blood circulation

• Circulatory system transport oxygen , digested food substances and waste substances all around our body.
• The circulatory system is made up of the heart, blood vessels and blood
• function of heart

  muscular organ that pumps blood throughout the body
• function of blood

  transport oxygen , digested food substances and carbon dioxide, around our body.
• function of blood vessels

  tubes that carry blood around our body
• arteries transport blood towards the tissue and away from the heart and have thick muscular walls that can withstand blood under high pressure
• veins transport blood back to the heart and are thinner than arteries because they do not need to withstand as much pressure
• capillaries connect arteries and veins and allow exchange between cells and blood
• blood is made up of plasma (liquid), red blood cells, white blood cells and platelets
• red blood cells contain haemoglobin which carries oxygen around the body
• white blood cells fight infection by engulfing bacteria or viruses
• platelets clot blood when we cut ourselves
• white blood cells fight infection by engulfing pathogens or producing antibodies
• the right side of the heart pumps deoxygenated blood to the lungs where it picks up oxygen and releases carbon dioxide
• the left side of the heart receives oxygen rich blood from the lungs and pumps it out to the rest of the body
• arteries carry blood away from the heart
• the left side of the heart receives oxygen rich blood from the lungs and then pumps this out into the rest of the body
• veins carry blood towards the heart
• blood is pumped around the body through a network of tubes called blood vessels
• capillaries are tiny vessels that connect arteries with veins, they allow exchange between tissues and blood
• the walls of arteries are thicker than those of veins because they have to withstand high pressure as they leave the heart
• plasma transports digested food substances and waste substances in body
• red blood cells transport oxygen from the lungs throughout the body
• white blood cells can detect and reject foreign tissues or organs in body. this is not desirable if a transplanted tissue or organ were to be rejected by body.
• heart rate is the number of times the heart beats in one minute
• pulse rate pushes blood out of the heart into the arteries, creating a pulse.
• blood pressure is the force of blood pushing against artery walls as it moves through
• when exercising, our muscles require more energy. to obtain more energy, our muscle cells require extra oxygen, which help release energy from the food we consume
• our heart and pulse rate increase, heart beat faster so blood can carry more oxygen to muscle
• breathing rate increase, to breathe faster, to take in more oxygen and remove carbon dioxide
• when a blood vessel is blocked, blood flow can slow or stop, leading to cells not getting sufficient oxygen and digested food substances. leading to death due to insufficient energy, resulting in serious health problems.
• blockages in blood vessels occur when fats and cholesterol accumulate in the walls of arteries, forming plaque.
• plaque in arteries narrows them, reducing or stop blood flow
• if there plaque in the artery supplying blood to the heart muscles, it can decrease blood flow and oxygen supply, heart attack may occur
• a blockage in artery supplying blood to the brain can lead o reduced oxygen supply, stroke may occur
• diet high in fat increase rick of developing heart disease and stroke.
• high intake of salt increase risk of developing high blood pressure
• level of physical activity can affect. risk of developing
• level of physical activity can affect risk of developing heart disease, high blood pressure and stroke
• smoking increase risk of developing heart diseases, high blood pressure and stroke