Week 2 Autonomic NS- Severson Flashcards
Where are the cell bodies of the autonomic sensory neurons located? What is their morphological structure?
dorsal root ganglia
pseudounipolar
Where are the cell bodies of the sympathetic motor neurons?
Preganglionic cell bodies are located in T1-L2 lateral horn and into the paravertebral (prevertebral) ganglia = multipolar, myleinated
Postganglionic cell bodies are located in the paravertebral ganglia or the prevertebral ganglia = multipolar, NOT myleinated
Where are the cell bodies of the parasympathetic motor neurons located?
Preganglionic cell bodies are located in the brain stem (CN 3,7,9, 10) and the sacral spinal cord segments (S 2,3,4)
Postganglionic cell bodies are located in the parasympathetic “ganglia” that are located in or on their target organ
Trace the sympathetic preganglionic neuron from its cell body to the sympathetic chain
a. CNS lateral horn cell bodies
b. Exit through ventral ROOTS
c.Become part of the MIXED
SPINAL NERVE
d. Go into the VENTRAL RAMUS of the spinal nerve
e. Exit the ventral ramus through the WHITE RAMUS COMMUNICANS
f. Enter the PARAVERTEBRAL CHAIN GANGLIA
- What course may the sympathetic preganglionic neuron take once it has entered the sympathetic chain?
a. Ascend to terminate in a higher vertebral ganglion
b. Descend to terminate in a lower vertebral ganglion
c. Leave the paravertebral ganglion WITH OUT terminating to become a splanchnic nerve (preganglionic and myelinated) → splanchnic nerves synapse on prevertebral ganglia
d. Terminated with a postsynaptic neuron of the paravertebral ganglion at the level they enter the chain at
- What spinal cord segments give rise to sympathetic preganglionic neurons and where are the cell bodies of these neurons located? Where will the preganglionic neurons terminate?
a. T1-L2 spinal cord segments give rise to the sympathetic preganglionic neurons
b. The cell bodies of the sympathetic preganglionic neuron are located in the lateral horn (T1-L2)
c. The sympathetic preganglionic neurons terminate in the paravertebral ganglia or the prevertebral ganglia
Contrast the location of the sympathetic paravertebral and prevertebral ganglia and how each of these ganglia are innervated.
a. Paravertebral ganglia form a “chain” that run on either side of the spinal cord and are innervated my myleinated white matter
b. Prevertebral ganglia are located in a midline adjacent to the abdominal aorta and are innervated by splanchnic nerves
- Compare the innervation of the adrenal (suprarenal gland) medulla with innervation of other abdominal organs.
a. Adrenal medullary cells receive DIRECT input from PREganglionic neurons originating in spinal cord segments T10-L2
b. Adrenal medualla cells contain and release epinephrine and some norepinephrine
c. Other abdominal organs are innervated by postganglionic neurons
- What cranial nerves give rise to the parasympathetic nervous system? Differentiate between the origin (preganglionic or presynaptic neurons) of the cranial and sacral components of the parasympathetic nervous (craniosacral) system.
a. Cranial nerves 3,7,9 and 10 and sacral nerves 2,3,4 give rise to the parasympathetic nervous system
b. Parasympathetic neurons from the cranial nerves have their cell bodies in the brain stem
c. Parasympatheric neurons from the sacral nerves have their cells bodies in the lateral portion of the gray matter of spinal cord segments S2-S4 (travel with the ventral rami but then separate into a separate pelvic plexus
What neurotransmitters do the pre and post ganglionic cells of the sympathetic nervous system release?
Pre-ganglionic = release ACh that binds to nicotinic receptors on post-ganglionic nerve
Post-ganglionic= release norepinephrine
What neurotransmitters do the pre and post ganglionic cells of the parasympathetic nervous system release?
Pre-ganglionic= release ACh that binds to nicotinic receptors on postganglionic nerves
Post-ganglionic= release ACH that binds to muscarinic receptors
What does parasympathtic stimulation do?
vasodilation
increased peristalsis
increased secretion of the gastrointestinal glands
What does sympathetic stimulation do?
vasoconstriction
inhibition of peristalsis
contraction of the involuntary gastointestinal sphincters
