B3 Digestive System

Question 1

Tissue

Answer 1

A group of cells with similar structures and functions working together

Question 2

Organs

Answer 2

Collections of tissues performing specific functions

Question 3

Organ system

Answer 3

Group of organs working together to form organisms

Question 4

Muscular tissue: function

Answer 4

Able to contract to bring about movement

Question 5

Glandular tissue: function

Answer 5

Able to produce and release substances such as enzymes and hormones

Question 6

Epithelial tissue: function

Answer 6

Covers the outside of the body and internal organs - protective layer

Question 7

What is digestion?

Answer 7

Large food molecules are broken down into smaller ones which can be absorbed into the bloodstream
- Starch -> Glucose
- Proteins -> Amino Acids
- Lipids -> Fatty Acids and Glycerol

Question 8

What are the organs in the digestive system? (in order)

Answer 8

• Mouth
• Oesophagus
• Stomach
• Small Intestine
• Large Intestine
• Anus
  Food does not go through here but is still part of the digestive system
• Liver
• Pancreas

Question 9

What happens in the mouth?

Answer 9

Food is chewed by teeth and mixed with saliva

Question 10

How is the mouth adapted for absorption?

Answer 10

Food is broken down into smaller pieces by teeth and enzymes in saliva start to break down starch

Question 11

What happens in the oesophagus?

Answer 11

Food is pushed down into the stomach

Question 12

How is the oesophagus adapted for absorption?

Answer 12

Stretchy and muscular -> pushes food down even when you’re upside down - Peristalsis

Question 13

What happens in the stomach?

Answer 13

Food is churned with acids and enzymes

Question 14

How is the stomach adapted for absorption

Answer 14

• Acids kill bacteria -> Walls protected by mucus
• Enzymes break food into smaller pieces

Question 15

What happens in the small intestines?

Answer 15

• Enzymes finish breaking down most food
• Food is absorbed through the walls into the bloodstream

Question 16

How are the small intestines adapted for absorption?

Answer 16

Villi on the wall gives it a large surface area -> faster rate of diffusion

Question 17

What happens in the large intestines?

Answer 17

Water is absorbed from undigested food

Question 18

How are the large intestines adapted for absorption?

Answer 18

Contains millions of bacteria which break down undigested food

Question 19

What happens in the anus?

Answer 19

Waste gets excreted

Question 20

How is the anus adapted for absorption?

Answer 20

You can control the muscles which open and close it

Question 21

What happens in the liver?

Answer 21

Bile is produced which:
- Neutralises food exiting the stomach (acidic)
- Break down fat into smaller pieces to increase surface area for lipase to work

Question 22

Carbohydrates

Answer 22

Contains carbon, hydrogen, and oxygen
- Simple sugars contain one sugar unit like glucose or two sugar units like sucrose
- Complex carbohydrates like starch or cellulose are long chains of simple sugars bonded together
- The glucose is used for aerobic respiration

Question 23

Lipids