GI 9 - The Intestines Flashcards
Name the cells in the intestines which secrete antibacterial enzymes ie Lyzozymes + Defensins:
Paneth cells
Approx. how many microvilli are present on each enterocyte?
~ 3000 per cell
What is the approx. total surface area of the GI tract? How much of this is the small intestine?
~ 30 m^2
Small intestines = ~ 20 m^2
How does the small intestine have such massive surface area?
- Folds of Kerckring
- Villi + Crypts of Lieberkuhn
- Microvilli
Where are plicae circulares found?
Small intestine
What type of epithelial cells are found in the intestines?
Simple columnar epithelia
Name the 2 types of starch that we can digest, the enzymes required for digestion, and the products of digestion:
Amylose -> Glucose + Maltose via Amylase
Amylopectin -> alpha-dextrins via Isomaltase
Which monosaccharides are transported by SGLT1 into the enterocyte from the GI lumen?
Glucose
Galactose
Which monosaccharides are transported by GLUT5 into the enterocyte from the GI lumen?
Fructose
How do monosaccharides move across the basolateral membrane of the enterocyte?
GLUT2
Which transporters are present on the apical membrane of the enterocyte for carbohydrate absorption?
SGLT1
GLUT5
Which enzymes to break down carbohydrates are present on the brush-border?
- Maltase
- Isomaltase
- Amylase
- Lactase
- Sucrase
Which enzymes to break down proteins are present on the brush-border?
- Trypsin
- Chemotrypsin
- Elastase
- Carboxypeptidase A + B
Which transporters can move amino acids and peptides into the enterocyte, from the GI lumen?
Na+-AA symporter
PEPT1
What causes micelles to fall apart, allowing the absorption of fats into the enterocytes?
Acidic brush-border (formed by Na+/H+ exchanger)