Post by Admin on Nov 21, 2016 11:48:17 GMT
Blood
• Plasma is the liquid part of the blood.
• Red blood cells are the most numerous blood cells. They are made in bone marrow and they contain haemoglobin to transport oxygen. They also give the blood its red colour.
• Iron is needed to make red blood cells.
• White blood cells fight disease.
• Platelets clot the blood to stop bleeding.
• Red blood cells have a biconcave shape and no nucleus.
The Circulatory System
• The circulatory system consists of the heart and the blood vessels.
Blood Vessels
• Veins bring blood to the heart. They have a wider lumen than arteries, and valves to prevent backflow of blood.
• Arteries carry blood away from the heart. They have a narrow lumen and have no valves.
• Capillaries are thin blood vessels (1 cell thick) that allow substances to pass into and out of the blood. They join veins to arteries.
The Heart
• Made of cardiac muscle - never tires
• Contracts to pump blood around the body
• Consists of 4 chambers - right & left atriums, right & left ventricles.
• Right side of the heart pumps deoxygenated blood to the lungs
• Left side of the heart pumps oxygenated blood to the rest of the body. The heart wall is therefore thicker/stronger on the left.
• Has 2 valves to control the direction of the flow of blood.
Exercise and the rate of heartbeat
• The normal heartbeat rate of a resting human is 70 beats per minute.
• Exercise increases the heartbeat rate. This is because during exercise the cells need to produce more energy, so they require more food and oxygen.
Body Temperature
• The normal body temperature in the human body is 37°C.
• Blood flow helps regulate body temperature.
• Plasma is the liquid part of the blood.
• Red blood cells are the most numerous blood cells. They are made in bone marrow and they contain haemoglobin to transport oxygen. They also give the blood its red colour.
• Iron is needed to make red blood cells.
• White blood cells fight disease.
• Platelets clot the blood to stop bleeding.
• Red blood cells have a biconcave shape and no nucleus.
The Circulatory System
• The circulatory system consists of the heart and the blood vessels.
Blood Vessels
• Veins bring blood to the heart. They have a wider lumen than arteries, and valves to prevent backflow of blood.
• Arteries carry blood away from the heart. They have a narrow lumen and have no valves.
• Capillaries are thin blood vessels (1 cell thick) that allow substances to pass into and out of the blood. They join veins to arteries.
The Heart
• Made of cardiac muscle - never tires
• Contracts to pump blood around the body
• Consists of 4 chambers - right & left atriums, right & left ventricles.
• Right side of the heart pumps deoxygenated blood to the lungs
• Left side of the heart pumps oxygenated blood to the rest of the body. The heart wall is therefore thicker/stronger on the left.
• Has 2 valves to control the direction of the flow of blood.
Exercise and the rate of heartbeat
• The normal heartbeat rate of a resting human is 70 beats per minute.
• Exercise increases the heartbeat rate. This is because during exercise the cells need to produce more energy, so they require more food and oxygen.
Body Temperature
• The normal body temperature in the human body is 37°C.
• Blood flow helps regulate body temperature.