Circulatory System

• Through which part of the heart does blood enter?

  Blood enters the heart through the vena cava.
• From which veins does blood enter the right atrium?

  Blood from two vena cavae enters the right atrium.
• Where does blood enter the left atrium from?

  Blood enters the left atrium from pulmonary vein.
• What happens after the atria fill with blood?

  The ventricles fill with blood after the atria.
• What prevents blood from flowing back into the atria?

  Heart valves prevent blood from flowing back into the atria.
• What is the main artery that blood leaves the heart through?

  Blood leaves the heart through the aorta.
• From which side of the heart does blood leave through the pulmonary artery?

  Blood leaves through the pulmonary artery from the right side.
• What is the structure of the human circulatory system?

  • Humans have a double circulatory system.
  • The heart pumps blood through two circuits:
  • Pulmonary circulation
  • Systemic circulation
• What is the function of the pulmonary circulation?

  The pulmonary circulation transports blood to the lungs.
• What happens to oxygen in the lungs during pulmonary circulation?

  Oxygen diffuses into the blood from the alveoli.
• What happens to carbon dioxide in the lungs during pulmonary circulation?

  Carbon dioxide diffuses from the blood into the lungs.
• What does the systemic circulation transport?

  The systemic circulation transports oxygen and nutrients to the body.
• What does the systemic circulation remove from the cells?

  The systemic circulation removes carbon dioxide and other wastes away from cells.
• Why is the pulmonary circulation under lower pressure?

  Because blood is delivered to the lungs only, which are very close to the heart.
• What is the optimum pressure for gas diffusion in a healthy person?

  The lower pressure in pulmonary circulation is optimum for the diffusion of gases.
• How does blood circulate through the heart in one complete circulation of the body?

  1. Deoxygenated blood from the body enters the right atrium.
  2. Atria contract in unison.
  3. Blood is delivered to the body and transported to the lungs simultaneously.
  4. Oxygen is picked up from the lungs while blood is delivered to the body.
• What is the role of the blood during circulation?

  Blood is delivered to the body while also being transported to the lungs.
• What is the role of the circulatory system?

  To transport oxygen and nutrients to the body's tissues
• What is the structure of the circulatory system?

  • Composed of blood, blood vessels, and the heart
  • Functions as a double circulatory system with two loops:

  1. Carries deoxygenated blood to the lungs
  2. Carries oxygenated blood to the rest of the body
• How many chambers does the heart have?

  Four chambers
• What are the names of the top and bottom chambers of the heart?

  The top chambers are called atria and the bottom chambers are called ventricles
• Describe the path blood takes through the heart.

  1. Blood enters via the vena cava and pulmonary vein
  2. Flows into the right atrium (deoxygenated) and left atrium (oxygenated)
  3. Atria contract, pushing blood into ventricles
  4. Ventricles contract, pushing blood into pulmonary artery and aorta
  5. Cycle repeats
• What is the difference between arteries and veins?

  Arteries carry blood away from the heart, while veins carry blood to the heart
• Can arteries carry deoxygenated blood?

  Yes, for example, the pulmonary artery carries deoxygenated blood
• Can veins carry oxygenated blood?

  Yes, for example, the pulmonary vein carries oxygenated blood
• What are coronary arteries?

  Small arteries that supply oxygenated blood to the heart muscle
• What is the overall function of the circulatory system?

  • Transport oxygen and nutrients to tissues
  • Remove waste products from tissues
  • Maintain homeostasis
• What is the primary function of the lungs?

  To get oxygen from the air into the bloodstream
• How is carbon dioxide transported in the blood?

  It is dissolved in the blood plasma
• What happens to the blood during exercise in relation to breathing rate?

  • Breathing rate increases
  • More oxygen is taken in
  • More carbon dioxide is expelled
• What are the properties of veins?


  Bigger lumen than arteries, contains valves, blood is at low pressure
• What are the properties of the arteries?

  Elastic fibres, thick muscular walls, carry oxygenated blood
• What are the properties of capillaries?

  Thin and permeable walls (one cell thick), supplies food and oxygen, very tiny
• What side of the heart carries deoxygenated blood? 


  Right side
• What side of the heart carries oxygenated blood?


  Left side
• What does plasma carry?


  Plasma carries proteins, antibodies, antitoxins,hormones, and waste products.
• What are platelets? 


  Small fragment of cells that have no nucleus which help blood to clot
• What are the functions of white blood cells?

  They produce antibodies to fight pathogens.
• What are disadvantages of stents? 


  risk of complications, risk of heart attack, risk of thrombosis
• What are advantages of stents?


  Effective for a long time, quick recovery time, widens arteries