6.10 absorption of products of digestion
- Created by: germaineconroy
- Created on: 08-02-18 09:18
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- 6.10 Absorption of products of digestion
- The structure of the ileum
- Adapt. to function of absorption
- Wall folded & finger-like projections (villus)
- ^SA -> accelerate rate of absorption
- Villus situated interface BTWN lumen of intest + blood/ othr tiss inside body
- Part specialised exchange surface adap for absorp
- ^SA for diffusion
- Thin walled, reducing diffusion path
- cont. muscle so able to move -> help maintain diff gradient bc movement mix contents ileum
- Well sup w/ blood vessels so blood carry away abs mol - maint diff gradient
- Epithelial cells lining villus possess microvillus - further ^ SA
- Part specialised exchange surface adap for absorp
- Thin walls, lined w/ epith cells on opp side which rich with network blood capil.
- Absorption of AA and monosaccharides
- digest prot produce AA
- digest monosacc -> glucose, fructose & galactose
- Diffusion & co-transport
- Absorption Triglycerides
- Once formed during digest. Monogly & FA remain associated w/ bile salts that initially emulsified lipid droplets
- Struc formed called micelles - tiny - 4-7nm.
- Thro move mat w/n lumen, micelles in contact w/ epithelial cells, lining villi of lumen
- Micelles breakdown, releasing monoglyc & FA.
- As non-polar mol - easy diffuse across CSM into epithelial cell
- Once indise epith, monoglyc + FA transport to endoplasmic reticulum where recombined to form triglycerides.
- Starting in ER & ending at Golgi A, triglyc associate w/ cholesterol & lipoproteins to form struc: chylomicrons - adapted to transport lipids
- Chlyomicrons move out of epithelial cells by exocytosis.
- Enter lymphatic capillaries called lacteals in centre of each villus
- Chlyomicrons move out of epithelial cells by exocytosis.
- Starting in ER & ending at Golgi A, triglyc associate w/ cholesterol & lipoproteins to form struc: chylomicrons - adapted to transport lipids
- Once indise epith, monoglyc + FA transport to endoplasmic reticulum where recombined to form triglycerides.
- As non-polar mol - easy diffuse across CSM into epithelial cell
- The structure of the ileum
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