Mod 10 - Digestion Physiology - Quiz 1

Question 1

What is the function of the following substrates in the stomach?
A: gastric lipase
B: intrinsic factor
C: mucus
D: pepsin
E: HCl

Answer 1

A: digests a small amount of lipid
B: binds to vit B12 and aids its absoption
C: protects stomach lining from digestion
D: digests proteins into smaller peptide chains, activates pepsinogen to pepsin
E: antibacterial, decreases stomach pH to activate pepsinogen to pepsin

Question 2

Which are only protein digesting enzymes secreted from the pancreas?

Answer 2

Trypsin, chymotrypsin, carboxypeptidase

Question 3

Describe the component structure of tunic serosa/adventitia of the digestive tract.

Answer 3

Contains a layer of connective tissue

Question 4

Describe the component structure of tunic mucosa of the digestive tract.

Answer 4

Has lamina propria, muscularis mucosa and epithelia

Question 5

Describe the component structure of tunic submucosa of the digestive tract.

Answer 5

Contains glands, blood vessels, lymphatic vessels in a thick connective tissue layer. Also contains nerves making up the Meissner complex

Question 6

What are the functions of each oral cavity secretions?
A: lingual lipase
B: mucous
C: salivary amylase
D: serous saliva

Answer 6

A: digests a small amount of lipid
B: lubricates food and protects digestive tract from digestion by enzymes
C: digests carbohydrates
D: flushes bacteria from teeth, neutralises bacterial acids, moistens food and mucous membranes

Question 7

Describe the component structure of tunic muscularis of the digestive tract.

Answer 7

Contains a layer of circular smooth muscle and a layer of longitudinal smooth muscle

Question 8

Describe the Cephalic phase

Answer 8

Taste, smell, chewing and swallowing of food

Postganglionic neurons stimulate secretion by parietal and chief cells

Secretion of gastrin by the stomach into the blood

Question 9

Describe the Gastric phase

Answer 9

Distention of the stomach

…stimulates mechanoreceptors. Action potentials travel to the medulla via vagus nerve

Medulla sends action potentials down vagus nerve to stimulate secretions of gastrin and histamine by endocrine cells

Question 10

Describe the Intestinal phase

Answer 10

Chyme goes into duodenum

A pH

Question 11

Describe action and function of cholecystokinin (CCK)

Answer 11

• produced by the duodenum
• stimulates the release of bile from gall bladder and secretion of pancreatic juice from pancreas
• decreases gastric secretions in the stomach

Question 12

Describe the function of secretin

Answer 12

• Stimulates bile secretion from the pancreas into the duodenum
• increase bicarbonate ion content of bile to increae pH and protect duodenum from acidic pH

Question 13

What processes of an amino acid occur to be absorbed into intestinal cells?

Answer 13

Moves out of intestinal cell by diffusion

active symporting into intestinal cells by a similar manner to glucose

Question 14

What processes of glucose occur to be absorbed into intestinal cells?

Answer 14

Symporting with Na+ moving down concentration gradient

Moves out of intestinal cell by facilitated diffusion

Question 15

What processes of lipids occur to be absorbed into intestinal cells?

Answer 15

Micelles attach to plasma membranes of intestinal cells and lipid diffuses into cell

Cholymicrons move out of intestinal cells by exocytosis

Question 16

____ litres of water is absorbed by the digestive system each day. ___% is absorbed by small intestine and ___% is absorbed by large intetsine.

Answer 16

9L

92%

6-7%

Question 17

How are ions (Na+, K+, Ca2 etc) transported into intestinal cells?

How are Cl- ions transported in the duodenum and jejunum, then in the ilium?

Answer 17

Active transport

Duodenum and jejunum = passive

Ilium = active

Question 18

How are fat soluble vitamins absorbed?

Answer 18

With lipids in micelles