1. The Circulatory System
Learning Objective:
To determine the best method of taking your pulse (C)
To describe how blood vessels are adapted to their function (B/A)

2. The Circulatory System
The circulatory system is made up of:
Blood
Arteries
Veins
Capillaries
The Heart

3. Blood Vessels There are 3 types of blood vessel: Arteries Veins
Describe what blood vessels are
Blood Vessels
There are 3 types of blood vessel:
Arteries
Veins
Capillaries

4. Blood Vessels Arteries carry blood Away from the heart
Veins carry blood towards the heart
Capillaries have thin walls to allow oxygen to pass into nearby cells and tissues

5. Artery (Arteries) carry blood away from the heart
Describe what blood vessels are
Artery (Arteries)
carry blood away from the heart
blood is under high pressure generated by the heart
thick outer walls and small lumen
thick layers of muscle and elastic fibres

6. Veins carry blood back to the heart blood is under low pressure
Describe what blood vessels are
Veins
carry blood back to the heart
blood is under low pressure
have thin walls and larger lumen
have thin layers of muscle and elastic fibres
have one-way valves

7. Capillary (Capillaries)
Describe what blood vessels are
Capillary (Capillaries)
Tiny, thin-walled vessels
Carry blood close to all the body's cells in its tissues and organs.
Only one cell thick and has a very small lumen.
Where gas exchange takes place. Oxygen passes through the capillary wall and into the tissues, carbon dioxide passes from the tissues into the blood

8. Recap

9. Blood Vessels Summary Blood vessel Function Adaptations Artery
Describe what blood vessels are
Blood Vessels Summary
Blood vessel
Function
Adaptations
Artery
carry blood away from heart at high pressure
Thick, elastic, muscular walls to withstand pressure and to exert
force (pulse)
Capillary
allow exchange of materials between blood and tissues
Thin permeable walls
Vein
return low pressure blood to
heart
Large diameter to offer least flow resistance. Valves to prevent back flow.

10. Direction of Blood Flow Blood deoxygenated or oxygenated
TASK: Draw an artery, a vein and a capillary and write down the functions and adaptations.
Artery
Vein
Capillary
Diagram
Direction of Blood Flow
Thickness of Wall
Blood deoxygenated or oxygenated
Function
Adaptation

11. Have a go... Draw lines to match the words to their explanations.
These tubes take blood away from the heart.
The transport system of the body.
These tubes carry blood back to the heart.
This pumps blood to the lungs.
The muscle that pumps blood around the body.
The tiny tubes that connect arteries to veins.
This pumps blood around the body.
blood
heart
arteries
veins
left side of heart
right side of heart
capillaries