Lecture 34: Visceral Nervous System of Abdomen Flashcards
sympathetic: 3 pathways/destinations
-to body wall
-body wall cranial to diaphragm
-body wall caudal to diaphragm
parasympathetic: 3 pathways/destination
-head and neck
-body caudal to neck (thorax, foregut, midgut)
-hindgut and pelvis
what nerve is preganglionic
vagus
what pathways does pain follow
sympathetic
structure –> spinal nerve –> dorsal root ganglion
what pathway does non pain follow
parasympathetic to brain
where does vagus end
end of midgut
foregut: structures (6)
-esophagus
-stomach
-proximal duodenum and pancreas
-liver
-gallbladder
midgut structures (6)
-distal duodenum and pancreas
-jejunum
-ileum
-cecum
-ascending colon
-proximal 2/3 transverse colon
hindgut: structures (5)
-distal 1/3 transverse colon
-descending colon
-sigmoid colon
-rectum
-proximal anal canal
role of sympathetics in abdomen
restrict blood flow/vasoconstriction to inhibit action of organ = slow down digestion
what 2 ways can smooth muscle contraction be inhibited
-sympathetic nerve fibers directly
-enteric nervous system
origination of preganglionic sympathetics in abdomen
T5-L4
origination of preganglionic sympathetics in abdomen
T1-L4
what nerves attach to T5 to coccygeal paravertebral ganglia in abdomen
abdominopelvic splanchnic nerves
3 paravertebral ganglia where AP splanchnic nerve can synpase
-celiac
-cranial mesenteric
-caudal mesenteric
paravertebral ganglia aka
preaortic ganglia
where are celiac, cranial mesenteric and caudal mesenteric ganglia located
abdominal aorta
periarterial plexus
synapse occurs at aorta
preganglionics wrap around artery to travel
how do sympathetic postganglionic fibers travel after synapsing at celiac/cranial mesenteric/caudal mesenteric
periarterial plexuses to target organ
where does hindgut begin
2/3 along transverse colon
role of parasympathetics in abdomen
-stimulate abdominal organs
-stimulate contraction of smooth muscle, secretory cells, gland cells
preganglionic parasympathetic axons travel to body via (2)
vagus nerve
perarterial plexuses
where do parasympathetic axons synapse
wall of target organ
parasympathetic preganglionic cell body found in
brain
where does lateral horn end
L4
what structure does vagal trunks have to travel through to get to abdomen
esophageal hiatus
location of perganglionic parasympathetic cell bodies destined for HINDGUT and PELVIC organs
spinal cord anterior horn at S2, S3 and S4
what nerves are branches of ventral rami
pelvic splanchnic nerves
pathway of preganglionic parasympathetics
lateral/anterior horn –> ventral root –> mixed spinal nerve –> ventral ramus –> pelvic splanchnic nerve
what are the sympathetic abdominopelvic nerves
sacral splanchnic nerves
pelvic and sacral splanchnic nerves originate from
abdominopelvic splanchnic nerves
when do abdominopelvic splanchnic nerves renamed to sacral/pelvic splanchnic nerves (what spinal cord level)
S1
pelvic splanchin nerves: sympathetic or parasympathetic?
parasympathetic
sacral splanchnic nerves: sympathetic or parasympathetic?
sympathetic
visceral pain only occurs from what levels
T1-L4
where does referred pain mix up occur
dorsal horn
3 cell bodies in dorsal root ganglion of S2, S3 and S4
somatic sensory
pain
nonpain
non pain pathway: hindgut
parasympathetic
organ –> plexus –> pelvic splanchnic nerves –> ventral ramus –> mixed spinal nerve –> DSG –> dorsal root –> dorsal horn
pain pathway: foregut and midgut
sympathetic
organ –> plexus –> paravertebral ganglion NO synapse –> white ramus communicans –> mixed spinal nerve –> DSG –> dorsal root –> dorsal horn
enteric nervous system: definition, location, function
-separate component of ANS for regulating GI tract
-local reflex response with afferent and efferent neurons (plexuses)
-located in wall of GI (esophagus to rectum)
2 plexuses in enteric NS
-myenteric/auerbach’s plexus
-submucosal/meissner’s plexus
myenteric/auerbach’s plexus: location
between circular and longitudinal layers of smooth muscle in GI tract
submucosal/meissner’s plexus: location
submucosa of GI tract
parasympathetic: enteric nervous system (function)
stimulate smooth muscle contraction (peristalsis) and glandular secretions
sympathetic: enteric NS (function)
-inhibit smooth muscle contraction/peristalsis
-vasoconstriction
enteric NS: reflex control of GI
Sensory neurons: perceive distension caused by bolus
At the same time: Stimulate interneurons distal to bolus to relax AND Stimulate interneurons proximal to bolus to contract
Continuous contraction proximal to bolus pushes bolus along
hirschprung’s disease: definition, cause, effects
-congenital megacolon
-failure of neural crest migration to form enteric NS
-distal colon can’t generate peristalsis –> fecal matter accumulates in proximal colon –> colon enlarges
