The heart

• What doe the superior vena cava do?

  Transports blood from the head.

  Carries deoxygenated blood from the body to the right atrium.
• What does the inferior vena cava do?

  -Carries deoxygenated blood from the body to the right atrium.

  -Transports blood from rest of body.
• What dos the right atrium do?

  Collects deoxygenated blood and pumps it to the right ventricle.
• What does the right ventricle do?

  Pumps deoxygenated blood to the lungs.
• What does the pulmonary artery do?

  Carries deoxygenated blood from the right ventricle to the lungs.
• What does the septum do?

  Separates the left and right sides of the heart.
• What do the pulmonary veins do?

  Carry oxygenated blood from the lungs to the left atrium.
• What does the left atrium do?

  Collects the oxygenated blood and pumps it to the left ventricle.
• What does the aorta do?

  Carries the oxygenated blood from the left ventricle to the rest of the body.
• What do the atrioventricular valves do?

  Prevent back flow of blood into the atria when the ventricles contract.
• What do the semi lunar valves do?

  Prevent back flow of blood from the arteries into the ventricles.
• What do the canary arteries do?

  They branch off the aorta after it leaves the heart to supply the heart with oxygen.
• Why is the left ventricle thicker?

  To create enough pressure
• What is the diastole cardiac cycle?

  1. Blood returns to heart via pulmonary vein and vena cava.
  2. Atria fill so pressure rises
  3. AV valves pushed open
  4. Blood passes into ventricles
  5. Muscular walls of atria and ventricles relaxed
  6. Pressure in ventricles reduced, lower than in aorta and pulmonary artery
  7. Semi lunar valves close.
• What is the atrial systole cycle?

  1. Atrium walls muscle contract
  2. Remaining blood forced into ventricles
  3. Thin muscular walls and last 0.1 seconds
  4. Muscle of ventricle walls remains relaxed.
• What is the ventricular systole cycle?

  1. Ventricular walls contract simultaneously
  2. Blood pressure in ventricle increases
  3. AV valves forced shut
  4. Further increase in pressure
  5. Semi lunar valves forced open
  6. Blood pushed into aorta and pulmonary artery.
• What do pocket valves do?

  Ensure that veins are squeezed, blood flows back towards the heart instead of away from it.
• What happens when pressure is greater on the convex side?

  The tendons would let the blood in.
• What happens when pressure is greater on the concave side?

  The cusps would flatten.
• What are tendons for?

  They allow us to move by connecting muscle to bone.
• What is the formula for cardiac output?


  Cardiac volume = heart rate x stroke volume.
• What is atheroma?


  A fatty deposit that forms within the wall of an artery

  It begins with fat streaks which then enlarge into atheromatous plaque.

  Its more common in larger arteries and narrow them to reduce blood flow.
• What is Thrombosis?


  When an atheroma breaks through, a rough irregular surface forms meaning that smooth blood flow is interrupted causing a blood clot (thrombus). It can block the blood vessel or get carried to a different location and block a different artery.
• What is an aneurysm?

  Atheromas that lead to thromboses also weaken artery walls these weakened points swell to form a balloon like blood filled structure called an aneurysm.

  They frequently burst leading.to haemorrhage and therefore loss of blood in that region.

  An aneurysm in the brain is known as a stroke.
• What is a myocardial infarction?

  -Known as a heart attack

  -Reduced supply of oxygen to the muscle of the heart

  -Caused by blockage in arteries.

  -When it occurs close to the contrary artery and aorta so the heart stops beating.

  -Blockage further along the contrary artery may cause milder symptoms as a smaller area of muscle will suffer the oxygen deprivation.
• What are risk factors for heart disease?

  -Smoking

  -High blood pressure

  -Blood cholesterol level

  -Diet