6.10 - Absorption

Question 1

What is the ileum?

Answer 1

Final section of the small intestine

Question 2

What is the function of the ileum?

Answer 2

Absorb digested food molecules

Question 3

What are adaptations of the ileum for absorption?

Name 3

Answer 3

• The walls are folded into finger-like villi to increase surface area.
• Epithelial cells have microvilli to further increase surface area.
• It has thin walls reduce diffusion distance.
• It has an extensive capillary network and a good blood supply to maintain steep diffusion gradients.
• Muscles in the ileum wall contract to mix content and bring new material into contact with villi.

Question 4

What are amino acids formed from?

In digestion amino acids are the product of hydrolysis of what?

Answer 4

Breakdown of proteins

Question 5

What are monosaccharides formed from?

In digestion produced from hydrolysis of what?

Answer 5

Breakdown of carbohydrates

Question 6

How are amino acids and monosaccharides absorbed?

Answer 6

Co-transport

Question 7

How does co-transport work in the ileum?

Answer 7

1. Sodium ions are actively transported out of ileum epithelial cells.
2. This sets up a sodium ion concentration gradient between the ileum lumen and the epithelial cells.
3. Sodium ions are co-transported with amino acids or monosaccharides from the lumen into the epithelial cells.
4. Amino acids and monosaccharides move by facilitated diffusion from epithelial cells into the blood.

Question 8

What are triglycerides broken down into?

Answer 8

Monoglycerides and fatty acids

Question 9

What do monoglycerides and fatty acids form with bile salts?

Answer 9

Micelles

Question 10

How are triglycerides absorbed?

Answer 10

Micelles release fatty acids and monoglycerides

Question 11

What are chylomicrons?

Answer 11

Triglycerides packaged for transport

Question 12

What are lacteals?

Answer 12

Lymphatic vessels in the villi