Physiology of the SI and the Exocrine Pancreas

Question 1

What is the small intestine a major site of?

Answer 1

Absorption and digestion

Question 2

3 parts of the SI?

Answer 2

Duodenum
Jejunum
Ileum

Question 3

What does SI receive from stomach? via what sphinter?

Answer 3

Chyme via pyloric sphincter

Question 4

What does SI receive from pancreas?

Answer 4

Pancreatic juice

Question 5

What does SI receive from GB and Liver? Via what sphincter?

Answer 5

Bile

Via sphincter of Oddi

Question 6

What does SI secrete?

Answer 6

Intestinal juice

Question 7

What does Motility in SI cause?

Answer 7

• Segmentation
• Peristalsis
• Migrating motor complex

Question 8

What is segmentation?

Answer 8

Mixing of chyme with digestive juice

Question 9

What is peristalsis?

Answer 9

Slow repulsion of chyme aborally

Question 10

What is removal of undigested residues to large intestine via ileo-caecal valve?

Answer 10

Migrating motor complex

Question 11

Adaptions of SI for absorption?

Answer 11

SA increased by circular folds, villi, microvilli

Question 12

Segmentation summary?

Answer 12

• Chopping moves chyme back and forth after meals
• Alternating contraction & relaxation of segments of circular muscle
• Strength of segmentation is enhanced by parasympathetic activity

Question 13

What is MMC?

Answer 13

Migrating Motor complex

Question 14

What does MMC do?

Answer 14

Occurs between meals
-Strong peristaltic contraction slowly passing length of intestine, clears small intestine of debris mucous and sloughed epithelial cells between meals

Question 15

What is peristalsis inhibited by?

Answer 15

Eating and vagal activity.

Triggered by motilin