Absorption of the Products of Digestion

Question 1

What is the structure of the ileum?

Answer 1

-Folded inner walls with villi
-Thin walls linked with epithelial cells and a rich network of blood capillaries

Question 2

How is the ileum adapted for the function of absorption?

Answer 2

-Large SA:V for diffusion
-Thin walled
-Contain muscle allowing them to move (Maintaining concentration gradients)
-Well supplied with blood vessels
-Microvilli

Question 3

How are monosaccharides and amino acids absorbed?

Answer 3

-Diffusion and co-transport

Question 4

How are triglycerides absorbed?

Answer 4

-Micelle formation (Monoglycerides and fatty acids in combination with bile salts)
-Contact with epithelial cells, and due to non-polar nature, easily diffuse through cell-surface membrane
-Transported to endoplasmic reticulum where they are recombined to form triglycerides
-Triglycerides associate with cholesterol and lipoproteins to form structures called chylomicrons
-Chylomicrons move out of epithelial cels by exocytosis and enter lymphatic capillaries called lacteals found in the middle of each villus