Topic 5 Digestive System: Small Intestine

Question 1

• Food goes from stomach to the small intestine through the pyloric sphincter

Answer 1

Path

Question 2

• Duodenum
• Jejunum
• Ileum

Answer 2

Parts of small intestin

Question 3

• continues breakdown of starches and proteins as well as remaining food types (fats and nucleotides)

Answer 3

Duodenum

Question 4

• absorption of nutrients

Answer 4

Jejunum

Question 5

• absorption of nutrients, longest portion and contains Peyer’s patches, which are large aggregates of lymphoid tissue

Answer 5

Ileum

Question 6

• 90% of digestion and absorption occurs in the small intestine, and the structure is connected to the large intestine via the ileocecal valve

Answer 6

Note

Question 7

• Finger-like projections called villi that increase the surface area to allow for greater digestion and absorption
• Each villi has a lacteal, a lymph vessel surrounded by a capillary network that functions for nutrient absorption
• Villi have microvilli allowing for greater surface area
  a. Goblet cells are found here and secrete mucus to lubricate and protect from mechanical or chemical damage
  b. Duodenum has a pH of about 6 mainly due to bicarbonate ions secreted by pancreas. Majority of digestion occurs here while the majority of absorption occurs in jejunum

Answer 7

Structure

Question 8

• Proteolytic enzymes like proteases, disaccharidases, lipases, nucleotidades, phosphatases, and nucleosidases

Answer 8

Enzyme Origin