Biological Digestion

Question 1

What does the small intestine absorb?

Answer 1

nutrients from food

Question 2

What does the large intestine absorb?

Answer 2

water from food

Question 3

What are the names of the layers of the intestines?

Answer 3

mucosa
muscle layers
serosa

Question 4

What is the mucosa?

Answer 4

the innermost layer of the intestinal wall

Question 5

What does the mucosa consist of?

Answer 5

mucosal ducts and glands that generate mucous that covers the internal surface of the intestines

villi that increase surface area in contact with the contents of the intestine

lacteals which are lymphatic capillaries in the villi
lacteals absorb fat and fat-soluble vitamins and transport them into the bloodstream

Question 6

What does osmosis mean?

Answer 6

nutrient molecules travelling across a semi-permeable membrane

Question 7

What does diffusion mean?

Answer 7

nutrient molecules travelling from high concentration to low concentration

Question 8

What does active transport mean?

Answer 8

nutrient molecules travelling from low concentration from high concentration

Question 9

What are the two muscle layers surrounding the mucosa?

Answer 9

first is a circular layer of muscle that forms a ring round the intestine

second is a layer of muscle arranged longitudinally along the length of the intestine

Question 10

What do the contractions of the muscles surrounding the mucosa cause?

Answer 10

food to move through the intestine

Question 11

What is the serosa?

Answer 11

a smooth membrane that surround the intestines

Question 12

What does the serosa secrete?

Answer 12

a substance called serous

Question 13

What does serous do?

Answer 13

helps reduce friction from the muscle movement