The cardiovascular system is made of the heart, blood vessels and blood The heart is made up of 2 upper chambers – the atria 2 lower chambers – the ventricles
Stage 1 - the atria of the heart fill with blood returning from two key areas. Blood from the body returns via the vena cava into the right atrium and blood from the lungs returns via the pulmonary vein into the left atrium. At this time the heart valves remain shut. Stage 2 - the bicuspid and tricuspid valves open because of the pressure build up in the atria and blood flows into the ventricles, and then the valves shut again Stage 3 – the atria now contract and blood is forced into the ventricles and pressure increases to be greater than that in the aorta and pulmonary artery. Stage 4 – the semi-lunar valves open and the ventricles contract forcing blood into the aorta to go the rest of the body or the pulmonary artery to go to the lungs.
Blood- Used for the transportation of gases, fuels, and minerals, hormones
Blood is made up of:
Red blood are produced in bone marrow and contain haemoglobin, which carries oxygen to body tissues and muscles (99%)
White blood cells fight infection. They are produced in bone marrow, lymph tissue and the spleen. (<1%)
Platelets are cells that help from blood clots to stop bleeding. They are produce in bone marrow. (<1%)
Blood Plasma carries nutrient and also removes waste products. Plasma is 90% water and contains fibrinogen, which assists platelets in blood clotting
There are three types of Blood Vessels
Arteries carry blood away from the heart
Veins returns less-oxygenated blood to the heart
Capillaries “connect arterioles and venules & are the smallest blood vessels
Blood flow through capillaries is controlled by small muscular rings know as pre-capillary sphincters and these can stop blood flowing into capillaries and redirect it to other parts of the body. Blood Pressure is the force exerted by blood against the blood vessel walls Heart Rate – is the amount of times your heart beats, usually measure per minute Systolic Blood Pressure – is the working blood pressure number, on the top of your blood pressure reading. Diastolic Blood Pressure – is the resting blood pressure number, on the bottom of your blood pressure reading.