mass transport

• transpiration is the loss of water which is caused by evaporation and diffusion and it happens in the leaves
• blood is made out of red blood cells, white blood cells, plasma and platelets
• red blood cells contains haemoglobin which it carries oxygen, it also has a biconcave shape and do not have a nucleus
• white blood cells defends against infections, changes shape and has a nucleus
• plasma is the liquid part of the body which carries everything
• platelets help blood clot and stop microorganisms getting in, it has no nucleus
• veins have valves to keep the blood flowing in the right direction, the blood is at lower pressure so the walls do not need to be as thick, they also have a bigger lumen to help the blood flow
• arteries have thick walls which contains muscles and elastic fibres, it carries the blood away from the heart and the blood pumps out with high pressure
• capillaries are really small, they have a one cell thick wall and are permeable. they carry blood really close and takes away waste, it also exchange substances with tissues
• the heart contains 4 chambers :

  • right atrium
  • left atrium
  • right ventricle
  • left ventricle
• the heart contrasts to pump blood and it is a pumping muscle organ, they also have valves to avoid the back flow of blood
• right =

  1. deoxygenated blood
  2. pulmonary artery
  3. vena cava

  left =

  1. oxygenated blood
  2. pulmonary vein
  3. aorta
• the alveoli carries out gas exchange in the body, it iii made up of a network of capillaries
• deoxygenated blood → lungs → heart → the whole body
• humans have a double circulatory system which contains the heart, blood vessels and blood
• cardiovascular disease is when the coronary arteries got blocked by layers of fat, it causes the arteries to become narrower and theres a lack of oxygen to the heart muscles, it could lead to heart attack
• stents are tubes that are inserted into the arteries to keep them open
• statins are drugs that reduce the amount of bad cholesterol
• artificial blood, faulty heart valves and temporary heart can also be a method to trip cardiovascular disease
• deoxygenated blood → vena cava → right atrium → contracts into the right ventricle→ contracts and blood is being pushed into the pulmonary artery → into the lungs → deoxygenated blood is being oxidised→ oxygenated blood is being pumped back to the heart through the pulmonary vein → left atrium → into the left ventricle →aorta → the whole body