GI anatomy

lilyo's version from 2016-06-02 05:02


Question Answer
Duodenal atresiafailure to recanalize --> double bubble sign on x-ray, associated with Down syndrome
jejunal and ileal atresiadisruption of mesenteric vessels --> ischemic necrosis --> segmental resoprtion (bowel discontinuity or "apple peel")
hypertrophic pyloric stenosispalpable "olive" mass in epigastric region and nonbilious projectile vomiting, results in hypokalemic hypochloremic metabolic alkalosis
annular pancreasventral pancreatic bud abnormally encircles 2nd part of duodenum --> duodenula narrowing
pancreas divisumventral and dorsal parts fail to fuse at 8 weeks
spleen embryologyarises in mesentery (--> mesodermal) but has foregut supply (celiac trunk --> splenic artery)
retroperitoneal structuressuprarenal (adrenal) glands, aorta and IVC, duodenum (parts 2-4), pancreas, ureters, colon (descending and ascending), kidneys, esophagus, rectum (SAD PUCKER)
layers of gut wallmucosa, submucosa (includes Meissner plexus), muscularis externa (includes myenteric/Auerbach plexus), serosa (or adventitia when retroperitoneal)
erosion vs ulcererosion only in mucosa, ulcer extends into submucosa
esophagus histologynonkeratinized stratified squamous epithelium
stomachgastric glands
duodenumvilli and microvilli increase absorptive surface
jejunumplicae circulares and crypts of Lieberkuhn
ileumpEyer patches, largest number of goblet cells in small intestine
coloncrypts of Lieberkuhn but no villi, abundant goblet cells
foregut blood supply + innervationceliac + vagus
midgut blood supply + innervationSMA + vagus
hindgut blood supply + innervationIMA + pelvic
internal hemorrhoids venous drainagesuperior rectal vein --> inferior mesenteric vein --> portal system
internal hemorrhoids lymphatic drainageinternal iliac lymph nodes
external hemorrhoids venous drainageinferior rectal --> internal pudendal --> internal iliac --> common iliac --> IVC
external hemorrhoids lymphatic drainagesuperficial inguinal nodes
anal fissure locationbelow pectinate line, posterior
Hepatic stellate (Ito) cellsin space of Disse, store vitamin A (when quiescent), produce extracellular matrix (when activated)
Zone I of liveraffected 1st by viral hepatitis, ingested toxin (eg cocaine)
Zone II of liveryellow fever
Zone III of liverpericentral vein, affected 1st by ischemia, contains cyP450 system, most sensitive to metabolic toxins, site of alcoholic hepatitis
indirect inguinal herniagoes through internal inguinal ring, external inguinal ring, into scrotum, occurs in infants due to failure of processus vaginalis to close, lateral to inferior epigastric vessels
direct inguinal herniaprotrudes through inguinal triangle, usually in older men, medial to inferior epigastric vessels