digestive system

Question 1

how are the enzymes in the digestive system produced

Answer 1

by specialised cells in glands and gut lining

Question 2

structure of digestive system (10)

Answer 2

mouth, oesophagus, stomach, liver, gall bladder, bile duct, pancreas, small intestine, large intestine, anus

Question 3

what happens in the mouth

Answer 3

amylase in the saliva begin to digest starch

Question 4

what is produced in the stomach

Answer 4

it secretes protease enzymes

Question 5

what happens in the liver

Answer 5

secreted bile which neutralises stomach acids and emulsifies fat to tiny droplets

Question 6

what happens through the bile duct

Answer 6

transports bile from liver to work in small intestine

Question 7

what is produced in the pancreas

Answer 7

produces protease, carbohydrase and lipas enzymes and releases them to the small intestine

Question 8

what happens in the small intestine

Answer 8

1) produces protease, carbohydrase and lipase enzymes to complete digestion to glucose, amino acids, fatty acids + glycerol
2) where digested food is absorbed out of the digestive system and into the blood

Question 9

what happens in the large intestine

Answer 9

absorbs excess water

Question 10

name of how is food moved through the gut and explain

Answer 10

peristalsis
1) there’s muscular tissue all the way along the passage that food passes through during digestion
2) this squeezes balls of food (boluses) through the gut or it’ll get clogged up with bits of old food
3) squeezing action = waves of circular muscle contraction and relaxation is peristalsis

Question 11

how are dissolved food and water absorbed in the digestive system

Answer 11

digestion produces soluble substances e.g glucose which is absorbed in the small intestine

Question 12

what is the inside of the small intestine covered with

Answer 12

millions of tiny projections of villi

Question 13

what is the main reason for villis quick absorption

Answer 13

increases surface area so soluble substances are quickly absorbed into the blood by diffusion

Question 14

what is a reason that assists villis quick absorbtion

Answer 14

containing blood vessels
= good blood supply so the soluble substances are taken away in the blood which helps maintain a steep diffusion gradient

Question 15

what are 2 limitations of using visking tubing to model the gut

Answer 15

1) bad blood supply so it cant maintain a diffusion gradient from inside the tubing to the outside
2) visking tubing doesnt have any villi so the surface area is smaller