circulatory system

• Red blood cells:

  • Small and flexible

  • Biconcave shape maximises surface area

  • Thin membrane

  • Haemoglobin binds to oxygen
• White blood cells:

  • Differentiated and irregular shape

  • Increase in numbers
• 1. DEOXYGENATED blood from body enters RIGHT ATRIUM through VENA CAVA.VENTRICLE then to LUNGS
  2. BLOOD passes from RIGHT ATRIUM tO RIGHT VENTRICLE (Atria contract, forcing blood into ventricles via tricuspid valve. ventricles contract, forcing blood into pulmonary artery to lungs).
  3. OXYGENATED blood from lungs enters LEFT ATRIUM through PULMONARY VEIN.
  4. ATRIA contract, forcing blood into the ventricles via the bicuspid value. Ventricles contract forcing blood in Aorta to body.
• Cellular respiration is an exothermic reaction. It releases energy for metabolic processes.
• Aerobic respiration:

  • Needs oxygen

  • Releases lots of energy / most efticient way of energy transfer

  • Respiration occurs in mitochandria & all the time
• Anaerobic respiration:• Releases less energy - less glucose molecule• Lactic acid builds up in muscles = painful, cramp

  • Gives energy bursts / allows muscle contraction without oxygen or glucose.
• CARDIAC OUTPUT = STROKE VOLUME x HEART RATE
• Artery:

  • thick and elastic wall because of high pressure

  • small lumen

  Vein:

  • thin wall

  • large lumen

  • valves when at low pressure

  Capillaries:

  • single cell wall so diffusion is easier
• Vena cava - carries deoxygenated blood from the body to the heart
• Pulmonary artery - carries deoxygenated blood from the heart to the lungs
• Right ventricle - pumps blood into pulmonary arteries to the lungs
• Left ventricle - more muscle and thicker as pumps blood into aorta to the whole body
• Aorta - carries oxygenated blood from the heart to the body
• Pulmonary veins - brings oxygenated blood from lungs to the left atrium
• Valves - stop blood flow so the blood can flow in the right direction