Ach: Nerves of the Abdomen Flashcards
What are the two types of nerves found in the abdomen and pelvis?
Somatic (phrenic)
Autonomic (motor and sensory)
What are the two anatomical divisions of the nerves that supply the abdomen and pelvis?
Sympathetic (T1-L2)
Parasympathetic (brain stem and spinal cord segments S2-S4)
sympathetics
INHIBIT peristalsis and vasoconstrict
parasympathetics
STIMULATE peristalsis, relax sphincters, stimulate glandular secretion
What makes up the visceral efferent nerves?
- 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?
- thoracic splanchnics
2. lumbar splanchnics
thoracic 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)
lumbar splanchnics
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?
- 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) exit?
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