Histology - GI System Flashcards
Replace all cell types
Stem cells (in isthmus)
parts of GI tract with submucosal glands
duodenum, esophagus
Stomach - ELSMS/A
E: simple columnar LP: fundic, cardiac, pyloric glands SM: rugae ME: inner oblique, middle circular, outer longitundinal. S/A: serosa
Small Intestine - ELSMS/A
E: simple columnae LP: vili, intestinal glands, Peyer’s patches (ileum). SM: circular folds, Brunner’s glands. ME: inner circular, outer longitunindal. S/A: serosa (except duodenum)
apical, small intestine. Antimicrobial secretions that regulate gut flora.
Paneth cells
HCl: lowers pH. Intrinsic factor: B12 absorption
Parietal cells
Smooth Muscle Sphincter Layer
Muscularis Externa
lymphatic capillaries, uptake chylomicrons (modified triglycerides)
Lacteals
Transition from simple columnar to stratified columnar to stratified squamous non keratinized
Rectoanal junction
Pepsinogen: converted to pepsin by low pH, digests protein
Chief cells
Esophagus - ELSMS/A
E: Stratified squamous non-keratinized LP: esophageal cardiac glands (lower) SM: esophageal glands ME: skeletal (upper) -> sk & sm (middle) -> smooth (lower) S/A: Adventitia
Secrete hormones like gastrin, CCK, secretin. Regulate gastric, intestinal, pancreatic, gallbladder activity -G cells, I cells, S cells, etc.
Enteroendocrine cells
antigen transport cells, phagocytizes antigen & transports it to lamina propria
M cells
Soluble mucus: lubrication
Mucous neck cells
Large Intesting - ELSMS/A
E: simple columnar. LP: intestinal glands. SM: - ME: inner circular, outer longintudinal (teniae coli). S/A: serosa in transverse and sigmoid. Adventitia in the rest.
submucosal glands
Esophageal glands, Brunner’s Glands (duodenum)
Lacteals, fenestrated capillaries, smooth muscle, GALT
Villus lamina propria components
cells found in the follicle-associated epithelium of the Peyer’s patch that transportantigens from the gut lumen to immune cells across the epithelial barrier, and thus are important in stimulating mucosal immunity.
M cells (or microfold cells) are
permanent infolds of the lamina propria
Intestinal glands
Insoluble mucus: barrier
Surface mucous cells
Gut mucosal immunology
- M cells phagocytize antigen and transport ot LP. 2. Immune cells in GALT activate plasma cells. 3. Plasma cells secrete antibodies that are transported to the lumen.
outer layer of adventitia
distal duodenum, esophagus, ascending and descending colon, rectum
goblet cells secrete mucus for lubrication & protection
Intestinal glands
cytoplasmic folds on enterocytes
Microvilli
LARGE INTESTINE functions
absorbs electrolytes & water, eliminates waste
Enterocytes, Goblet Cells
Villus epithelium components
Fundic Glands
surface mucous cels, stem cells, mucous neck cells, parietal cells, chief cells, enteroendocrine cells
Stratified squamous non-keratinized to statified squamous keratinized at anus. Internal anal sphincter is smooth muscle while external anal canal is skeletal muscle.
Anal canal
permanent outfolds of the lamina propria
Villi
permanent folds of submucosa
Circular folds (plicae circulares)
LARGE INTESTINE unique features.
Simple columnar epithelium, intestinal glands in LP, teniae coli in outerlongitudinal layer
