Flashcards in Ach: Nerves of the Abdomen Deck (34):
What are the two types of nerves found in the abdomen and pelvis?
Autonomic (motor and sensory)
What are the two anatomical divisions of the nerves that supply the abdomen and pelvis?
Parasympathetic (brain stem and spinal cord segments S2-S4)
INHIBIT peristalsis and vasoconstrict
STIMULATE peristalsis, relax sphincters, stimulate glandular secretion
What makes up the visceral efferent nerves?
1. sympathetic nerves (T1-L2)
2. parasympathetic nerves (CN X, S2, S3, S4)
What are the two types of visceral efferent sympathetic nerves that serve the abdomen and pelvis?
1. thoracic splanchnics
2. lumbar splanchnics
PREganglionic sympathetic fibers from T5-T12 of the spinal cord that pass through the sympathetic trunk w/out synapsing and travel to prevertebral ganglia/plexuses
greater splanchnic (T5-T9)
lesser splanchnic (T10-11)
Least splanchnic (T12)
PREganglionic sympathetic branches
exit from lumbar sympathetic trunk at L1-L4
Where does the sympathetic outflow end?
L2 spinal cord level
Where do the lumbar splanchnic nerves from L1-L2 spinal cord exit?
travel down the sympathetic trunk and exit at L3 and L4 and synapse in prevertebral ganglia and plexuses.
What are the two types of visceral efferent parasympathetic nerves?
1. Vagus nerves
2. Pelfvic splanchnic nerves (S2-4)
Vagus nerve (parasympathetic visceral efferent)
Supply organs PROXIMAL to left colic flexure (foregut and midgut)
PREganglionic parasympathetic that DO NOT SYNAPSE in prevertebral ganglia, pass through plexuses and follow arteries to the wall
Pelvic splanchnics (parasympathetic visceral efferent)
Organs DISTAL to left colic flexure (hindgut)
PREgang exit from S2-4 spinal cord levels>
ascend to abdomen via hypogastric plexuses>
synapse on POSTgang fibers in organs distal to left colic flexure
What are the two types of visceral afferent fibers?
Sympathetic and parasympathetic
Sympathetic visceral afferent fibers: path
Viscera> splanchnic nerves> dorsal root ganglia at T1-L2 of the spinal cord
Sympathetic visceral afferent fibers: carry?
visceral pain from organs to CNS (dull and vague)
What is referred pain?
spinal cord segments receive both somatic and visceral sensory input that converges on second order neurons.
visceral pain is experienced in somatic tissues supplied by the same cord segment
Parasympathetic visceral afferent nerves: proximal vs distal to L colic flexure
Proximal: Fibers> sensory ganglion of the VAGUS
Distal: fibers: dorsal root ganglia S2-S4 in the PELVIC SPLANCHNIC NERVES
Parasympathetic visceral afferent nerves: function?
provide sensory limb for homeostatic reflexes and pain sensation from some pelvic organs
Where do preganglionic sympathetic fibers of thoracic and lumbar splanchnic nerves synapse?
Where are postganglionic sympathetic fibers located?
fibers follow blood vessels to the organ they supply
Where are preganglionic parasympathetic fibers located?
pass THROUGH plexuses and DO NOT SYNAPSE.
follow arteries to a specific portion of the gut>
snapse on postganglionic parasympathetic neurons in the muscular wall
Celiac ganglion/plexus: location?
encircles the celiac trunk
Celiac ganglion/plexus: receive?
greater and lesser splanchnic nerves (sympathetic) that synapse there
Celiac ganglion/plexus: offshoots?
aorticorenal plexus (receives the lesser splanchnic)
Celiac ganglion/plexus: what passes through w/out synapsing?
vagal preganglionic parasympathetis
superior and inferior mesenteric ganglia/plexus and intermesenteric plexus: location?
On the AORTA surrounding the SMA and IMA
(plexus extends btwn the SMA and IMA)
superior and inferior mesenteric ganglia/plexus and intermesenteric plexus: synapses here?
upper two lumbar splanchnics (L1,2)
superior mesenteric plexus: passes through?
Is there vagal input to the intermesenteric or inferior mesenteric plexuses?
NO --vagus supplies parasympathetics to the foregut and midgut ONLY
superior hypogastric plexus: locate?
level of bifurcation of hte aorta L5
superior hypogastric plexus: receives?
PREgang sympathetic fibers from L3/4 splanchnic nerves
superior hypogastric plexus: divides into?
R and L hypogastric nerves that descend into the pelvis and contribute to the IHP