Chapter 22

jennraq2u's version from 2015-10-21 02:30


Question Answer
alimentary canal (GI) tract (digests+absorbs)or gut is continous muscular tube winds thru body: mouth 2 anus
accessory digestive organsteeth, tongue, gallblader, # of large digestive gladns=salivary/liver/pancreas
ingestiontaking food into digestive tract; usally via mouth
propulsionmoves food thru alimentary canal (r/t swallowing and peristalsis
peristalsisalternating waves of CTX & relaxation of muscles in organ walls
mechanical breakdownchewing/mixing food w/saliva@ tongue/churning food stomach&segmentation
segmentationrhytmic local constrictions of SI; makes absorption more efficient
digestioncatabolic steps r/t enzymes secreted @lumen of GI breakdown complex food
absorpitonpassage of digested end products @lumen of GI 2 mucosal cell2 blood/lymph
6 Activites of DIgestive ProcessIngestion*Propulsion*Mechanical Breakdown*Digestion*Absoption*Defecation
gut brainenteric nerve plexuses regulates digestive activity all along(covers) GI tract
visceral peritoneum covers externalsurfaces of digestive organs & continous w/ parietal periotneum
parietal peritoneumlines the body wall
peritoneal cavity slitlike space;containg serous fluid that lubricates digestive organs=glide side by side
mesentary(usally dorsal) sheet of 2 fused serous membranes;provides routes 4 BV,lymphatics/nerves->viscera; anchors organs;stores fat
retroperitoneal organs (behind)most of pancreas, duodenum (1st pt of SI), & pts of LI
intraperitoneal/peritoneal organsdigestive organs that keep their mesentary & remain in peritoneal cavity
splanchnic circulation= arteries that branch off abdominal aorta 2 serve digestive organs/hepatic portal ciruclaiton
mucous membrane function majorSecrete/Absorb/Protect p. 746
enteric neuronsin house nerve supply;comm & reg digestion; constitute bulk of 2 major intrinsic nerve plexuses
enteric nervous system linked to CNS byafferent visceral fibers & sympathetic/parasympathetic branches of ANS
serous cellsmake watery secretions w/ enzymes/ions & mucin
dental formulashorthand way r/t #s & relative positions of diff't types of teeth
salvitatory nucleiin brain stem (pons & medulla) r/t PNS & facial (VII) & glosspharyngeal(IX)
Mouth(1)INgests(2)begins mechanical breakdown r/t chewing (3)propulsion r/t swallowing (4) starts breakdwon/digestion
degulttionswallowing (2 phases=buccal =voluntary & pharyngeal-esophogeal phase=involuntary)
mucosal barriercoating of bicarbonate*epithelial cells w/ tight junctions*damaged mucosal cells recycled quick
cephalic phaseoccurs b4 food enters stomach; conditioned reflex r/t sight/smell etc
gastric phaseonce food reaches stomach this phase is started by neural/hormonal; distention & gastrin/gcells stimulate; SNS triggers inhibit
g cellsgastrin-secreting enteroendocrine cells
alkaline tideblood draining from the stomach is more alkaline than blood serving it
intestinal phase1)stimulatory 2)inhibitory=enterogastric reflex (p.765)
entogastric reflex1)Inhibit vagal nuclei(2)inhibit local reflexes(3)activate sympathetic fibers=pyloric sphincter 2 tighten
recpetive relaxationin anticipation & response 2 food moving thru; vagus nerves acting on serotonin
gastric accomodationex of smooth muscle plascity; visceral smooth msucle way of stress-relaxation response; stretch w/o greatly increasing tension
basic electrical rhythmpacemaker cells deplarize & repolarize sontanousely 3x p/min (cyclic slow waves)
emetic centermedulla where bloodborne molecules stream to prior to vomiting
HCL is lost in vomitous the blood becomesAlkaline as the stomach tries to replace its lost acid
portal triadBranch of heaptic artery* Branch of heaptic portal vein * A Bile Duct (p.773)
stellate macrophages/heaptic macrophagesremove debris/bacteria/worn out blood cells from blood as it flows past
hepatocytes functionprocess bloodborne nutrients* store fat-soluble vit* Important Detox of ammonia->urea
enterohepatic ciruclationbilea salts 1) reabsorbed in blood by ileum 2)Returned 2 liver via hepatic portal blood 3)resecreted in newly formed bile
cholecytokinincauses GB to Ctx; 1) Stimulates secretion of pancreatic juice (2) relaxes heaptopancratic sphincter so that bile/pancratic juice ->duoenum
migrating motor complexpatter on persistaltic wave activity @ duodenum along intestine to ileum
gastroileal reflexlong; triggered by stomach activity; increases force of segmentation/relaxes sphincter (p. 778)
2 mechanisms relax ileocecal sphincter1)gastroileal reflex (2)gastrin released by stomach increases motility of ileum/relaxes ileocecal sphincter
bacterial floracolonize colon*Syntehsize B complex*Metabolize mucin,etc*Ferment indigestable Carbs
digestionbreaks down food into monomers
hydroloysisenzymatic breakdwon of food+H20
monosaccharidesmonomers of Carbs
major absorptive role of ileumreclaim bile salts 2 recycle back 2 liver 4 resecretion
micellesfatty elemtns clustered 2gther w/ bile salts