cardiovascular system

• the cardiovascular system transport, clotting, temperature control
• blood transports oxygen (release energy stored as glucose) carbon dioxide (waste products removed) nutrients
• bloods clots platelets clot blood forming scabs to stop bleeding and heal the body
• blood controls temperature vasodilation (too hot) vasoconstriction (too cold) to maintain optimal temperature for the body to work efficiently
• atria collects blood as it comes into the heart
• ventricles pump blood out of the heart
• valves makes sure that blood doesn’t flow backwards
• septum divides the heart into two halves
• adrenaline is a hormone that makes the heart beat faster during exercise
• adrenaline causes glycogen to be released by the liver and diverts blood away from the organs to the muscles during exercises
• heart blood flow

  vena cava -> right atrium-> triscuspid valve-> right ventricle-> semi-lunar valve -> pulmonary artery-> lungs -> pulmonary veins -> left atrium->bicuspid valve-> left ventricle -> aorta -> body
• arteries transport oxygenated blood from the heart to all parts of the body
• arteries have thick muscle and elastic walls to pump blood under high pressure
• veins transport blood from all parts of the body to the heart
• veins have thinner muscle and elastic walls than arteries as blood is being pumped under less pressure
• capillaries transport blood through the body delivering oxygen to cells and removing carbon dioxide
• capillaries have thin walls to allow gas exchange to take place
• haemoglobin is part of red blood cells
• arteries have small lumens
• veins have valves
• veins have large lumen
• heart rate is the speed that the heart beats
• stoke volume is the volume of blood pumped out of the left ventricle during each systolic cardiac contractions
• cardiac output is the quantity of blood pumped by the heart in a given minute (measured in L/min =stroke volume x heart rate)
• blood pressure is the pressure of the blood in the circulatory system
• diastole the phase of the heart beat when the heart muscle relaxes and allows the chambers to fill with blood
• systole the phase of the heartbeat when the heart muscle contracts and pumps blood from the chambers into the arteries
• vascular shunting the redistribution of blood flow
• vascular shunting increases blood flow to active areas and diverts blood away from inactive areas during exercise
• at rest there is roughly 80% blood flow to the organs
• during exercise there is increased blood flow to muscles (oxygen supply) skin (temperature control) and coronary heart vessels (due to increased blood flow/heart rate )
• during exercise there is decreased blood flow to organs that are not a priority
• vasodilation is the widening of blood vessels caused by the muscle cells relaxing resulting in the lumen becoming wider and blood flow increase
• vasoconstriction is the narrowing of blood vessels by the muscle cells contracting resulting in the lumen becoming narrow and blood flow decreasing
• blood flow is the volume of blood travelling through a vessel
• vasodilation needs to take place during exercise so skeletal muscles have higher blood flow and so more oxygen for respiration
• vasoconstriction needs to happen during exercise because it means there is less blood flow to the liver and digestive system which is less important during exercise and there is more blood for the skeletal muscles
• red blood cells make up 45-50% of the blood in our body
• red blood cells carry oxygen and carbon dioxide
• red blood cells have haemoglobin which is what makes them red