Components of the circulatory/cardiovascular system The three components are: Heart Blood vessels Blood
Heart Is a muscular pump. The amount of blood pumped can be calculated: heart rate x stroke volume = cardiac output Increases when exercising Has four chambers. Two atria (a chamber or space) collect the blood. Two ventricles (chambers that collect and expel blood received) pump the blood out of the heart. Valves (device that regulates, directs or controls the flow of a fluid by opening ,closing, or partially obstructing various passageways ) prevent the blood from flowing backwards. The septum (a wall) separates the two sides of the heart. The right side of the heart pumps de-oxygenated blood (blood not containing oxygen) to the lungs to pick up oxygen. The left side of the heart pumps the oxygenated blood (blood containing oxygen) from the lungs around the rest of the body.
There are three types of blood vessels: Arteries Carry blood away from the heart Have thick muscular walls Have small passageways for blood Contain blood under high pressure Veins Carry blood to the heart Have thin walls Have larger internal lumen Contain blood under low pressure Have valves to prevent blood flowing backwards Capillaries Found in the muscles and lungs Microscopic – one cell thick Very low blood pressure Where gas exchange takes place. Oxygen passes through the capillary wall and into the tissues, carbon dioxide passes from the tissues into the blood
Blood Is a tissue. Made up of a variety of cells, each having a different job. Is about 80% water and 20% solid. Made mostly of plasma, which is a yellowish liquid that is 90% water. Including the water, plasma contains salts, glucose and other substances. Plasma also contains proteins that carry important nutrients to the body’s cells and strengthen the body’s immune system so it can fight off infection. The average man has between 10 and 12 pints of blood in body. The average woman has between 8 and 9 pints. (8 pints is equal to 1 gallon)
Blood has four key components: Plasma Fluid part of blood Carries carbon dioxide, hormones and waste Red blood cells Contain haemoglobin which carries oxygen Made in the bone marrow. The more you train the more red blood cells are made. White blood cells An important part of the immune system, they produce antibodies and destroy harmful microorganisms Made in the bone marrow
Blood has four key components: Platelets Clump together to form clots Protect the body by stopping bleeding When exercising blood does the following things: Transports nutrients and waste Delivers oxygen to the working muscles Removes heat (temperature regulation) Dilutes/carries away lactic acid (acidic balance) Blood pressure increases when you exercise, but is lower at rest when you are fit. It is also affected by age, smoking, stress, diet and weight.
Fun Facts! If you took all of the blood vessels out of an average child, and laid them out in one line, the line would be over 60,000 miles long! An adults vessels would be closer to 100,000 miles long!