Human Transport

• Plasma is the liquid bit of blood
• Plasma holds in

  • Red and white blood cells and platelets
  • Digested food products
  • Carbon dioxide
  • Urea
  • Hormones
• Red blood cells transport oxygen from the lungs too all the cells in the body
• The red blood cells are well adapted to there function as they

  • Have a biconcave shape to give a large surface area for absorbing and releasing oxygen.
  • They contain haemoglobin, which gives blood it's colour, it contains lots of iron, In the lungs, haemoglobin reacts with oxygen to form oxyhaemoglobin.
  • Red blood cells don't have a nucleus, so they have more space for haemoglobin and therefore can carry more oxygen
• There are two different types of white blood cell you need to know about: phagocytes and lymphocytes
• Phagocytes ingest pathogens, they engulf then digest them
• Arteries: these carry blood away from the heart
• Capillaries: these are involved in the exchange of materials at the tissues
• Veins: These carry the blood to the heart
• Arteries have thick walls as they have to carry blood under pressure. Small Lumen and elastic fibres. Thick layers of muscles
• Arteries branch into capillaries. Capillaires are really tiny. They carry blood really close to every cell in the body to exchange substances with them. They have permeable walls so substances can diffuse in and out. They supply food and oxygen, take away waste like co2. Walls are only one cell thick, increases rate of diffusion by decreasing distance
• Veins take blood back to the heart. Cappilarries eventually join up to form veins. The blood is at lower pressure in the viens si the walls don;t need to be as thich as artery walls. They have bigger lumen then arteries to help the blood flow despite the lower pressure. They also have valves to help keep the blood flowing in the right direction.
• The largest vein in the body is the vena cava
• the largest artery in the body is the aorta
• Lymphocytes produce antibodies.
• Every pathogen has unique molecules called antigens on its surface.
• When white blood cells come across a foreign antigen, they produce antibodies that lock onto the invading pathogens and mark them for destruction by other white blood cells.
• The antibodies produced are specific to that type of antigen and won't lock onto any others.
• Memory cells are also produced in response to a foreign antigen.
• Memory cells remain in the body and remember a specific antigen.
• If the same antigen enters the body again, memory cells can reproduce quickly.
• The right artrium of the heart receives deoxygenated blood from the body (through the vena cava)
• The deoxygenated blood moves through the right ventricle which pumps it to the lungs (via the pulmonary artery)
• The left atrium receives oxygenated blood from the lungs (through the pumonary vein)
• The oxygenated blood then moves through the left ventricle which pumps it out round the whole body (via the aorta)
• The left ventricle has a much thicker wall than the right ventricle. It needs more muscle because it has to pump blood around the whole body, where as the right ventricle only has to pump it to the lungs. This also means that the blood in the left ventricle is under higher pressure than the blood in the right ventricle.
• The valves prevent the backflow of blood
• When you excersise, your muscles need more energy so you respire more.
• You need to get more oxygen into the cells and remove more carbon dioxide. For this to happen the blood has to flow faster, so your heart rate increases
• When an organism is threatened, the adrenal glands release adrenaline. Adrenaline binds to specific receptors in the heart. This causes the cardiac muscle to contract more frequently and with more force, so heart rate increases and the heart pumps more blood. The increases oxygen supply to the tissues, getting the body ready.
• pulmonary means to do with the lungs
• hepatic means to do with the liver
• renal means to do with the kindey
• Arteries usually carry oxygenated blood and veins carry deoxygenated blood
• The pulmonary artery carries deoxygenated blood and the pulmonary vein carries oxygenated blood
• • Cornary heart disease is when the coronary arteries that supply the blood to the muscles of the heart get blocked by layers of fatty materials
  • This causes the arteries to become narrow so blood flow is restricted and there's a lack of oxygen to the heart muscles- this can lead to a heart attack
• There are many risk factors for coronary heart disease, some are:

  • Having a diet high in saturated fats.
  • Smoking increases blood pressure which can cause damage to the inside of the cornary artery.
  • Being inactive can lead to high blood pressure which can damge the lining of arteries.