The heart and circulation

• Path of blood in humans:

  deoxygenate blood - heart to lungs, collects oxygen

  Oxygenated blood returns to heart

  Heart pumps oxygenated blood to organs where blood transfers oxygen o body cells

  deoxygenated Blood pumps back to heart
• Heart has valves to prevent blood flowing backwards
• Heart has 4 chambers ( right atrium, Right ventricle, Left atrium, left ventricle ) to pump blood around
• blood passes from the heart to the lungs in the pulmonary artery, where it collects oxygen
• The vena cava brings in deoxygenated blood from the body
• oxygenated blood passes from the lungs to the heart in the pulmonary vein
• Oxygenated blood is pumped from the heart to the body in the aorta
• 1. Blood enters the right and left atrium from the vena cava and pulmonary vein
  2. The atria contract and blood is forced into the ventricles
  3. The ventricles contract and force blood into the pulmonary artery and the aorta , and out of the heart
  4. Blood flows to the organs through arteries, and returns through veins
• The left side of the heart has a thicker muscular wall than the right side as left pumps blood to entire body so it needs to provide a greater force and right only pumps to the lungs
• The coronary arteries branch out of the aorta and surround the heart, which provides oxygenated blood to the heart
• • Your resting heart rate is controlled by a group of cells in the right atrium wall that act as a pacemaker
  • These cells produce a small electric impulse which spreads to the surrounding muscle cells, causing to contract