The Circulatory System

Circulatory System Learning Objectives: By the end of the lesson you should: Be able to summarise the function of the circulatory system. Be able to summarise the function of the circulatory system. Be able to name at least 6 different parts of the heart. Be able to name at least 6 different parts of the heart. Be able to explain how blood is pumped around the body. Be able to explain how blood is pumped around the body. Homework Using page 39 in your ‘Sport Examined’ books explain how we transport oxygen to our muscles.

Your blood works non-stop, 24 hours day. Your blood works non-stop, 24 hours day. It carries carbon dioxide and other waste away. It carries carbon dioxide and other waste away. Blood is pumped round the body by the ‘HEART’. Blood is pumped round the body by the ‘HEART’. It flows along tubes called ‘BLOOD VESSELS’. It flows along tubes called ‘BLOOD VESSELS’. The blood, heart and blood vessels together make up your ‘CIRCULATORY SYSTEM’. The blood, heart and blood vessels together make up your ‘CIRCULATORY SYSTEM’.

How Blood is carried around the body Every time your heart beats it pumps blood at high pressure around your body in tubes in the following order: Every time your heart beats it pumps blood at high pressure around your body in tubes in the following order: Arteries (Thick and elastic) Arteries (Thick and elastic) Arterioles Arterioles Cappillaries (1 cell thick so that blood transfusion can take place) Cappillaries (1 cell thick so that blood transfusion can take place) Venules (deoxygenated blood) Venules (deoxygenated blood) Veins Veins

The valves in veins Blood in veins travels very slowly as it has lower pressure. Blood in veins travels very slowly as it has lower pressure. They have ‘one way’ valves. They have ‘one way’ valves. Most large veins are in your arms and legs. Most large veins are in your arms and legs. When the muscles contract, they squirt the blood towards your heart. When the muscles contract, they squirt the blood towards your heart.

REMEMBER Arteries always carry oxygenated (with O2) blood away from the heart. AND Veins always carry deoxygenated (without O2) blood to the heart.

What does the heart do? The heart is a pump that keeps blood circulating throughout the body. The heart is a pump that keeps blood circulating throughout the body. The Arteries carry oxygenated blood Away from the heart. The Arteries carry oxygenated blood Away from the heart. Veins carry deoxygenated blood into the heart. Veins carry deoxygenated blood into the heart.

The heart is divided into 2 parts. Each part is a pump, so the heart is a double pump. right side The right side pumps deoxygenated blood to the lungs to pick up oxygen. left side The left side pumps oxygenated blood to the rest of the body for use. From the lungs From the body To the lungs To the body How the Heart Pumps Blood

(A) (V) Lungs Heart Body How Blood is Pumped around the Body Blood flows around the body in a ‘figure of eight’ circuit, passing through the heart twice on each circuit. Blood travels away from the heart through arteries (A). Blood returns to the heart through veins (V). There are 2 separate ‘loops’ to the circuit: The top loop – carries blood from the heart to the lungs and back. The bottom loop – carries blood from the heart to all over the body and back. (A) (V)

The Cardiac Cycle - How the Heart Beats Every time the heart beats it goes through a 3-part cycle: Stage 1 The top chambers (atria) relax and fill up with blood from the veins. Stage 2 The atria contract and the blood is forced into the relaxing bottom chambers (ventricles). Stage 3 The ventricles contract and the blood is forced out of the heart into the arteries.

Circulatory System Learning Objectives: By the end of the lesson you should: Be able to summarise the function of the circulatory system. Be able to summarise the function of the circulatory system. Be able to name at least 6 different parts of the heart. Be able to name at least 6 different parts of the heart. Be able to explain how blood is pumped around the body. Be able to explain how blood is pumped around the body. Homework Using page 39 in your ‘Sport Examined’ books explain how we transport oxygen to our muscles.