Visceral Innervation Flashcards
(44 cards)
Neurons in visceral motor pathway
. Pre-ganglionic neuron and post-ganglionic neuron
Pre-ganglionic neuronal cell bodies for visceral motor
. Located in ventro-lateral horns at specific spinal cord levels
. T1-L2 levels for sympathetic neurons
. S2-4 levels for parasympathetic neurons
Preganglionic visceral motor fibers/axons
. Ventral roots
Post-ganglionic neuronal cell bodies for visceral motor nerves
. Autonomic ganglia outside CNS
Parasympathetic division
. Conserve energy and promote normal function
. Localized target and effects
. Both pre and post-ganglionic neurons release neurotransmittter Ach (cholinergic)
. Cell bodies of pre-ganglionic neurons in gray matter of brain stem (vagus) and sacral spinal cord segments (S2-4, craniosacral outflow)
Sympathetic division
. Prepare fight/flight
. Multiple targets and board effects
. Pre-ganglionic neurons release Ach and post-ganglionic neurons release NE(adrenergic)
. Cell bodies of pre-ganglionic neurons in gray matter of thoracic and lumbar spinal cord segments (T1-L3, thoracolumbar outtflow)
Enteric division
. Intrinsic innervation of GI tract located w/in GI walls
.2 complex and interconnected plexuses (meissner and Auerbach)
. 3rd ANS division or parasympathetic component
. Neurons capable of autonomous generation of peristalsis and glandular secretions
. Neurons receive input from parasympathetic and sympathetic divisions
Parasympathetic pre-ganglionic cell body locations
. Brainstorm nuclei assoc. w/ cranial nerve III, VII, IX, and X
. Ventro-lateral horns of gray matter in sacral spinal cord segments S2-4
Route of pre-ganglionic axons coursing in vagus nerve
. In thorax: pre-ganglionic fibers join pulmonary,cardiac, and esophageal autonomic plexuses to distribute to terminal ganglia in walls of lungs, heart, and esophagus
. Esophageal plexus coalesces into ant. And post. Vagal trunks that continue into abdominal cavity
.abdomen: pre-ganglionic fibers (vagal trunks) enter autonomic plexuses assoc. w/ abdominal aorta and branches
. Continues along blood vessels to terminal ganglia in wall of stomach, liver, pancreas, SI, and ascending and transverse colon
Autonomic plexuses
. Bundles of sympathetic, parasympathetic, and visceral sensory fibers coursing to/form common structures
. Named for structures they supply or where they’re located
Route of pre-ganglionic axons/fibers arising in sacral spinal cord segments
. Pre-ganglionic fibers exit S2-4 via ventral roots, spinal nerve proper, and ventral rami
. Branch from ventral rami as pelvic splanchnic nn. That pass to inf. Hypogastric plexuses ain’t hen to sub-plexus specific to pelvic viscera
. Post-ganglion cell bodies: near or w/in walls of target organs
. Post-ganglionic neurons have short axons compared to post-ganglionic sympathetic neurons
T/F There is no parasympathetic n. Distribution to limbs or body wall
T, only supply viscera of head, neck, thorax, abdomen, and pelvis
Splanchnic nerves
. Convey visceral motor and sensory fibers to and from viscera
. Can be parasympathetic or sympathetic
Pre-ganglionic cell body location in sympathetic division
. . Ventro-lateral horns of gray matter is spinal cord segments T1-L2/3 only
Post-ganglionic cell bodies in sympathetic division
. Chain ganglia (paravertebral ganglia): linked by sympathetic fibers to form sympathetic trunks/chains that run along spinal column
. Pre-vertebral ganglia: abdomen and pelvis along abdominal aorta and branches
Pre-vertebral ganglia
. Celiac ganglion: celiac trunk artery and innervates foregut structures
. Sup. Mesenteric, aorticorenal, and inf. Mesenteric ganglia
Route of pre-ganglionic sympathetic fibers
. Exit spinal cord via ventral roots, spinal nerve proper, and ventral rami
. Split as white rami communicantes and enter sympathetic chain (T1-L2/3 only)
Routes w/in sympathetic chain
. Synapse w/ post-ganglionic neuron in chain ganglion at level of entry or course sup/inf. To synapse w/ post-ganglionic neuron in a chain ganglion at different level
. Pass through chain w/o synapsids and merge from chain as thoracic splanchnic nn (T5-12) or lumbarbsplanchnic nn (L1-3) in abdominal cavity, fibers then synapse in pre-vertebral ganglia
Sacral sympathetic splanchnic nn branch fro, chain in pelvic cavity, but _____
Fibers primarily post-ganglionic
sympathetic post-ganglionic fibers
. Long w high number collateral branches for more diffuse widespread effect
Post-ganglion sympathetic fibers in body wall and limbs
. Exit chain as gray rami communicantes (assoc. w/ all spinal nn.)and re-enter spinal nerve proper
. Course w/ dorsal and ventral rami of spinal nn. To their targets
Post-ganglionic sympathetic fibers in head and neck
. Branch directly from sup. Cervical ganglia
. Course along branches of external carotid a. To their targets
Post-ganglionic sympathetic fibers in thoracic organs
. Heart and lungs: split from lower cervical and upper thoracic chain ganglia as sympathetic cardiac nn. And enter cardiac and pulmonary autonomic plexuses to innervates heart and lungs
. Esophagus: split from thoracic chain ganglia and contributes to esophageal autonomic plexus
Post-ganglionic sympahtetic fibers in abdominopelvic viscera
. Arise from prevertebral ganglia and course along blood vessels and through autonomic plexuses to reach target organs
