Cardio-respiratory system

• What is the primary function of the respiratory system?

  The respiratory system transports oxygen into the lungs and diffuses it into the bloodstream.
• What happens to carbon dioxide in the respiratory system?

  Carbon dioxide diffuses from the bloodstream into the alveoli.
• Describe the passage of air into the lungs.

  • Air enters through the mouth and nose.
  • It travels down the trachea.
  • The trachea divides into two bronchi, one for each lung.
  • Each bronchus branches into smaller bronchioles.
  • Air reaches the alveoli where gas exchange occurs.
• What are the small tubes called that branch from the bronchi?

  Bronchioles
• Where does gas exchange take place in the lungs?

  Gas exchange occurs at the alveoli.
• How does diffusion work in the context of gas exchange?

  Diffusion is the movement of gas from an area of high concentration to an area of low concentration.
• What happens to oxygen during gas exchange in the alveoli?

  Oxygen diffuses from the alveoli into the blood.
• What occurs with carbon dioxide during gas exchange in the alveoli?

  Carbon dioxide diffuses from the blood into the alveoli.
• What role does haemoglobin play in the respiratory system?

  Haemoglobin carries oxygen to muscles and carbon dioxide to the lungs.
• How does gas exchange at the muscles differ from gas exchange in the alveoli?

  At the muscles, oxygen enters the muscle from the blood while carbon dioxide enters the blood from the muscle.
• What is the concentration of oxygen in the alveoli compared to the blood?

  There is a high concentration of oxygen in the alveoli and a low concentration in the blood.
• What is the thickness of the walls of capillaries and alveoli?

  Both are very thin, just one cell thick.
• What type of membranes are the walls of capillaries and alveoli made of?

  They are made of semi-permeable membranes.
• Describe the process of gas exchange at the muscles.

  • High concentration of carbon dioxide in the muscle.
  • High concentration of oxygen in the bloodstream.
  • Oxygen diffuses from the bloodstream into the muscles.
  • Carbon dioxide diffuses from the muscles into the blood.
• Left Atrium


  The upper chamber of the heart that receives oxygenated blood from the lungs.
• Right Ventricle


  The lower chamber of the heart that pumps deoxygenated blood from the heart to the lungs.
• Left Ventricle


  The lower chamber of the heart that pumps oxygenated blood from the heart to the rest of the body.
• Pulmonary Valve


  The valve that separates the right ventricle from the pulmonary artery, controlling blood flow to the lungs.
• Blood Vessels

  Arteries (carry oxygenated blood away from the heart), veins (carry deoxygenated blood back to the heart), and capillaries (allow for exchange of oxygen and nutrients between blood and tissues).
• Alveoli


  The tiny air sacs in the lungs where gas exchange occurs, allowing for the exchange of oxygen and carbon dioxide between the air and blood.
• What is the primary function of the respiratory system?

  To transport oxygen from the air into the bloodstream and remove carbon dioxide
• How does oxygen enter the bloodstream?

  Oxygen diffuses from the lungs into the bloodstream
• What is vital capacity?

  The maximum amount of air that can be breathed out after a deep inhalation
• How does regular aerobic exercise affect vital capacity?

  It increases a person's vital capacity
• What is the average breathing rate in a resting adult?

  12 breaths per minute
• What is tidal volume?

  The amount of air breathed in with each normal breath
• What is the average tidal volume?

  0.5 litres (500 ml)
• What is minute ventilation?

  The total volume of air entering the lungs in a minute
• What is the average minute ventilation?

  6 litres per minute
• How is minute ventilation calculated?

  Minute ventilation = breathing rate × tidal volume
• What is the minute ventilation if the breathing rate is 12 breaths per minute and tidal volume is 0.5 litres?

  6 litres per minute
• What happens to tidal volume during exercise?

  Tidal volume increases during exercise
• How does the breathing rate change from rest to exercise?

  Breathing rate increases from 12 to 30 breaths per minute
• What is the tidal volume during exercise compared to rest?

  Tidal volume increases from 0.5 litres to 3 litres during exercise
• How does minute ventilation change from rest to exercise?

  Minute ventilation increases from 6 litres per minute to 90 litres per minute
• What are the key lung volumes and their values at rest and during exercise?

  • Breathing rate:
  • Rest: 12 breaths per minute
  • Exercise: 30 breaths per minute
  • Tidal volume:
  • Rest: 0.5 litres
  • Exercise: 3 litres
  • Minute ventilation:
  • Rest: 6 litres per minute
  • Exercise: 90 litres per minute
• What is the primary function of the respiratory system?

  To transport oxygen from the air into the lungs and diffuse it into the bloodstream
• What happens to carbon dioxide in the respiratory system?

  Carbon dioxide diffuses from the bloodstream into the lungs and is exhaled
• How does the cardio-respiratory system function during exercise?

  • Delivers oxygen to working muscles
  • Removes carbon dioxide from the body
  • Increases breathing depth and rate
  • Increases heart rate to transport oxygen and carbon dioxide
• What physiological changes occur in the body during exercise to meet increased oxygen demand?

  Breathing depth (tidal volume) and rate increase