Nutrition - Alimentary Canal

Question 1

Mouth (3)

Answer 1

food is chewed up forming a bolus coated in saliva. The saliva lubricates the food and contains digestive enzymes that start to chemically break down the food.

Question 2

Oesophagus

Answer 2

food passes down this tube through peristalsis.

Question 3

Peristalsis

Answer 3

waves of muscle contraction.

Question 4

Stomach (2)

Answer 4

contains digestive enzymes to break down the food and rsecretes hydrochloric acid to kill pathogens.

Question 5

Small intestine (3)

Answer 5

most food is broken down by digestive enzymes and absorbed into the blood vessels in the small intestine. Walls are lined up with villi.

Question 6

Large intestine

Answer 6

water is reabsorbed into the blood vessels.

Question 7

Anus

Answer 7

Undigested food leaves the body as Faeces

Question 8

Pancreas

Answer 8

releases enzymes in the small intestine

Question 9

Liver

Answer 9

produces bile

Question 10

Bile (2)

Answer 10

1. Bile is alkali so it neutralizes the acidity from the stomach, also highers the pH of the food so that the enzymes can work quicker since it will be in their optimum pH
2. Bile also emulsifies fat

Question 11

emulsification

Answer 11

breaking of large lipid droplets to smaller ones so that the surface area increases, therefore the enzymes’ rate for breaking it down will also increase.

Question 12

villi (3)

Answer 12

1. Thin membranes
2. large surface area
3. Good blood supply

Question 13

Bile (2)

Answer 13

1. Bile is alkali so it can neutralize the acidity from the stomach. It gives a higher pH to the food so the enzymes in the small intestine work at their optimum pH.
2. Bile also emulsifies fat

Question 14

Emulsification

Answer 14

the breaking of large lipid droplets to smaller ones so that it can increase their surface area, there fore increasing rate of enzymes breaking it down.

Question 15

Villi (3)

Answer 15

1. Thin walls
2. Good blood supply
3. Surface area