Small intestine Flashcards
What are the secretions of the S.I?
- Mucus - from Brunner’s gland in duodenal mucosa
- Water - intestinal epithelium secretes Na+, Cl- & HCO3- into lumen & water follows
- Hormones - motilin, VIP, GIP, CCK, secretin
What digestive processes occur in the duodenum & proximal jejunum?
- Fat digestion - by pancreatic lipase to monoglyceride + fatty acids
- Starch digestion - by pancreatic amylase
- Protein break down - to peptide fragments by trypsin + chymotrypsin
What is absorbed in the S.I?
Calcium, iron & vitamins
How can malabsorption arise?
Failure/deficiency in
- pancreatic enzyme secretion
- absorption
- brush border enzymes
- bile secretion
What are symptoms of malabsorption?
Weight loss, abdo distension, diarrhoea, steatorrhoea, pernicious anaemia, hypochronic anaemia
What are examples of malabsorption conditions?
- Coeliac disease
- Pancreatitis
- Crohn’s disease
- Lactase deficiency
What is the sphincter called between the small intestine and the caecum?
Ileocaecal valve
What is the blood supply to the S.I?
SMA
Is the duodenum retroperitoneal or intraperitoneal?
Mostly retroperitoneal
What marks the duodeno-jejunal flexure?
Ligament of Treitz
What are the relations of the duodenum?
R kidney, R suprarenal gland, pancreas
How many parts are there in the duodenum?
4
What is the lymphatic drainage of the duodenum?
Anterior: pancreatoduodenal lymph nodes –> pyloric nodes
Posterior: superior mesenteric lymph nodes
