Block 3 Lecture 2 digestion of carbs

Question 1

what are carbohhydrates broken down into for absorption?

Answer 1

monosaccharides

Question 2

what are fats broken down into?

Answer 2

fatty acids and glycerol

Question 3

what is in salivary secretions?

Answer 3

water, ions, salivary amylase and lysozymes

Question 4

what do mucous cells in the stomach secrete and what is the function of their secretion?

Answer 4

mucous to protect the epithelium from acid secretions

Question 5

what do parietal cells secrete and what is the function of their secretion?

Answer 5

gastric acid and intrinsic factor, HCL helps with food digestion and intrinsic factor is needed for B12 absoption

Question 6

what do chief cells secrete and what is the function of their secretion?

Answer 6

pepsinogen the precurser of pepsin which is a proteolytic enzyme

Question 7

what do enterendocrine cells in the stomach secrete and what is the function of their secretion?

Answer 7

G cells secrete gastrin which is a hormone

Question 8

what are the different phases of gastric secretion?

Answer 8

cephalic, gastric, intestinal

Question 9

what is cephalic secretion stimulated by?

Answer 9

stimulated by sight, smell, taste by the vagus nerve

Question 10

when does gastric secretion occur?

Answer 10

when food is in the stomach

Question 11

what stimulates gastric secretion from parietal cells? (3)

Answer 11

histamine, gastrin and acetylecholine

Question 12

how does histamine stimulate parietal cells?

Answer 12

histamine is released by enterochromaffin like cells, it binds to the H2 receptors on parietal cells and activates adenyl cyclase which generates CAMP which activates protein kinases which activates the hydrogen potassium pump

Question 13

what two ways does gastrin stimulate HCL release?

Answer 13

1. gastrin is released from G cells which binds to CCK2 receptors inducing a release of cystolic calcium ions, which activates protein kinases which activates the hydrogen potassium pump
2. stimulates ECL cells to secrete histamine

Question 14

how does acetlycholine induce HCL release?

Answer 14

binds to M3 receptors to increase intracellular callcium, which activates protein kinases which activates the hydrogen potassium pump

Question 15

what does secretin do?

Answer 15

secreted by the duodemun in response to acid, it inhibits gastric acid secretion

Question 16

where is somatostatin released and what does it do?

Answer 16

D cells in the stomach and duodenum in response to acid, it inhibits gastric acid secretion

Question 17

where is CCK secreted and what does it do?

Answer 17

duodenum, inhibits gastric secretion, stimulates the secretion of pancreatic bicarbonate and bile

Question 18

an example of H2 antagonist?

Answer 18

omeprazole

Question 19

what bacteria is responsible for gastric ulcers?

Answer 19

helicobacter pylori

Question 20

where does venous drainage from the small intestine go?

Answer 20

hepatic portal vein to the liver

Question 21

what effect does gastric acid have on proteins?

Answer 21

protein denaturation

Question 22

what breaks down proteins?

Answer 22

pepsin

Question 23

what does lipase digest?

Answer 23

triglycerol

Question 24

where does absorption begin?

Answer 24

jejunum

Question 25

why are proteases secreted as inactive precursers?

Answer 25

stops the digestive tract digesting its self

Question 26

what is the product and enzyme involved in maltose breakdown?

Answer 26

2 molecules of glucose and maltase

Question 27

what is broken down to form glucose and galactase? and what is the enzyme?

Answer 27

lactose and lactase

Question 28

what is sucrose broken down into and what is the enzyme involved?

Answer 28

fructrose and glucose and sucrase

Question 29

how is glucose and galactase absorbed?

Answer 29

active transport using sodium co transport.

Question 30

where are non digestible polysaccharidebroken down and what is this process?

Answer 30

fermentation in the colon

Question 31

benefits of non starch polysaccharide?

Answer 31

absorb bile acids and cholesterol bacterial fermentation absorb potential carcinogens

Question 32

what can be used to measure glucose fermentation?

Answer 32

hydrogen breath test

Question 33

where does sodium absorption take place?

Answer 33

colon