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)

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

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

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

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

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

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

Recap

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.

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

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