Exam #5 chapter 16 part 1 Flashcards
what is one similarity between the ANS and SNS?
they are both motor divisions of the PNS controlling different effectors
where are somatic motor neuron cell bodies located?
in the anterior gray horn or a cranial nerve motor nucleus
where does a somatic motor neuron cell body’s myelinated axon extend to?
the skeletal muscle
where are autonomic motor neuron cell bodies located?
in the lateral gray horn or a cranial nerve nucleus
how many neurons reach the ANS effectors?
2
what are the 2 neurons in the ANS?
preganglionic and postganglionic
where do the 2 neurons of the ANS synapse?
in an autonomic ganglion
what is different about the pregangliotic and postgangliotic neurons?
the pregangliotic neuron axon is myelinated the postgangliotic is not
what is a difference between the ANS and SNS?
somatic motor neurons are always excitatory and autonomic motor neurons are either excitatory or inhibitory.
what are both somatic and autonomic motor neurons involved in?
reflexes
what are some ways that the sympathetic and parasympathetic divisions of the ANS are different? (2) (LL)
1) the location of the preganglionic neuron and location of their input to the CNS
2) the location of the autonomic ganglia and the relative lengths of their preganglionic and postganglionic axon (in respect to spinal cord)
where is the sympathetic ganglia located?
they are close to spinal cord making the preganglionic axon short and postganglionic axon long
where is the parasympathetic ganglia located?
far from the spinal cord making the preganglionic axon long and the postganglionic axon short
what is another name for the sympathetic division?
thoracolumbar division
where are the preganglionic motor neuron cell bodies located in the sympathetic division?
in the lateral gray horns of the T1-L2 sections of the spinal cord
where is the sympathetic output of the CNS?
in T1-L2 spinal nerves
where do the preganglionic motor neurons exit the spinal cord?
in the ventral root
what does the preganglionic motor neurons do after they exit the spinal cord via the ventral root?
enter the spinal nerve and goto the sympathetic ganglion
where are paired sympathetic chain (paravertebral) ganglia located?
near the vertebrae
where do sympathetic chain ganglia extend from?
from the cervical to sacral regions and are connected to each other
how many of each ganglia are there usually in the sympahtetic division?
3 cervical, 11 thoracic, 4 lumbar and 4 sacral ganglia
where are the 3 unpaired collateral (prevertebral) ganglia located?
on the anterior space of the abdominal aorta
where is the abdominal aorta?
just anterior to the vertebral bodies
how do all sympathetic preganglionic motor neurons enter the sympathetic chain?
by a short white ramus communicans from the spinal nerve
what does the white ramus communicans contain?
myelinated axons
what are the 4 routes taken by the sympathetic axons?
1) spinal nerve
2) sympathetic nerve
3) splanchnic nerve
4) adrenal medulla
in the spinal nerve route what do they synapse with?
post ganglionic neuron whose axon extends out the spinal nerve to the effectors in the body wall
in the spinal nerve route what does the pregangliotic neuron synapse with?
the postgangliotic neuron cell body in the sympathetic ganglion
in the spinal nerve route what does the postganglionic axon enter?
the gray ramus communicans
in the spinal route where does the postganglionic axon exit?
the ventral or dorsal rami to each effectors in the body wall
in the sympathetic nerve route where are the effectors ?
in the thoracic cavity
where does the preganglionic axon synapse with the post ganglionic axon in the sympathetic nerve route?
in the sympathetic chain ganglion
where do the sympathetic nerves leave the sympathetic chain ganglia and what effectors do they travel to?
in the thoracic region and travel to thoracic effectors
where do they exit during the splanchnic nerve?
the sympathetic ganglia
where do they enter during the splanchnic nerve route
collateral ganglia
what do they synapse with during the splanchnic nerve route?
postganglionic neurons whose axons extends to abdominal effectors
where do preganglionic axons exit during the splanchnic nerve route:?
the sympathetic chain ganglia
what happens after they exit the sympathetic chain ganglia during the splanchnic nerve route?
without synapsing in splanchnic nerves that travel to 1 of 4 collateral ganglia
which postganglionic axons do they preganglionic axons synapse with during the splanchnic nerve route?
those whose axons follows autonomic nerves to effectors in the abdominal cavity
what are the steps of the adrenal medulla route? (5) (EEEES)
1) exit the sympathetic ganglia without synapsing
2) enter splanchnic nerves
3) enter collateral ganglia without synapsing
4) enter the adrenal medulla
5) synapse with cells
what does the adrenal medulla contain?
neural cells without axons or dendrites
what does the adrenal medulla release?
epinephrine and norepinepherine which enter the bloodstream
what doe the two hormones epinepherine and norepinepherine stimulate?
most sympathetic effectors
