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!
GIP
From K cells, increases insulin and decreases acid
This is why enteral glucose increases insulin more than parenteral glucose
When are motilin levels greatest?
In fasting state
Carbohydrate Absorption
Glucose and Galactose by SGLT1
Fructose by GLUT5
All across basolateral membrane via GLUT2
Rate limiting step of bile acid synthesis?
Cholesterol 7-alpha-hydroxylase
What enzyme deficiency causes jaundice in infants?
UDP-Glycuronosyl Transferase
What gives urine its yellow color?
Urobilin (from urobilinogen in enterohepatic circulation)
Salivary Tumors
Pleomorphic: benign, mixed tumor
Mucoepidermal: malignant
Warthin: lymphoid, benign
3 types of infectious esophagitis
Candida: white pseudomembranes
CMV: linear ulcers
HSV: punched out lesions
Plummer Vinson Syndrome
Dysphagia, Iron Deficiency, Esophageal Webs
Cancers associated with H Pylori
MALT lymphoma (cured by H Pylori Treatment) Gastric
2 types of gastric cancer
Intestinal Type: H Pylori, smoked foods, tobacco, commonly on lesser curvature, ulcer w/ raised margins
Diffuse Type: signet ring cells, thickened stomach wall
Genetics Associated w/ Celiac
HLA-DQ2 HLA-DQ8
Pneumonic for Zenker
Elderly MIKE Elderly Males Inferior Pharyngeal Constrictor Killian Triangle Esophageal Dysmotility
Rule of 2s for Meckel
2x more likely in males 2 inches long 2 feet from ileocecal valve 2 years old 2 types of mucosa 2% of population
Causes of Intussusception
Meckel Divertuculum
Rotavirus Vaccine
Adenovirus
Peutz=Jeghers
Harmatomas, hyperpigmented skin
Lynch Syndrome Associated Cancer
GI, Ovarian, Endometrial, Skin
Strep Bovis Sepsis, what is the next step?
Colonoscopy
GGT tests
More specific than ALP for biliary disease (ALP can be elevated in bone disease)
Gilbert Syndrome
Reduced UDP-GT function, jaundice w/ stress, benign
Crigler Najjar Syndrome
Fatal, No UDP-GT function, high indirect bili
Dubin-Johnson Syndrome
Failure of bile transport into ducts, high conjugated bilirubin, black liver, benign
Rotor Syndrome
same as Dubin Johnson but no black liver
Hemochromatosis
HFE gene, Chr 6, HLA-A3
Prussian Blue distinguishes from Lipofuscin
Cirrhosis, DM, pigmented skin, cardiomyopathy, hypogonadism, arthropathy
Primary Sclerosis Cholangitis
Associated w/ UC. Men. Increased pANCA
Primary Biliary Cholangitis
Autoimmune, Women. Increased AMAs
Gallstones
Stasis, Increased Cholesterol/Bilirubin, Reduced Bile Salts