Digestive System

Question 1

why type of digestion occurs in the mouth

Answer 1

amylase breaks down starch

Question 2

what type of digestion occurs in the stomach, any absorption?

Answer 2

very little absorption - caffeine, alcohol, meds

pepsin breaks down proteins

Question 3

what is responsible for the acidity of the stomach

Answer 3

parietal cells secrete gastric acid to keep ph 1.5-3.5 for optimal digestive enzyme functioning

Question 4

how is pepsin an example of a zymogen

Answer 4

chief cells releases the precursor pepsinogen which is cleaved in acidic conditions to form pepsin

Question 5

what digestion happens in the small intestine

Answer 5

brush border enzymes called disaaccharidases
peptidases break down peptides
pancreas and liver contributions as well

Question 6

what does the pancreas secrete for digestion

Answer 6

alkaline fluid with several digestive enzymes

Question 7

what does the liver secrete for digestion

Answer 7

bile which is stored in the gall bladder is released in the small intestine to emulsify fats and convert them to micelles

Question 8

how can acidic chyme from the stomach be neutralized in the small intestine

Answer 8

pancreas alkaline fluid
bile is alkaline
duodenum secretes a bicarbonate buffer

Question 9

where does absorption occur in the small intestine

Answer 9

jejunum and ileum

villa increase the surface area and are lined with enterocytes which also have microvilla

Question 10

what type of digestion occurs in the large intestine , absorption?

Answer 10

absorbs water from the food
gut bacteria for vit K and B
no chemical digestion just absorption of remaining nutrients

Question 11

what does the hormone somatostatin do

Answer 11

body slowing
inhibits the hormones involved in digestion like gastrin CCK and secretin 
decreases stomach emptying 
inhibits release of glucagon and insulin
inhibits release of growth hormone

Question 12

how are carbs/proteins absorbed vs lipids

Answer 12

secondary active transport into epithelial cells which then enter circulatory system via facilitated diffusion
capillaries drain into the hepatic portal vein which go to the liver before entering systemic circulation

Question 13

how are lipids absorbed

Answer 13

formed into micelles which are absorbed into epithelial cells
fat droplets called chylomicrons are formed which move to lacteals which pass through the lymphatic system which drains into the venous circulation

Question 14

describe the path a piece of meat would take through your body

Answer 14

stomach - pepsin
SI - peptidases break down into single amino acids which enter epithelial cells of the small intestine lining through secondary active transport
enter blood stream and go to the liver

Question 15

describe the path a potato would take through your body

Answer 15

mouth - amylase breaks down into disaccharide
SI - broken down by many enzymes, disaccharidases produce monosaccharides which enter epithelial cells
then goes to blood stream then the liver
undigested starch goes to large intestine

Question 16

describe the path fats would take in your body

Answer 16

mouth - lingual lipase
SI - pancreatic lipase breaks triglycerides down into free fatty acids
bile salts make them into micelles which can enter the epithelial cells on their own
packaged into chylomicrons into lacteals which drain into lymphatic system then the venous circulation

Question 17

vitamin A

Answer 17

vision

Question 18

vitamin d

Answer 18

calcium and phosphate absorption from gut

Question 19

vitamin e

Answer 19

antioxidant

Question 20

vitamin K

Answer 20

coagulation

Question 21

vitamin c

Answer 21

cofactor for collagen synthesis

Question 22

vitamin b

Answer 22

coenzymes or cofactor