Organisation: The Digestive System

Question 1

What is the main function of the digestive system?

Answer 1

To break down food enable the absorption of the nutrients obtained from digestion

Question 2

What is the role of the pancreas in the digestive system?

Answer 2

Produces digestive juices containing all 3 digestive enzymes

Question 3

What is the role of the salivary gland in the digestive system?

Answer 3

Produces digestive juices containing amylase

Question 4

What is the role of the stomach in the digestive system?

Answer 4

1. Has thick muscular walls which contract and pummel the food
2. Produces pepsin (a protease enzyme)
3. Produces hydrochloric acid

Question 5

What is the role of hydrochloric acid in the stomach?

Answer 5

• kills bacteria
• provides the optimum pH for the protease enzyme to function

Question 6

What is the role of the small intestine in the digestive system?

Answer 6

The site where soluble food molecules are absorbed into the bloodstream

Question 7

How is the small intestine adapted for the absorption of digestive food into the bloodstream?

Answer 7

• has villi
• single cell thick
• good blood supply

Question 8

How do villi increase the rate of absorption of digested food into the bloodstream?

Answer 8

They increase the surface area of the small intestine.

Question 9

How does surface cells of small intestine being one cell thick increase the rate of absorption of digested food into the bloodstream?

Answer 9

Provides a short diffusion pathway

Question 10

How does a good blood supply to the small intestine increase the rate of absorption of digested food into the bloodstream?

Answer 10

Maintains the concentration gradient

Question 11

What is the role of the liver in the digestive system?

Answer 11

Produces bile

Question 12

What is the role of the gallbladder in the digestive system?

Answer 12

Stores bile

Question 13

What are the two function of bile in the digestion of food?

Answer 13

• emulsifies fats which increases their surface area
• neutralises acid from stomach allowing lipase enzyme to work more efficiently

Question 14

What is the role of the large intestine in the digestive system?

Answer 14

Absorbs excess water from undigested food producing faeces

Question 15

What is the role of enzymes in the digestive system?

Answer 15

Biological catalysts that speed up the rate of biological reactions (in this case the breakdown of food) without being used up themselves.