2.3 - The Digestive System

Question 1

What is the Role of Digestion?

Answer 1

To break food down into tiny pieces so we can absorb it into our cells.

Question 2

Where does Digestion Start?

Answer 2

The Mouth

Question 3

What are the 3 Functions of the Mouth to Aid Digestion?

Answer 3

• Breaks food down physically by chewing.
• Salivary glands release saliva to make the mixture more liquid.
• Salivary glands contain salivary amylase which help break down carbohydrates.

Question 4

What happens when you Swallow Food?

Answer 4

• It passes through your gullet (oesophagus).
• Then passes through to your stomach.

Question 5

What are the 3 Functions of the Stomach to Aid Digestion?

Answer 5

• Contracts muscular walls to push food around and mix it.
• Produces pepsin which is a protease enzyme which breaks down proteins.
• Produces hydrochloric acid which kills bacteria & provides the right environment for pepsin to work.

Question 6

Roughly how long does Food stay in the Stomach?

Answer 6

An Hour

Question 7

Where does Food go whilst exiting the Stomach?

Answer 7

It is squeezed out into the Small Intestine.

Question 8

What is the Function of the Small Intestine?

Answer 8

• Where the digested food is absorbed into the bloodstream.
• Produces digestive enzymes to aid digestion.

Question 9

Which Organ makes most of the Digestive Enzymes?

Answer 9

The Pancreas

Question 10

How are Digestive Enzymes in the Pancreas taken to the Small Intestine?

Answer 10

Pushes them into the small intestine in the form of pancreatic juices.

Question 11

What is the Function of the Gall Bladder?

Answer 11

• To Release Bile.
• To Emulsify Fats into tiny droplets, helps by giving the Fat a much bigger Surface Area for the Digestive Enzymes to work on.

Question 12

What are the Functions of Bile?

Answer 12

• Neutralising the Stomach Acid.
• Making the pH more Optimal for the Digestive Enzymes to Function.

Question 13

Where is Bile made?

Answer 13

In the Liver

Question 14

What happens once Food has been Digested?

Answer 14

It is absorbed across the lining of the intestine straight into the bloodstream.

Question 15

How is the Lining of the Small Intestine adapted to its Function? [3]

Answer 15

• Villi which Increase Surface Area for quicker absorption of Food into the Bloodstream.
• Only a single layer of Surface Cells so the Nutrients only have to Diffuse a Short Distance.
• Very good Blood Supply which maintains the Concentration Gradient.

Question 16

Where does Food go whilst exiting the Small Intestine?

Answer 16

The Large Intestine

Question 17

What is the Function of the Large Intestine?

Answer 17

• Absorbs Excess Water.
• Leaves behind Faeces which are Stored in the Rectum until Removed.

Question 18

What is the Order of Digestion?

Answer 18

Mouth –> Gullet/Oesophagus –> Stomach –> Small Intestine –> Large Intestine –> Rectum