Bbc bitesize cardiovascular system

All blood vessels are specifically structured to perform their function.

The heart is working hard to pump blood around the body. Well, the blood has to be kept moving around all the time because it's the body's delivery system. Every possible part of the body has to be supplied with oxygen and food and water, and the veins and arteries are like roads going all the way through your body with the blood cells like delivery vans. So it's a good job we've got the circulatory system to transport nutrients, water and oxygen to the entire body. Your heart is a very strong muscle which contracts gets smaller and relaxes to pump blood around your body. A heart beat varies from person to person - for an average person it beats times a minute.

Bbc bitesize cardiovascular system

The right side pumps deoxygenated close deoxygenated Blood that is low in oxygen as cells have used it and high in carbon dioxide as cells have produced it. The left side pumps oxygenated close oxygenated Blood that is high in oxygen and low in carbon dioxide. This unidirectional flow of blood through the heart shows that mammals have a double circulatory system. Ventricular walls are thicker than atrial walls because the ventricles have to pump blood further. The left ventricle wall is thicker than the right because it pumps blood around the body while the right pumps blood to the lungs, located close to the heart. The coronary arteries provide the heart muscle with the glucose and oxygen it needs for respiration close respiration The chemical change that takes place inside living cells, which uses glucose and oxygen to release the energy that organisms need to live. Carbon dioxide is a by-product of respiration. These are small blood vessels that branch off the aorta and can be seen on the external surface of the heart. In this guide. Components The blood vessels The heart The effects of exercise.

This means it is under high pressure close high pressure Gases and liquids are under high pressure when their volume has been reduced and so they exert a force against the structure surrounding them, bbc bitesize cardiovascular system. There are four main blood vessels that take blood into and out of the heart.

In the heat, blood vessels close to the surface of the skin enlarge. This process is called vasodilation close vasodilation The increase in diameter of the skin arterioles to increase blood flow and increase heat loss by radiation. This allows more heat to be lost from the blood. When a person takes part in exercise their face can become pink due to vasodilation of the blood vessels close to the skin's surface. In the cold, blood vessels at the skin's surface close. This process is called vasoconstriction close vasoconstriction The narrowing of the skin arterioles to reduce blood flow and reduce heat loss by radiation. Systolic is when the heart contracts and diastolic is when the heart relaxes.

Heart rate is measured in beats per minute bpm. During exercise the heart rate increases so that sufficient blood is taken to the working muscles to provide them with enough nutrients and oxygen. An increase in heart rate also allows for waste products to be removed. Stroke volume increases which means more blood is pumped out of the heart each time it contracts. At rest a person's cardiac output is approximately 5 litres per minute, while during exercise it can increase to as much as 30 litres per minute as both their heart rate and stroke volume increase.

Bbc bitesize cardiovascular system

Blood transports materials and heat around the body and helps to protect against disease. It contains:. You have about 5. An easy way to remember this is: A rteries A way or Ve in In. Blood full of oxygen is called oxygenated blood. Blood with oxygen removed is called deoxygenated blood. So, a rteries carry oxygenated blood a way from the heart, veins carry deoxygenated blood back to the heart. One important exception: unlike all other arteries and veins, the pulmonary artery from the heart to the lungs carries blood with oxygen removed and the pulmonary vein from the lungs to the heart carries blood full of oxygen. The arteries carry blood away from the heart.

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Components The blood vessels The heart The effects of exercise. More guides on this topic. The heart with the arteries, veins and capillaries. In this guide. Related links. The main v ein is the v ena cava. This process is called vasoconstriction close vasoconstriction The narrowing of the skin arterioles to reduce blood flow and reduce heat loss by radiation. The heart has four chambers and a thick muscular wall. This allows more heat to be lost from the blood. Stroke volume SV is the amount of blood pumped out of the ventricles each time they contract. Ventricular walls are thicker than atrial walls because the ventricles have to pump blood further. Capillaries are tiny blood vessels that branch into all tissues. This has the effect of taking more oxygen into the body and removing more carbon dioxide.

All blood vessels are specifically structured to perform their function. For example, a capillary is microscopically thin to allow gases to exchange, the arteries are tough and flexible to cope with high pressure blood flow and the veins contain valves to prevent the blood from travelling backwards when at low pressure. All vessels feature varying lumen size.

Inside you, there is an amazing network of blood vessels, the tubes that carry blood all around your body. During sport and physical activity, HR, SV and therefore Q, all increase to send more blood and oxygen to the working muscles. When the heart contracts it pushes blood into blood vessels which creates blood pressure. The main function of blood is to transport nutrients and oxygen to the cells of the body. Because the blood is under lower pressure, one-way valves in your veins stop it flowing backwards. Capillaries close capillaries Tiny blood vessels which carry blood into and out of all tissues in the body. Blood vessel Pulmonary vein Function Carries oxygenated blood from the lungs to the heart. They need these because the blood is under lower pressure returning to the heart. The ventricles pump the blood out of the heart to the lungs or around the body. In the heat, blood vessels close to the surface of the skin enlarge.