Notes in GI Physiology

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Status	Last Update	Fields
Published	01/20/2024	Location of Myenteric Plexus {{c1::Esophagus to anus -Between longitudinal andcircular SM layers}}
Published	01/20/2024	Function of Myenteric Plexus{{c1::controls GI motility}}
Published	01/20/2024	Submucosal Plexus location:{{c1::Mucosal layer from esophagus to anus }}
Published	01/20/2024	Function of Submucosal Plexus Local control• {{c1::Secretion}}• {{c1::Absorption}}• {{c1::Contraction of muscularis mucosa}}
Published	01/20/2024	Cranial division—(Vagus N.)—location: {{c1::first half of gut }}
Published	01/20/2024	Sacral division—(Pelvic N.)—location: {{c1::second half of gut }}
Published	01/20/2024	What does the parasympathetic innervation excite?The {{c1::ENS}}
Published	01/20/2024	Sympathetic Innervation of ENS:Preganglionic Neurons (long)—Originate at {{c1::T5-L2}} (cell bodies). Synapse in {{c1::prevertebral ganglia }}
Published	01/20/2024	Postganglionic Neurons (long)Originate in {{c1::ganglia (cell bodies)}} -Innervate entire gut. Terminate in ENS (mostly)
Published	01/20/2024	Postganglionic efferent neurons- PNS—{{c1::acetylcholine}}SNS—{{c1::norepinephrine}}
Published	01/20/2024	Enteric nervous systemExcitatory—{{c1::acetylcholine, substance P, serotonin -}}Inhibitory—{{c2::VIP, NO}}
Published	01/20/2024	Stimulation of afferent neurons by:Distention of gut wall -Nonspecific {{c1::irritation}} of gut mucosaSpecific chemical stimuli
Published	01/20/2024	Local Gastrointestinal Reflexes (within ENS) -Afferent fibers from gut terminate in {{c1::ENS}}Affect (+ or −)secretion, peristalsis,mixing movem…
Published	01/20/2024	ParacrinesSome are peptides ({{c1::somatostatin}}), some are not ({{c1::histamine}}).
Published	01/20/2024	{{c1::Gastrin}} and {{c1::CCK}}-5 C-terminal AA identical -Produce all effects of each other at high doses
Published	01/20/2024	Names for GI Peptides {{c1::Secretin, GIP, VIP, glucagon}}-Some effects are shared.
Published	01/20/2024	Response to meal-Large amounts of {{c1::G-17}} released from antrum -Small amounts of {{c1::G-34}} released from duodenum
Published	01/20/2024	Where are gastrin cells released from? G cells in {{c1::antrum}} and {{c1::duodenuM}}
Published	01/20/2024	What will inhibit gastrin release? {{c1::acidification of antrum}}
Published	01/20/2024	Stimuli for Gastrin release:protein digestion products— nervous, physical distention — ({{c1::calcium, regular & decaf coffee, and wine}})
Published	01/20/2024	Gastric acid secretion-1,500× more potent than {{c1::histamine}}
Published	01/20/2024	Gastrin will stimulate growth of {{c1::oxyntic mucosa}} of the stomach, the duodenal mucosa, and colon mucosa
Published	01/20/2024	Patients with gastrin-secreting tumors have {{c1::mucosal hyperplasia}} and hypertrophy.
Published	01/20/2024	Symptoms of ZES{{c1::Duodenal ulcers, diarrhea, steatorrhea, hypokalemia}}
Published	01/20/2024	Hypergastrinemia causes hypersecretion of {{c1::acid}}
Published	01/20/2024	What cell mass increases with hypergastrinemia?{{c1::Parietal cell mass }}
Published	01/20/2024	There is constant stimulation of what mucosa in hypergastrinemia? {{c1::Hyperplastic}} mucosa
Published	01/20/2024	The low pH that occurs in Gastrinoma inactivates {{c1::pancreatic lipase}} and causes bile salts to precipitate. The result is steatorrhea
Published	01/20/2024	Hypokalemia results from loss of {{c1::GI secretions}} in stool
Published	01/20/2024	{{c1::ChiRhoStim® (synthetic secretin)}}: Is the mostsensitive and accurate diagnostic method forgastrinoma.
Published	01/20/2024	A simple {{c1::blood test}} can be performed in an officesetting which reliably differentiates patients withgastrinomas and peptic ulcer disease, even…
Published	01/20/2024	Any increase in serum gastrin concentration greaterthan {{c1::110}} pg/mL above baseline followingadministration of ChiRhoStim (secretin) isdiagnostic…
Published	01/20/2024	{{c1::Secretin}} inhibits gastrin release from normal G-cells, but stimulates gastrin release from tumor cells
Published	01/20/2024	{{c1::CCK}} is the principle stimulus for delivery of pancreatic enzymes and bile into small intestine
Published	01/20/2024	Where are secretin cells released from? {{c1::S-cells of duodenal mucosa }}
Published	01/20/2024	Stimuli for release of secretin:{{c1::Acid}} in duodenum and jejunum (pH <4.5) (small amounts can be released from ileum) {{c1::Fatty aci…
Published	01/20/2024	Physiological effects of secretin:{{c1::Nature’s Anti-acid }}Inhibits gastrin release as well as gastric acid secretion(enterogastrone) Stim…
Published	01/20/2024	GIP physiological effect:Inhibits {{c1::gastric acid secretion (enterogastrone)}}
Published	01/20/2024	Long loop Reflex- Gut → Aff. N. →{{c1::prevertebral ganglia}} →Eff. N. → gut
Published	01/20/2024	What reflexes use long loop?{{c1::gastrocolic, enterogastric, colonoileal}}
Published	01/20/2024	Vagovagal reflexes- Stomach/duodenum → Aff. N. → brain stem → Eff.N. → stomach/duodenum - Controls {{c1::gastric motor}} and {{c1::secretory ac…
Published	01/20/2024	Defecation reflexes- Colon/rectum → Aff. N. → {{c1::spinal cord}} → Eff. N.→ colon/rectum
Published	01/20/2024	Pain Reflexes—overall {{c1::inhibition of GI tract}}
Published	01/20/2024	GIP is released from K-cells of {{c1::duodenum}} and {{c1::proximal jejunum }}
Published	01/20/2024	What kind of glucose stimulates GIP? {{c1::Oral}}
Published	01/20/2024	Effects of GIPInhibits {{c1::gastric acid secretion (enterogastrone)}}
Published	01/20/2024	What does GIP stimulate?{{c1::Insulin release }}
Published	01/20/2024	What is motilin released from? M-cells of {{c1::duodenum}} and {{c1:: proximal jejunum}} during fasting at 100 min intervals
Published	01/20/2024	What controls motilin release?{{c1::neural control (acid and fat can alsocause small amounts to be released)}}
Published	01/20/2024	What does motilin stimulate?{{c1::Upper GI motility}}
Published	01/20/2024	Where is somatostatin found?{{c1::gastric/duodenal mucosa and pancreas }}
Published	01/20/2024	Release of somatostatin is stimulated by… but inhibited by..{{c1::Acid / Ach}}
Published	01/20/2024	What does somatostatin inhibit release of?{{c1::All gut hormones }}
Published	01/20/2024	What does somatostatin directly inhibit?{{c1::Parietal cell acid secretion }}
Published	01/20/2024	What does somatostatin mediate?Acid-induced inhibition of {{c1::gastrin}} release
Published	01/20/2024	What causes release of histamine?{{c1::Gastrin/Ach}}
Published	01/20/2024	What does histamine stimulate?{{c1::Acid secretion}}
Published	01/20/2024	Name two histamine receptor blockers that decrease acid secretion?{{c1::Cimetidine and Ranitidine}}
Published	01/20/2024	{{c1::Syncytium}}—nucleated mass ofprotoplasm produced by mergingof cells
Published	01/20/2024	The slow waves usually do not by themselves cause muscle contraction in most parts of GI, except in the {{c1::stomach}}.
Published	01/20/2024	Rhythmical changes (oscillating depolarization and repolarization) in membrane potential caused by variations in {{c1::calcium}} or {{c1::sodium}} con…
Published	01/20/2024	Fixed frequency determines {{c1::maximum frequency}} of SM contractions
Published	01/20/2024	Variable amplitude is affected by {{c1::nervous/hormonal}} stimuli
Published	01/20/2024	What are spike potentials?True action potentials that occur when slow waves {{c1::reach threshold }}
Published	01/20/2024	What do spike potentials cause?{{c1::SM contraction }}
Published	01/20/2024	Stimulation of spike waves by{{c1::Stretch, actelycvholine, parasympathetics }}
Published	01/20/2024	What has the lowest slow waves? The highest?{{c1::Stomach is lowest, the duodenum is the highest }}
Published	01/20/2024	What is the depolarization phase of slow waves caused by?The repolarizing phase?Depolarization: {{c1::Ca2+ inward current }}Repolarization: {{c1:…
Published	01/20/2024	In stomach smooth muscle, even {{c1::subthreshold}} slowwaves produce a weak contraction and exhibits tonic contractions
Published	01/20/2024	What are the three big gastrointestinal movements?{{c1::PeristalsisRhythmic segmentationThe migrating motor complex (MMC)}}
Published	01/20/2024	In contrast to skeletal muscle (where each action potential is followed by a separate contraction or twitch), in smooth muscleindividual action potent…
Published	01/20/2024	Stimuli that initiate peristalsis- {{c1::Distention}} - orad contraction with downstream receptive relaxation =“Law of the Gut” - Irritation of g…
Published	01/20/2024	Plexus required for peristalsis:{{c1::Myenteric }}
Published	01/20/2024	What decreases peristalsis and blocks Ach?{{c1::Atropine}}
Published	01/20/2024	{{c1::Hirschsprung}} disease - Congenital absence of plexus
Published	01/20/2024	Two types of secretion- Serous—Watery secretion, contains an {{c1::alpha-amylase}} and {{c1::lingual lipase}}- Mucous—Contains {{c1::mucin glycop…
Published	01/20/2024	What sphincter relaxes during the first part of the swallowing reflex?{{c1::The esophageal sphincter }}
Published	01/20/2024	What triggers peristalis? {{c1::When the bolus stretches the esophagus }}
Published	01/20/2024	What sphinter relxases during step 3-4 of the swallowing reflex?{{c1::The lower esophageal}} sphincter
Published	01/20/2024	Swallowing center also initiates relaxation of {{c1::stomach smooth muscle}}
Published	01/20/2024	If necessary, {{c1::secondary peristalsis wave(s)}} comes to move bolus into stomach
Published	01/20/2024	Primary peristalsis:- Continuation of pharyngeal peristalsis- Coordinated by swallowing center- Cannot occur after {{c1::vagotomy}}
Published	01/20/2024	• Upper esophagus—upper 1/3 is {{c1::striated muscle}}• Lower esophagus—lower 2/3 is {{c1::SM}}
Published	01/20/2024	Secondary peristalsis:- Induced by distension/repeats until bolus is cleared.- {{c1::Stretch}} related afferent sensory input to ENS andswallowing cen…
Published	01/20/2024	Between Swallows- High pressure at sphincters- Pressure in esophageal body about equal to {{c1::intrapleural pressure}}
Published	01/20/2024	During Swallowing- UES relaxes—({{c1::low}} pressure)- Peristaltic wave—({{c1::high}} pressure)- LES and fundus relax—receptive relaxation (lowpressur…
Published	01/20/2024	Ach is excitatory neurotransmitter that stimulatescontraction (acts at {{c1::muscarinic}} receptor)
Published	01/20/2024	{{c1::Barrett’s esophagus}}.—a precancerous condition. Results fromesophageal cells ‘changing’ in response toconstant acid exposure; this can lead toa…
Published	01/20/2024	{{c1::Achalasia}} - a rare disorder that makes it difficult for food and liquid to pass from the swallowing tube connecting your mouth and stomac…
Status	Last Update	Fields