Cardiovascular

• What are the main components of the cardiovascular system?


  The blood, the heart, blood vessels, and circuits
• What is the primary function of the cardiovascular system?


  To pump blood through blood vessels supplying organs with oxygen and nutrients
• What does blood carry back to the lungs for disposal?


  Carbon dioxide and other waste products
• What happens if blood is lost through injury?


  It can lead to death quickly
• What are the six main functions of blood?

  1. Transport gases (O2 and CO2)
  2. Transport nutrients (glucose and amino acids)
  3. Transport waste (lactic acid and urea)
  4. Maintain temperature (steady 37˚C)
  5. Fight infections (via white blood cells)
  6. Clot wounds (via platelets and fibrin)
• What do red blood cells contain that helps transport oxygen?


  Haemoglobin
• How does blood maintain body temperature?

  By maintaining good circulation
• What role do white blood cells play in the body?


  They help kill pathogens
• What are platelets also known as?


  Thrombocytes
• How many miles of blood vessels are there in the human body?

  Approximately 60,000 miles
• What is the largest artery in the body?

  The aorta
• What happens to blood with each heartbeat?


  It is forced at high pressure along arteries
• Why are arteries muscular and flexible?


  To withstand high pressure and push blood along
• What is the lumen in relation to arteries?


  The space in the middle of the artery
• What occurs in the capillaries?


  Gaseous exchange and nutrient uptake
• How thick are the walls of capillaries?


  Just a single cell thick
• What do arterioles connect to?


  Capillaries
• What do venules merge to form?


  Larger veins
• Why do veins have thinner walls than arteries?


  They do not need to absorb the pressure of the pumping heart
• What assists blood flow in veins against gravity?

  Valve gates
• What type of blood do veins carry back to the heart?

  Deoxygenated blood
• What are the three distinct parts of the circulatory system?

  1. Pulmonary circulation (lungs)
  2. Coronary circulation (heart)
  3. Systemic circulation (rest of the body)
• What prevents back-flow of blood in the heart?

  Valves
• What is the function of the right ventricle?


  To pump blood to the lungs
• What is the function of the left ventricle?


  To pump blood around the whole body
• What does the left atrium receive?


  Oxygenated blood from the lungs
• What is the role of the sinoatrial node (SA node)?


  It initiates the electrical pulse for heart contractions
• What does the atrioventricular node (AV node) do?


  It sends a message to the ventricles to contract
• What are the differences between systole and diastole?


  • Systole: Contraction of atrium or ventricle
  • Diastole: Relaxation of atrium or ventricle
• What is the significance of the cardiac cycle?


  It describes the pressure changes during one complete heartbeat
• What is the function of the pulmonary veins?


  To carry oxygenated blood from the lungs to the heart
• What happens during repolarization of the heart?


  The heart relaxes and fills up with blood
• What happens during depolarization of the heart?


  The heart contracts and empties
• What is the role of the valves in veins?


  To prevent backflow of blood
• How does the structure of arteries differ from veins?


  Arteries have thicker walls and carry blood at higher pressure
• What is the significance of the capillary wall being a single cell thick?


  It allows for efficient gas and nutrient exchange
• What is the function of the kidneys in relation to blood?


  To filter waste products from the blood
• What is the role of the villi in the digestive system?


  To absorb nutrients into the bloodstream
• How does blood flow through the heart?

  It enters via the atria, passes into the ventricles, and is pumped out
• What is the purpose of the heart's valves?


  To ensure blood flows in the right direction