HTHSCI 1H06 B Lecture 15: GI Physiology: The Stomach Notes
22 Jun 2018
School
Department
Course
Professor
THE STOMACH
.
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Review of Deglutition
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Voluntary →take tongue ,put food to back of oral cavity Into oral pharynx
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Pharyngeal →pattern generators in brain SHM take over muscular contraction
(PWHLH upper airway by closing soft
palate
,protecting lower airway by closing
OH trachea w/ epiglottis
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Esophageal → relaxing esophageal sphincter to allow food to go by +par,stay ,
takes over to bring food through thoracic cage ,bringing it down to the lower
esophageal sphincter which relaxes to allow food to get into the stomach
The "Basic "Plan
•4layers :Mucosa
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epithelium
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lamina pwpria !glues epithelium to musculans mucosa ISM )
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mukulanl mucosa !told epithelium
Sub mucosa
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CT ,blood vessels ,nerves
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sub mucosal glands :glands that secrete mucous +dump it into alimentary canal ,lubricate food tdigest A
Muscular is
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inner circular →acts as sphincter +forms peristaltic contractors to get food from one end to the other
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Outer longitudinal
sewsa Adventitial
-mesothelinm :thin epithelium secreting serosal fluid to allow intestines +stomach to more around
-CTI thin )
the Enteric Nervous system
•ldett complete ,contained system in wall of alimentary canal
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has inputs + outputs to sc ,but can lunch on on its own
>Can generate own local reflexes
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peristalsis : al Hvnahng wares of muscle contraction and relaxation used to move food through the 41 tract
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100 + million neurons from esophagus to anus
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2components :
IMyehtlno plexus (between are . and long ,layers )→Muscular
Sub mucosal plexus (In sub mucosa )→epithelium +Sub mucosal glands
•Interstitial cells of Cajal :pacemakers
of the gut
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Parasympathetic can In rate of contractors
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Sympathetic can Iv rate of contractions
The ANS tENS Meet
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When thew food present it can either Cause stretch ,change in pH ,sensed by Hmong neurons in mulusal epithelium
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share into With sub mucosal plexus ,myenthi plexus to promote secretion to help with lubrication +promote mixing
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Sensory into is also shared with cns (Tdistention =pain →cerebral cortex )
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Motor neurons from my enteric plexus innervate longitudinal t circular muscles in gut wall helping coordinate peristaltic contraction
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Parasympathetic →can interact directly with myentenc plexus +sub mucosal plexus +can the the activities of speuhc segments
of the Gl tract
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sympathetic →can interact with myentenc plexus +sub mucosal plexus + can tblood How to GI halt by contract hg pre capillary
sphincters +putting everything to sleep
Sympathetic Innovation
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Thoran lumbar output
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para vertebral chain ganglia beside spinal Cord
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But ganglia supplying gut sit very close to the gut wall
>celiac ganglion →on celiac artery
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superior meHnHnc ganglion
>Inferior mesenteric ganglion
parasympathetic innervations
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turns everything up
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controlled by CNX (VAGW )→Innervated much of proximal and all distal components of alimentary Canal
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Stops at level of sigmoid colon Icontrolled by sacral output through splanchnic news )
