| Structure of ileum | - Villi
- Thin walls
- Lined with epithelial cells
- Has rich network of blood capillaries |
| Villi | - Between the lumen (cavity) of intestines |
| Adaptations for absorption | - Microvilli, LSA for diffusion
- Thin walls, shorter diffusion path
- Muscles, able to move
- Many blood vessels, carry absorbed molecules, maintains diffusion gradient |
| Digestion and ileum | - Products of digestion are absorbed by ileum epithelium into the bloodstream |
| Absorption of lipids (1) | - Lipase hydrolyses trig. - fatty acids + glycerol
- Most digested into monoglycerides + 2 F.As |
| Absorption of lipids (2) | - Bile salts emulsify the lipids into small droplets, micelle
- Can diffuse into epithelial cells |
| Absorption of lipids (3) | - Trig. then reform and are coated with phospholipids, proteins, cholesterol + chylomicrons |
| Absorption of lipids (4) | - Then released by exocytosis
- Then enter the lacteals of the lymphatic system |
| Absorption of amino acids | - Absorbed same way as glucose |
