Abdominal Autonomic Innervation Flashcards
Foregut, midgut, and hindgut major blood supply
. Fore: celiac trunk
. Mid: sup., mesenteric a.
. Hind: inf. Mesenteric a.
Foregut organs
. Liver . Gallbladder . Cancreas ,. Spleen . Stomach . Prox. Half duodenum
Midgut organs
. Distal half duodenum through 2/3 transverse colon
Hindgut organs
. Distal 1/3 colon through rectum
Paravertebral ganglia
. Assoc. w/ structures in body wall
. Sympathetic chain
Prevertebral ganglia
. Assoc. w/ structures in body cavity
. Located ant. To vertebral bodies or abdominal aorta
General Structures w/in body wall that get sympathetic innervation
. Vessels
. Glands
. Heart and lungs (considered part of body wall)
General Structures w/in body cavity that get sympathetic innervation
. Smooth muscles in gut walls, sphincters, arteries, and glands
General location of cell bodies of preganglionic ganglia
. T1-L2/3 levels (thoracolumbar outflow)
General location of postganglionic sympathetic fibers going to tissue in body wall
. Paravertebral ganglia
General location of postganglionic sympathetic fibers going to tissues in body cavity
Prevertebral ganglia
Pathway of sympathetic neurons going to tissues in body cavity
. Preganglionic sympathetic neurons travel through white rami communicantes to sympathetic chain but don’t synapse and leave via thoracic/lumbar splanchnic nn.
. Nerves leave thorax and move into abdomen where they synapse in prevertebral ganglia
. Postganglionic sympathetic fibers course in autonomic plexuses on aa. To reach target viscera
Autonomic plexuses on aorta
. Mixed
. Contains preganglionic and postganglionic sympathetic fibers going to and from prevertebral ganglia
. Preganglionic parasympathetic fibers going to abdominal viscera
. Visceral sensory fibers coming from abdominal viscera
Sympathetic innervation of foregut
. Cell bodies of preganglionic sympathetic neurons at T5-9
. Travel through white rami to sympathetic chain but DONT synapse
. Pass through sympathetic chain and leave in greater thoracic splanchnic n.
. Descends along anterolat. Sides of thoracic/lumbar vertebral bodies
. Greater splanchnic n. Pierces diaphragm and enters abdomen and course on abdominal aorta in autonomic plexuses
. Synapse in celiac ganglion then course w/in autonomic plexuses on branches of celiac trunk to organs
General pathway of Sympathetic innervation to small and large intestine
. Cell bodies in T10-L2/3
. Go to sympathetic trunk via white rami and don’t synapse
. Conveyed in thoracic lesser and least and lumbar splanchnic nn.
. Preganglionic fibers travel in autonomic plexuses on aorta to reach sup. And inf. Mesenteric ganglia to synapse
. Postganglionic fibers course in autonomic plexuses on branches of sup. And inf. Mesenteric aa. To organs
Sympathetic innervation of midgut only
. T10/11 go through white rami then leave w/o synpasing in lesser thoracic splanchnic n.
. Pierces diaphragm and enters abdomen
. Contribute to autonomic plexuses on aorta and course w/in autonomic plexuses to reach sup. Mesenteric ganglion (SMG) to synapse
. Postganglionic fibers leave SMG and course w/in autonomic plexuses on branches of sup. Mesenteric a. To organs
Sympathetic innervation of hindgut only
. T12 and L1-2/3
. Go to trunk via white rami, don’t synapse, leave in least thoracic (T12) and lumbar splanchnic (L1-3) nn.
. Course w/in autonomic plexuses on aorta to inf. Mesenteric ganglion to synapse
. Postganglionic fibers then course w/in autonomic plexuses on branches of inf. Mesenteric a. To organs
General parasympathetic pathway to abdominal viscera
. Preganglionic fibers from vagus Cranial n. 10)or pelvic splanchnic nn. (S2-4) called craniosacral outflow
. Vagus n. Provides preganglionic fibers to most of GI tract up to L colic flexure
. Pelvic splanchnic nn. Provide preganglionic fibers distal to L colic flexure
. Preganglionic fibers synapse in enteric ganglia w/in walls of each organ
. Postganglionic fibers course w/in walls of organ
general Parasympathetic pathway in abdomen up to L colic flexure
. Preganglionic neurons in R/L vagus nn. W/ cell bodies in brain
. Vagi form ant. And post. Trunks on esophagus
. Enter abdomen as plexuses on esophagus
. Convert preganglionic fibers to abdominal aortic autonomic plexuses that course along branches of aorta to target tissues
. Synapse in organ w/ cell bodies of terminal intrinsic/enteric) ganglia
. Short postganglionic in organ wall
General parasympathetic pathway for most of hindgut (distal to L colic flexure)
. Cell bodies in S2-4
. Leave ventral rami of S2-4 coursing w/in pelvic splanchnic nn.
. Pelvic splanchnic nn. Convey preganglionic fibers that synapse in enteric ganglia w/in walls of hindgut
. Short postganglionic fibers course w/in walls of organs
Visceral afferents
. Convey pain
. Course along sympathetic fibers but impulse goes in opposite direction
. Enters spinal cord at same level that sympathetic fibers exit spinal cord
. Cell bodies in DRG
. Pain referred to dermatomes assoc. w/ spinal cord level where afferent fibers communicate w/ spinal cord (levels assoc. w/ sympathetic fibers supplying viscera)