5. Heart rate (or pulse rate) is the number of times your heart beats every minute. It is expressed in beats per minute (bpm). Resting heart rate varies from individual to individual and is affected by fitness. The fitter you are, the lower your resting heart rate will be. A normal resting heart rate is between 60-80 bpm. The average resting heart rate is about 70â75 bpm. You can measure how fast your heart is beating by taking your pulse. This can be done at the wrist or the neck. Count how many times your heart beats in 6 seconds and then multiply by 10.
8. The four chambers of the heart have special names: A lower chamber is called a ventricle. An upper chamber is called an atrium (plural: atria). right atrium right ventricle left atrium left ventricle
11. There are three types of blood vessels , as shown in this magnified part of the circulatory system. Why are there different types of blood vessels? blood from the heart artery carries blood back in to the heart carries blood a way from the heart carries blood to and from the bodyâs cells vein blood to the heart
12. thick outer wall thick inner layer of muscle and elastic fibres narrow central tube (lumen) thin outer wall thin inner layer of muscle and elastic fibres wide central tube (lumen) wall only one cell thick ARTERY VEIN CAPILLARY
13. When blood is flowing against gravity, or when a vein is squeezed by muscle action, there is a risk that blood will flow in the wrong direction. Veins have valves to prevent backflow. blood to the heart backflow prevented The valves allow blood to flow in the correct direction⊠⊠but close if blood starts to flow in the wrong direction. vein valve open vein valve closed
17. thick outer wall thick inner layer of muscle and elastic fibres narrow central tube (lumen) thin outer wall thin inner layer of muscle and elastic fibres wide central tube (lumen) wall only one cell thick ARTERY VEIN CAPILLARY