Flashcards in GI Review Deck (9)
Layers of GI luman (deep to surface)
• Mucosa (w/ circular folds, mucosal galnds, mucosal epithelium with lamina propria)
• Submucosa (artery, veins, lymph vessels follow into circular folds)
• Muscularis externa (circular, then longitudinal muscle layer)
• Serosa (visceral peritoneum)
3 factors influencing digestion
• Local factors (pressure from volume, chemicals, pH)
• CNS- myenteric reflexs (the long game of peristalsis)
• Hormonal control
3 parts of small intestine
• Duodenum- “mixing bowl”, receives chime, 25cm
• Jejunum- bulk of chemical digestion and nutrients absoption 2.5m long
• Ileum- final small intestine section 3m
What produces bile?
- About a liter a day
- Closely linked to bilirubin production from break down of RBC in liver
What stores bile and what stimulates its release?
Stored in Gallbladder and released when CCK hormone (from duodenum) stimulates contraction. Flows down cystic duct to common bile duct and released into duodenum.
Three key bits of Mesentery?
• Lesser omentum- between stomach and liver
• Falciform- stabilizes liver relative to diaphragm and abd wall
• Greater omentum- hangs from stomach anteriorly
What are mesenteries and why are they there?
• Are double sheets of the peritoneal membrane.
• Stabilize postions of attached organs, preventing entanglement of intestines
• Provide route to digestive tract for blood vessels, lymph and nerves
Two layers of the peritoneum?
What kind of membrane? And what service does it provide?
parietal- inner surface of body wall
visceral- encloses enclosed organs of the abdominopelvic cavity.
Serous membrane allows organs to slide across one another without damage to themselves or walls of the cavity.