Transport in humans

• Blood is made up of red blood cells, white blood cells, platelets and plasma
• Plasma transports carbon dioxide, urea, heat energy, hormones, and digested food
• Red blood cells adaptations include: no nucleus to make space for the presence of haemoglobin, biconcave shape to increase surface area also flexible so they can easily fit a small capillaries.
• phagocytes digest, and engulf pathogens
• Lymphocytes produce antibodies
• Platelets help blood clot, so when the skin is broken, the bleeding can stop and when it dries a scab will form this protects from blood loss and bacteria entering
• The left ventricle has a thicker muscle to withstand the pressure of pumping blood to the entire body.
• The vena cava brings deoxygenated blood into the right ventricle
• The pulmonary artery takes deoxygenated blood to the lungs
• Pulmonary vein takes oxygenated blood into the heart
• The aorta pumps blood around the body
• The valves in the heart prevent backflow of blood, and the mixing of oxygenated and deoxygenated blood.
• Heart rate increases during exercise to supply the body with more oxygen and glucose for respiring cells
• Anaerobic respiration occurs if exercise becomes more intense
• The hormone adrenaline increases heart rate as a part of the fight or flight response
• After pair of exercise heart rate may remain high as oxygen is required to break down the lactic acid from anaerobic respiration
• Veins - carry deoxygenated blood at low-pressure, they have thin walls and large lumen
• Arteries carry oxygenated blood at high pressure with thick, muscular walls and narrow lumen
• Coronary heart disease is when fatty material (plaque) builds up in the coronary arteries.
• Chemicals and smoke increases the plaque buildup and increases blood pressure.
• High cholesterol and a fatty diet speeds up the buildup of plaque in the arteries.
• The renal artery goes towards the kidney, and the renal vein goes away from the kidney
• Hepatic artery goes towards the liver in the hepatic vein goes away