12.1

Question 1

What is the function of the oesophagus? (1)

Answer 1

carries food from the mouth to the stomach

Question 2

What is the function of the stomach? (2)

Answer 2

(1) stores & digests food physically (by churning) & chemically
(2) It especially digests proteins, as it has glands that secrete protease enzymes

Question 3

What tissues is the stomach made of? (2)

Answer 3

(1) muscular
(2) glandular = has an inner layer that produces enzymes

Question 4

What does the small intestine consist of? (2)

Answer 4

(1) duodenum
(2) ileum

Question 5

What happens in the duodenum? (2)

Answer 5

(1) digestion continues using enzymes from the pancreas (amylase & lipase)
(2) Secretions from the liver via the gall bladder assist the activity of these enzymes (bile)

Question 6

What type of tissues make up the ileum? (1)

Answer 6

Muscular

Question 7

Does the ileum produce & secrete its own enzymes? (1)

Answer 7

Yes

Question 8

How is the ileum adapted for absorption? (4)

Answer 8

(1) its inner walls are folded into villi = large S.A.
(2) these villi are further folded into microvilli = larger S.A.
(3) has epithelial cells lining the villi = maintain conc. gradient
(4) has a good blood supply = maintain conc. gradient

Question 9

What is the function of the large intestine / colon? (1)

Answer 9

it absorbs water

Question 10

What is the function of the rectum? (1)

Answer 10

it stores faeces

Question 11

What is the function of the anus? (1)

Answer 11

egestion = periodically removing faeces from the body

Question 12

What is the function of the salivary glands? (1)

Answer 12

they secrete enzymes into the mouth (e.g. amylase)

Question 13

What is the function of the pancreas? (2)

Answer 13

(1) it produces a secretion called the pancreatic juice
(2) which contains proteases, lipase, and amylase

Question 14

What is the definition of chemical digestion? (2)

Answer 14

(1) the process in which large, insoluble molecules
(2) are hydrolysed by enzymes
(3) to produce smaller, soluble molecules

Question 15

Give examples of how food is physically digested. (2)

Answer 15

(1) food is broken down into smaller pieces by the teeth (that provides a large S.A. for chemical digestion)
(2) food is churned by the muscles in the stomach wall

Question 16

Why do we need to digest food? (1)

Answer 16

to absorb useful nutrients & minerals

Question 17

The pancreas can be described as an exocrine & an endocrine gland. Explain why. (2)

Answer 17

(1) it releases enzymes via a duct into the duodenum
(2) it releases hormoneslike insulin directly into the blood stream

Question 18

What is meant by egestion? (2)

Answer 18

(1) the expulsion of faeces
(2) from the rectum via the anus