Respiratory System

• What is the primary function of the respiratory system?

  To breathe air into the lungs
• How does the respiratory system transfer oxygen?

  Through diffusion from lungs to blood
• What happens to carbon dioxide in the respiratory system?

  It diffuses from blood into the lungs
• Why are the functions of the respiratory system more pronounced during physical activities?

  Because the body requires more oxygen
• What structures warm, filter, and moisten incoming air?

  The nose, nasal cavity, and mouth
• What is the pathway of air from the throat to the lungs?

  Throat to trachea to bronchi to bronchioles
• What lines the trachea, bronchi, and bronchioles?

  A mucous membrane and cilia
• What is the role of cilia in the respiratory system?

  To push mucus to the back of the throat
• Where does gas exchange occur in the lungs?

  In the alveolar sacs containing alveoli
• What muscle forms the base of the thoracic cavity?

  The diaphragm
• What happens during inspiration at rest?

  External intercostal muscles and diaphragm contract
• What is the effect of diaphragm contraction during inspiration?

  It increases the volume of the chest cavity
• What occurs during expiration at rest?

  External intercostal muscles and diaphragm relax
• What happens to the ribs during expiration at rest?

  They move back down
• How does inspiration change during exercise?

  Muscles contract faster and more forcefully
• What is the result of increased chest cavity volume during exercise?

  More air rushes into the alveoli
• What additional muscles contract during expiration in exercise?

  Internal intercostal and abdominal muscles
• What happens to oxygen and carbon dioxide during diffusion in the alveoli?

  Oxygen moves into blood; CO2 moves into alveoli
• What is diffusion in the context of respiration?

  The movement of molecules down a concentration gradient
• What is vital capacity?

  The maximum air exhaled after maximal inspiration
• What is the typical vital capacity for men?

  4-5 litres
• How does vital capacity differ for endurance athletes?

  They can have 6-7 litres of vital capacity
• What is minute ventilation?

  The amount of air breathed in and out in one minute
• How is minute ventilation calculated?

  Minute ventilation = tidal volume x frequency
• What is the minute ventilation for an average person at rest?

  28 litres/min
• What is the minute ventilation for an average person when exercising?

  100 litres/min
• Why is it more efficient to increase ventilation through deeper breaths?

  It provides more oxygen than faster breaths
• What does the respiratory centre in the brain detect during exercise?

  Increased levels of carbon dioxide in blood
• What is the response of the respiratory centre to increased carbon dioxide?

  It sends impulses to increase breathing rate
• How does regular aerobic endurance training affect respiratory muscles?

  It makes them stronger
• What happens to vital capacity and minute ventilation with training?

  They can improve with regular training
• How does increased surface area for gaseous exchange benefit athletes?

  More oxygen enters blood; more CO2 exits
• What does increased diffusion capacity allow athletes to do?

  Work longer and harder without tiring
• What is the ventilation rate for an unfit person?

  25 breaths per minute
• How does training affect the number and diameter of capillaries around alveoli?

  They increase in number and diameter
• What are the short-term effects of exercise on the respiratory system?

  • Increased breathing rate
  • Increased depth of breathing
  • Higher minute ventilation
  • More oxygen intake
• What are the long-term effects of optimal training on the respiratory system?

  • Stronger respiratory muscles
  • Improved vital capacity and minute ventilation
  • Increased surface area for gas exchange
  • Enhanced oxygen uptake and carbon dioxide removal