Heart and Blood Vessels

• What is the structure of the heart?

  It has muscular walls to provide a strong heartbeat.
• Why is the muscular wall of the left ventricle thicker than the right ventricle?

  Because it needs to pump blood all around the body, not just to the lungs.
• What is the function of the circulatory system?

  To carry oxygen and nutrients to every cell and remove waste products.
• What is the double circulatory system?

  A system where deoxygenated blood flows to the lungs and oxygenated blood flows to the body.
• What happens to deoxygenated blood in the heart?

  It flows into the right atrium and then into the right ventricle, which pumps it to the lungs.
• What happens to oxygenated blood in the heart?

  It flows into the left atrium and then into the left ventricle, which pumps it around the body.
• What is the primary function of the heart?

  To pump blood around the body.
• What is the role of the circulatory system in relation to waste products?

  It removes waste products from the body.
• What is the equation used to calculate the rate of a reaction?

  Rate = change/time
• What is the function of the heart in the circulatory system?

  • Pumps blood around the body
  • Carries oxygen and nutrients to cells
  • Removes waste products
• What does a double circulatory system mean?

  It means there are two circuits for blood flow in the body.
• Describe the flow of deoxygenated blood in the heart.

  1. Flows into the right atrium
  2. Moves to the right ventricle
  3. Pumped to the lungs for gaseous exchange
• Describe the flow of oxygenated blood in the heart.

  1. Flows into the left atrium
  2. Moves to the left ventricle
  3. Pumped around the body
• What is the structure of the heart?

  The heart has muscular walls, 4 chambers, and valves.
• Why is the muscular wall of the left ventricle thicker than the right ventricle?

  It needs to pump blood all around the body, not just to the lungs.
• What is the function of valves in the heart?

  To ensure blood does not flow backwards.
• What do coronary arteries do?

  They provide the heart with its own oxygenated blood supply.
• What is the process of blood flow through the heart?

  1. Blood enters right atrium via vena cava and left atrium via pulmonary vein.
  2. Atria contract, forcing blood into ventricles.
  3. Ventricles contract, pushing blood to lungs (right) and body (left).
  4. Valves close to prevent backflow.
• What controls the natural resting heart rate?

  A group of cells in the right atrium acts as a pacemaker.
• What is the function of an artificial pacemaker?

  It produces a signal to cause the heart to beat at a normal speed.
• What are the three types of blood vessels in the body?

  1. Arteries
  2. Veins
  3. Capillaries
• What are the characteristics of arteries?

  • Carry blood AWAY from the heart
  • Strong muscular walls
  • Elastic fibres to withstand high pressure
• What are the characteristics of veins?

  • Carry blood TOWARDS the heart
  • Wide lumen for low pressure blood
  • Valves to ensure correct blood flow direction
• What are the characteristics of capillaries?

  • Allow close blood flow to cells
  • One cell thick walls for short diffusion pathway
  • Permeable walls for substance movement
• How is the rate of blood flow calculated?

  Rate of blood flow = volume of blood/number of minutes.
• What is the function of the lungs?

  • Supply oxygen to the blood
  • Remove carbon dioxide
• What are the components of the gas exchange system?

  • Trachea
  • Intercostal muscles
  • Bronchi
  • Bronchioles
  • Alveoli
  • Diaphragm
• Describe the process of ventilation.

  1. Ribcage moves up and out; diaphragm moves down.
  2. Volume of chest increases, lowering pressure.
  3. Air is drawn into the chest.
  4. Opposite occurs during exhalation.
• What happens during gas exchange in the alveoli?

  1. Alveoli fill with oxygen upon inhalation.
  2. Deoxygenated blood in capillaries has high carbon dioxide.
  3. Oxygen diffuses into the bloodstream.
  4. Carbon dioxide diffuses from blood to alveoli.
• How are alveoli adapted for gas exchange?

  • Small and clustered for large surface area
  • Capillaries maintain concentration gradient
  • Thin walls for short diffusion pathway
• How is breathing rate calculated?

  Breathing rate = number of breaths/number of minutes.
• Describe the function of the two circuits in a double circulatory system


  1. Deoxygenated blood flows into the right atrium and then into the right ventricle which pumps it to the lungs to undergo gaseous exchange
  2. Oxygenated blood flows into the left atrium and then into the left ventricle which pumps oxygenated blood around the body
• Name structure A and its function:

  Pulmonary artery: takes blood to lungs

  
• Name structure B and it’s function:

  Vena cava: takes the blood from the body

  
• Name structure C and its function:

  Right atrium: where deoxygenated blood flows into

  
• Name structure D and its function 


  Valve- prevents back flow of blood

  
• Name structure F and it’s function:

  Right ventricle: pumps deoxygenated blood to the lungs

  
• Name structure K and it’s function

  Aorta: carry oxygenated blood away from the heart to the rest of the body

  
• Name structure J and it’s function:

  Pulmonary vein: carry oxygenated blood from the lungs back to the heart.

  
• Name the structure I and its function:

  Left atrium: receive oxygenated blood from the pulmonary veins and pump it into the left ventricle.