Jmp Anatomy Visceral Nervous System

Front 1

functional division of the visceral NS?

Back 1

Front 2

Clinical Correlate: Vagotomy
-what?
-why?
-results?

Back 2

severing vagus nerve CN X for untreatable ulcers and maybe obesity. It slows digestion and reduces hunger. Causes B12 deficiency down the line because CN X also stimulates GI tract to absorb B12

Front 3

where do GVEs come from?

Back 3

spinal nerves

Front 4

how many cells are involved in sympa effs (GVEs)?

Back 4

2 cells:
presynaptics in lateral horn of spinal cord (T1-L2)

Front 5

what are the targets of the sympa effs (GVEs) and where are they

Back 5

cardiac m, smooth m, glands within body wall (skin) and viscera

Front 6

where do ascending symp. chain signals originate?
where do descending....

Back 6

*for a signal to ascend the sympathetic chain, it must originate in T1-T5

*for a signal to descend the sympathetic chain, it must originate in T5-L2

Front 7

imagine the pathway for visceral efferents

Back 7

Front 8

how do the thorco-abdominal-pelvic splanchnics differ from the cardiopulmonary splanchnics?

Back 8

-the thoracic splanchnic nerves (greater, lesser, least) are all abdominopelvic splanchnic nerves. they travel through thorax, but innervate abd. and pelvis. They are pre-synaptic

-the cardiopulmonary splanchnic nerves are post-synaptic (not presynaptic!) They innervate thoracic viscera

Front 9

sympathetic efferents:
-come from?
-target?
-how many cells?

Back 9

-come from cranial(CN X) and sacral nerves/pelvic splanchnic nerves (S2-S4)
-targets are viscera (no skin!): cardiac m, smooth m, glands
-all two cell systems

Front 10

Vagus nerve anatomy

Back 10

the L and R vagus nerves enter the esophageal plexus and reform into A and P vagal trunks
-Remember the recurrent laryneal (R, L) nerves branching off the vagus!
*left recurrent loops around aorta
*right loops around r. subclavian
*right recurrent loops around e

Front 11

Visceral Afferents (sensory)

Back 11

-originate in viscera
-pain is diffuse, can be referred
-cell bodies are in dorsal root ganglion (like somatic sensory neurons)
-pathways tend to travel alongside sympathetic pathways, but in the opposite direction (afferent, not efferents) superior of the pelvic line
-pathways travel alongside (but opp) parasympathetic pathways below the pelvic line

Front 12

Which category does not innervate the body wall?

Back 12

Parasymathetic visceral efferents

Front 13

are parasympathetic nerves presynaptic or postsynaptic?

Back 13

presynaptic : they synapse in/on the target organ

Front 14

sympathetic pathways have __________ outflow

Back 14

thoracolumbar

Front 15

sympathetic presynaptic neurons are where?

Back 15

T1-L2 lateral horns. they travel through ventral root, spinal nerve, ventral ramus, white ramus communicans to the paravertebral ganglion T1-L2 and may ascend or descend before synapsing, OR if they are going to pelvic or abdomnal viscera they will not synapse until after the abdominopelvic splanchnic nerve synapses at the abdominal prevertebral ganglia

Front 16

where will GVEs pathways targeting the body wall leave the chain?

Back 16

at the vertebral level corresponding to the target dermatome

Front 17

How are the visceral (GVEs) nerves named when they target the body cavity?

Back 17

splanchnic (visceral) nerves that innervate the body cavity are named according to the paravertebral ganglia from which they leave the sympathetic chain ( cardiopulmonary or abdominopelvic)

Front 18

Sympathetic nerves to know: (7)
presyn or postsyn?

Back 18

1) C1-T5: Cardiopulmonary splanchnic nn, postsynaptic
2) T5-Co1: Adbominopelvic splanchnic nn, presynaptic, originating in lateral horn!
a. T5-T9: Greater thoracic splanchnic n.
b. T10-T11: Lesser thoracic splanchnic n.
c. T12: least thoracic splanchnic n.
d. lumbar splanchnic nn.
e. sacral splanchnic nn.

Front 19

What do T1-T5 presynaptic GVEs do?

Back 19

1) synapse on the paravertebral ganglion in C1-T5
2) a postsynaptic neuron travels in the cardiopulmonary splanchnic nerve to the target

Front 20

What do T5-L2 presynaptic GVEs do?

Back 20

pass through the paravertebral ganglion, becoming the abdominopelvic splanchnic nerves to T5-Co1 and terminate in the abdominal prevertebral ganglion

Front 21

How does the foregut and spleen get sympathetic innervation?

Back 21

Lateral horn T5-T9-->through paravertebral ganglion T5-T9 without synapsing -->greater thoracic splenchnic n--> celiac (prevertebral) ganglion+plexus--> postsynaptic neuron to foregut and spleen

Front 22

How does the midgut get sympathetic innervation?

Back 22

Lateral horn T10-11-->through paravertebral ganglion T10-11 without synapsing --> lesser thoracic splenchnic n--> superior mesenteric (prevertebral) ganglion+plexus--> postsynaptic neuron to the midgut

Front 23

How do the kidneys and gonads get sympathetic innervation?

Back 23

Lateral horn T12-->through paravertebral ganglion T12 without synapsing -->least thoracic splenchnic n--> aorticorenal (prevertebral) ganglion+plexus--> postsynaptic neuron to kidneys and gonads

Front 24

how does the hindgut get sympathetic innervation?

Back 24

Lateral horn T1-L2-->through paravertebral ganglion L1-L2 without synapsing -->lumbar splenchnic n--> inferior mesenteric (prevertebral) ganglion+plexus--> postsynaptic neuron hindgut

Front 25

summary of the splenchnics?

Back 25

Front 26

how does the heart get sympathetic innervation?

Back 26

Lateral horn T1-T5-->SYNAPSES at paravertebral ganglion T1-T5 or above -->sympathetic cardiac nerve, a type of cardiopulmonary splenchnic n--> Cardiac plexus on aortic arch--> postsynaptic neuron to heart

3 neurons!

Front 27

clinical correlate: vasovagal syncope

Back 27

-most common type of fainting
-caused by excessive vagal activity
-sudden rest and digest (vasovagal) attack, heart rate slows and blood pressure drops rapidly, causing pooled blood in legs and less blood to brain--> fainting

triggers include:
seeing blood, heat, stress, standing in place, extreme straining

treatment:
usually uneeded. extreme cases get low bp drugs and and possibly pacemakers

Front 28

how does the heart get parasymapthetic innervation?

Back 28

vagus--> vagal cardiac nerve, a cardiopulmonary splenchnic n-->SYNAPSE on cardiac plexus on aortic arch--> postsynaptic neuron from cardiac plexus to heart

Front 29

how does the foregut and spleen get parasymapthetic innervation?

Back 29

vagus nerve--> celiac prevertebral ganglion and plexus without synapsing--> synapse at foregut and spleen

Front 30

how does the midgut get parasymapathetic innervation?

Back 30

vagus nerve--> superior mesenteric prevertebral ganglion and plexus without synapsing--> synapse at midgut

Front 31

how do the kidneys and gonads get parasympathetic innervation?

Back 31

vagus--> aorticorenal prevertebral ganglion and plexus without synapsing-->synapse at kidneys and gonads

Front 32

how does the hindgut get parasymathetic innervation?

Back 32

cell body in sacral spinal nerves S2-S4 (via cauda equina)--> presynaptic cell travels along the pelvic splanchnic nerve to synapse on the target in the hindgut

*this is unlike the symapthetic innervation in this one case(do not go through a ganglion+plexus), just straight to the target

Front 33

where is the pelvic pain line?

Back 33

half way through the sigmoid colon
above it, pain (GVA) follows the IMG and lumbar splenchnic to the CNS
below it, pain (GVA) follows pelvic splenchnic to the CNS