Introduction

Question 1

What are blood vessels?

Answer 1

Tubes that carry blood around your body.

Question 2

Your _____ and ________ ______ make up your blood system.

Answer 2

Heart and Blood Vessels

Question 3

What is your blood system often called?

Answer 3

The circulatory system

Question 4

What does your blood system transport?

Answer 4

• Oxygen from your lungs to your cells

- Food from your gut to your cells

Question 5

What waste chemicals does your blood system remove?

Answer 5

• Carbon dioxide from your cells to your lungs

- Waste chemicals from your liver to your kidneys

Question 6

What chemicals does your blood system transport?

Answer 6

Hormones,antibodies and blood proteins to all the cells of your body.

Question 7

True or false

Many small animals do not need a blood system

Answer 7

True

Question 8

How do microscopic organisms get oxygen?

Answer 8

They can get oxygen by diffusion

Question 9

Why is it easy for microscopic organism to get oxygens?

Answer 9

They have a large surface area compared to their volume, it is easy for things to diffuse in and out.

Question 10

Why do larger vertebrates like flatworms not need blood vessels?

Answer 10

Their bodies are so flat that is not far for gases and liquids to diffuse in and out.

Question 11

Why do we need a transport system?

Answer 11

We can not just rely upon diffusion. Our bodies are too large for materials to simply diffuse in and out. It would take a molecule of oxygen days to diffuse from the outside to the centre of your brain! We have a system of tubes and a pump to carry substances around our body quickly.

Question 12

What is at the centre of your blood system?

Answer 12

Your heart

Question 13

What is the heart’s job?

Answer 13

Pump blood around your body

Question 14

What are the 2 types of blood vessels?

Answer 14

Arteries and veins

Question 15

What are arteries?

Answer 15

Carry blood away from the heart

Question 16

What are veins?

Answer 16

Carry blood back to the heart

Question 17

When arteries get to an organ in your body arteries branch many times. The smallest branches are called___________. The they join up to form ____.

Answer 17

Capillaries

Veins

Question 18

Wat happens in the capillaries?

Answer 18

Chemicals likes oxygen, food and carbon dioxide pass into and out of the blood.

Question 19

What is the circulatory compared to?

Answer 19

It is like a one way street, blood can only go in one direction .

Question 20

What happens at capillaries?

Answer 20

The arteries branch many times until the smallest branches form capillaries. These are very narrow and taper as they reach the body cells. Here a red blood cell can only just squeeze through. Blood flows through capillaries very slowly, so this gives time for exchange of materials to take place.

Question 21

Capillary ____ are only one cell thick. _____ and ____ can easily pass out of the capillary to the cells. Carbon dioxide and other waste chemicals can easily pass from the cells into the capillary.

Answer 21

Walls
Oxygen
Food

Question 22

There over _____ capillaries in your body.

Answer 22

80 000km