Memorise Bio

• Right side of heart is deoxygenated blood, while left is oxygenated blood
• The muscular wall contracts the heart and pumps it. It is thicker on the left side of the heart because oxygen needs more pressure to be pumped into the whole body with lots of contractions by the left ventricle. Whereas on the right side, oxygen only travels a short distance to get to the lungs.

  
• The septum keeps oxygenated and deoxygenated blood separated.

  
• The 4 chambers of the heart include the left & right versions of the atrium and ventricle. The atrium and ventricles are separated by a valve to prevent the backflow of blood so that it stays in one direction.

  
• The coronary arteries are on the outside of the heart, which deliver oxygenated blood to the heart cells alongside nutrients while removing waste products.

  A) 1

  B) 2

  
• Route of Blood Through Heart:

  1. Deoxygenated blood from flows through (→) vena cava to the right atrium
  2. Atrium contracts and blood → tricuspid AV valve → the right ventricle
  3. Ventricle contracts → semilunar valve → the pulmonary artery
  4. Blood flows through lungs → capillaries → alveoli where gas exchange happens
  5. Oxygenated blood returns to the heart by the pulmonary vein → left atrium
  6. Atrium contracts and blood → bicuspid AV valve → left ventricle
  7. Ventricle contracts and blood → semilunar valve → aorta

  NOTE: the process of contraction on both sides of the heart happen simultaneously

  
• Normally arteries supply oxygenated blood; the pulmonary artery is the only artery that supplies deoxygenated blood.
• Normally veins supply deoxygenated blood; the pulmonary vein is the only vein that supplies oxygenated blood.
• Low pressure blood flow on right side of the heart prevents damage to the capillaries in the lungs