The heart

• pulmonary = lungs
• vein = in
• Artery = away
• tricuspid valve = right
• bicuspid valve = left
• valves prevent backflow of blood
• pulmonary artery takes blood to the lungs --> to get more oxygen
• pulmonary vein = only vein with oxygenated blood (back from lungs)
• pulmonary artery = only artery to carry deoxygenated blood
• aorta = extremely high pressure
• no valves = blood pressure so high backflow cannot happen
• left side = thicker muscles --> to pump blood further around body + at higher pressure
• right side = thinner muscles --> only has to pump blood to lungs (close) + not so high pressure
• vena cava = vein
• atria = plural for atrium
• Vena cava -> right atrium -> right ventricle -> pulmonary artery -> lungs -> pulmonary vein -> left atrium -> left ventricle -> aorta -> around body organs -> back to vena cava
• blood becomes deoxygenated due to respiring organs (O2 = aerobic respiration = ATP)
• systematic circuit = whole body
• pulmonary circuit = lungs
• Atria & Ventricles contract -> high pressure -> open/close valves
• blood gets reoxygenated from the oxygen in the alveoli in the lungs
• muscle contracts = increasing pressure
• heart = muscle
• double circulatory system = blood passes through heart twice in one cycle
• REASON FOR DOUBLE CIRC SYS = blood enters lungs: decreased blood pressure for diffusion in alveoli -not enough pressure to travel through whole body -> back to heart so pressure can increase
• systematic circuit = higher pressure ( left = thicker walls can pump b further)
• Aorta -> coronary arteries : provide heart muscle with oxygenated blood = can carry out resp + produce ATP to contract
• label this heart:

  A) vena cava

  B) pulmonary vein

  C) pulmonary artery

  D) aorta

  E) left ventricle

  F) left atrium

  G) right atrium

  H) right ventricle

  I) tricuspid valve

  J) bicuspid valve

  K) semi-lunar valves

  L) right

  M) left

  
• why does the left ventricle have a thicker muscle wall than the right ventricle?

  to pump blood further around the body at a higher pressure
• why is the right ventricle's muscle wall thinner?

  it transports blood to lungs, which is a shorter distance than what the left ventricle transports blood to - the entire body - so needs less pressure
• why is the blood pumped in the systematc circuit at a higher pressure than the pulmonary circuit?


  the thicker muscle walls of the left ventricle allow blood to be pumped at a further distance and higher pressure