Digestive Secretions

Question 1

What is a salivary gland?

Answer 1

Three pairs of glands in the mouth that secrete saliva, which dissolves food so it can be tasted.

Question 2

What is the role of salivary glands in producing saliva containing enzymes?

Answer 2

They secret saliva which contains mucus that lubricates the mouth and holds food in a lump for swallowing. It also contains the enzyme salivary amylase, which begins the chemical digestion of starch.

Question 3

What is the role of the liver in producing bile to aid in fat digestion?

Answer 3

Produces bile, which is stored and concentrated in the gall bladder. Bile emulsifies lipids in the small intestine aiding in fat digestion.

Question 4

What is the role of the gall bladder in storing and releasing bile into the small intestine?

Answer 4

The gall bladder stores bile and releases it into the small intestine, where the bile emulsifies lipids.

Question 5

What is the role of the pancreas in producing digestive enzymes?

Answer 5

The pancreas produces pancreatic juice containing enzymes for digesting proteins, lipids, and nucleic acid.

It contains enzymes such as pancreatic amylase, pancreatic protease, pancreatic lipases, and ribonuclease and deoxyribonuclease

Question 6

What is the role of bile in breaking down fats?

Answer 6

Bile contains no digestive enzymes but has bile salts important for the digestion of fats

Bile salts break the fat into tiny droplets; a form of MD that increases the surface area on which lipases can act to chemically break down the fat.

Question 7

What do the enzymes in the pancreas break down

Answer 7

1. Pancreatic amylase: breaks down starch
2. Pancreatic protease: breaks down proteins into small chains of amino acids
3. RNA/DNA - digest RNA/DNA
4. Pancreatic lipases - break down fats into fatty acids & glycerol

Question 8

What is the role of the mucosa?

Answer 8

Specialised for the secretion of gastric juice by gastric glands located in narrow, tub-like structures called gastric pits

Question 9

What is gastric juice?

Answer 9

A digestive juice containing hydrochloric acid, mucus and digestive enzymes - secreted by a different type of cell in the gastric pits.

Question 10

What is the role of gastric juice?

Answer 10

Gastric juice is responsible for chemical digestion in the stomach, which is mainly the start of protein digestion.