Digestive System- Small Intestine

Question 1

absorption

Answer 1

90% of it occurs in the small intestine

Question 2

duodenum

Answer 2

closest to the stomach

25 cm long

receives chyme from stomach and digestive secretions from the pancreas and liver

neutralizes acids before the can damage the lining of the small intestine

Question 3

jejunum

Answer 3

middle section

2.5 meters long

most chemical absorption occurs on the jejunum

has few place circulates that help move things along

contain small villi that also helps stuff move along

Question 4

ileum

Answer 4

final segment

3.5 meters long

ends at the ileocecal valve

Question 5

ileocecal valve

Answer 5

a sphincter that controls flow of material from the ileum to the large intestine

Question 6

intestinal secretion

Answer 6

watery intestinal juice

1.8 liters of the juice enters the intestinal lumen

moistens chyme

assists in buffering acids

keeps digestive enzymes and products of digestion in solution

Question 7

intestinal movements

Answer 7

1. chyme arrives in the duodenum
2. weak peristaltic contractions m move it slowly to jejunum

myenteric reflexes

parasympthathetic stimulation accelerates local peristalsis and segmentation (speed up and separate it)