parasympathetic division distributed to?
cranial region in conjunction with 4 parasympathetic ganglia
thoracic and abdominal viscera
The preganglionic nerve fibers of the cranial parasympathetic division are distributed to the crainal region in conjunction with four parasympathetic ganglia that are associated with which cranial nerves?
CN III, VII (two ganglia) and IX
The preganglionic nerve fibers of the cranial parasympathetic division are distributed to the thoracic and abdominal viscera via:
Where does the preganglionic nerve fiber of the cranial parasympathetic division synapse with the viscera via CN X?
walls of target organs
What is the name of CN X?
What does the name "vagus" imply about the vagus nerve?
wanders from place to place
Does the vagus nerve (CN X) supply the GI tract?
does not supply all of GI tract, just some
Which part of the GI tract does the vagus nerve (CN X) supply?
everything up to the splenic flexure
Where are the short postganglionic fibers of the cranial parasympathetic division contained?
entirely within walls of target organs
Where is the sacral portion of the parasympathetic division located?
spinal cord levels S2-4
The preganglionic nerve fibers of the sacral parasympathetic division exit the CNS via which nerve roots and neter what?
exit via ventral spinal nerve roots of S2-4
enter pelvic splanchnic nerves
What is another name for the pelvic splanchnic nerves?
Where are the pelvic splanchnic nerves distributed to?
pelvic viscera and external genitalia
Where do the preganglionic fibers of th sacral parasympathetic division symapse with short postganglionic neurons?
in the walls of target organs
The postganglionic neurons of the sacral parasympathetic division are contained entirely within:
the walls of target organs
What are neurotransmitters?
chemicals released at synapses between pre- and postganglionic neurons and between postganglioic neurons and effector organs
What hormone gives the adrenaline rush?
Epinephrine has the same physiological effect as what other hormone?
The parasympathetic preganglionic neuron releases which neurotransmitter?
The parasympathetic postganglionic neuron releases which neurotransmitter?
The sympathetic preganglionic neuron releases which neurotransmitter?
The sympathetic postganglionic neuron releases which neurotransmitter?
The sympathetic preganglionic neurons to sweat glands releases which neurotransmitter?
The sympathetic postganglionic neurons to sweat glands release which neurotransmitter?
The sympathetic preganglionic neurons to the suprarenal medulla release which neurotransmitter?
What does the suprarenal medulla secrete?
epinephrine into blood stream
What is a ganglion?
collection of nerve cell bodies in PNS
What is an autonomic ganglion?
where two neurons synapse
The splanchnic nerves connect to:
The pelvic splanchnic nerves are associated with which spinal nerves?