GI Stuffs Flashcards
Embryology of GI tract: Sections
Foregut: Esophagus to upper duodenum
Midgut: Lower duodenum to 2/3 of transverse colon
Hindgut: Distal 1/3 transverse colon to rectum
When does herniation and rotation occur in development?
6th week Herniation
10th week rotation (270 degrees)
Gastrochesis vs Omphalocele
Gastrochesis: failure of folds, intestines herniate w/o covering
Omphalocele: persistent physiologic herniation, has peritoneal covering
Teratogen associated w/ pyloric stenosis
Macrolides
Retroperitoneal Structures:
SADPUCKER: Suprarenals (adrenals) Aorta Duodenum (2-4) Pancreas (head and body) Ureters Colon (ascending and descending) Kidneys Esophagus Rectum
What attaches liver to anterior body wall?
What does it contain?
Falciform Ligament Ligamentum Teres (remnant of umbilical vein)
What ligament has portal triad?
Hepatoduodenal, forms entry to lesser pouch
Splenorenal Ligament
Attaches spleen to posterior body wall, contains splenic artery/vein and tail of pancreas
Two nerve plexuses in gut tube
Meissner’s: submucosa, fluid secretion
Myenteric (Aurbachs): Muscularis Mucosa, Motility
Histologic Features Distinguishing Duodenum, Jejunum and Ileum
Duodenum: Brunner’s Glands (HCO3)
Jejunum: Plicae Circularis
Ileum: Peyer Patches
All have: crypts of Liberkuhn, and Goblet cells
Rough levels of major abdominal arteries
Celiac: T12
SMA: L1
IMA: L3
Bifurcation: L4-L5
Layers of the Inguinal Canal (Inner to Outer)
Transversalis Fascia (Internal spermatic fascia) Transversalis Muscle (cremasteric muscle) External Oblique Fascia (external spermatic fascia)
Miss Internal Oblique
What causes indirect inguinal hernia?
Failure of processus vaginalis to close
Can cause hydrocele
Vessels that demarcate direct and indirect hernias
Epigastrics (indirect is lateral, direct is medial)
What hormone causes gastric hyperplasia?
Gastrin (increases w/ chronic PPIs)
What cells secrete Cholecystokinin?
I cells (duodenum and Jejunum)
Secretin
From S cells, increase pancreatic HCO3 and bile; REDUCES acid secretion!