Cardiovascular and Respiratory systems

• What is heart rate?

  Heart rate is the number of times the heart beats per minute.
• What is stroke volume?

  Amount of blood pumped out of left ventricle per beat
• What is cardiac output?

  Amount of blood pumped out of left ventricle per minute
• What is the equation for cardiac output?

  Cardiac output = heart rate x stroke volume
• What are the three major blood vessels that go around the body?

  Arteries

  Veins

  Capillaries
• What are arteries?

  Blood vessels that carry oxygenated blood away from the heart.
• What are veins?

  Blood vessels that carry blood back to the heart.
• What are some differences between arteries and veins?

  Arteries: Carry blood away from the heart at high pressure, have thick muscular walls. Veins: Carry blood towards the heart at low pressure, have valves to prevent backflow.
• What are capillaries?


  Small blood vessels that link the arteries to the veins and allow oxygen and carbon dioxide to pass through their walls.
• What is a feature of capillaries that aids diffusion?

  Walls are one cell thick
• What are red blood cells?

  Carry oxygen from the lungs to the muscles and remove carbon dioxide from the muscles to the lungs.
• What do red blood cells contain?

  Haemoglobin
• What does haemoglobin in red blood cells do?

  Binds with oxygen to form oxyhaemoglobin which means that the cells can carry oxygen within them to muscles
• What would happen if haemoglobin was not in red blood cells?

  Performers would fatigue easily and stop
• What is vascular shunt?

  When blood flow to working muscles rises to meet increase in oxygen demand during exercise.
• What are the two stages of a heart beat?

  Diastole and systole.
• What is diastole?


  When the heart relaxes and fills with blood.
• What is systole?

  When the heart contracts and empties of blood
• What is the pathway of blood to the lungs?

  Vena cava -> right atrium -> tricuspid valve -> right ventricle -> semi-lunar valve -> pulmonary artery -> lungs
• What is the pathway of blood returning from the lungs?

  Pulmonary vein -> left atrium -> bicuspid valve -> left ventricle -> semi-lunar valve -> aorta -> rest of body
• What is the wall that divides the heart into left and right sides called?

  Septum
• What passage does air take through our body?

  Enters via nasal cavity or mouth -> goes through trachea to the bronchi which splits off into bronchioles which have small air sacs called alveoli within them in the lungs
• What does the trachea do?

  Maintains an open airway with cartilage and cilia remove dust.
• What are alveoli?

  Tiny air sacs that allow diffusion as the point of gaseous exchange within the lungs
• What gases diffuse at the alveoli?

  Oxygen enters the bloodstream and carbon dioxide leaves it
• How is the alveoli adapted to help gaseous exchange?

  Covered in capillaries - both have thin walls so gases can easily diffuse through them.

  A large blood supply - increased red blood cell content means more oxygen gets transferred to the muscles and tissues
• What are the mechanics of breathing during inspiration?

  Intercostal muscles contract - lifting ribs upwards and outwards causing the chest to expand. The diaphragm contracts - it flattens. The lungs increases in size as the chest expands and the pressure inside our lungs falls as the chest expands so the higher pressure of air outside the lungs causes the air to be sucked into the lungs via the nose or mouth.
• What are the mechanics of breathing during expiration?

  Intercostal muscles relax so ribs go down and chest shrinks.

  Diaphragm relaxes and returns to domal position and the lungs decrease in size as chest shrinks so pressure inside lungs increases - forcing air out through the nose or mouth.
• What is tidal volume?

  The volume of air inspired or expired per breath.
• What is breathing rate?

  The number of breaths per minute - approx 12-20 for a healthy adult at rest.
• What is minute ventilation?

  Minute ventilation is the total volume of air breathed in and out in one minute.
• What is the equation for minute ventilation?

  Minute ventilation = tidal volume x breathing rate
• What happens to minute ventilation during exercise?

  All 3 (MV,TV,BR) increases as there is a greater need for oxygen in the body and for the removal of carbon dioxide.
• What is aerobic respiration?

  Energy releasing reaction that occurs in the presence of oxygen.

  Glucose + Oxygen --> Energy + Carbon Dioxide + Water
• When does aerobic respiration occur?

  During exercise that can be maintained for long periods of time.

  Moderate intensity with a long duration
• What is anaerobic respiration?

  Energy-releasing reaction that occurs in the absence of oxygen.

  Glucose --> Energy + Lactic Acid
• When does anaerobic respiration occur?

  During exercise at a high intensity for a short period of time, where the respiratory system cannot supply the muscles with sufficient oxygen so lactic acid gets produced along with energy (less produced than in aerobic) and lactic acid causes fatigue.