Respiratory System

• Pathway of air:

  • mouth and nose
  • larynx
  • trachea
  • bronchi
  • bronchioles
  • alveoli
  • bloodstream
• gaseous exchange happens at the alveoli
• alveoli are adapted for gaseous exchange:

  • large surface area
  • thin walls
  • covered in capillaries
• Breathing rate increases during exercise, this is because there is a greater demand for oxygen at muscles
• tidal volume is the amount of air which enters the lungs during inhalation at rest
• minute ventilation is the volume of gas inhaled or exhaled from the lungs per minute
• long term benefits of exercise on the respiratory system:

  • increase in capillary density
  • increase vital capacity
  • increased tidal volume
  • greater strength of intercostal muscles and diaphragm
  • more efficient gas exchange
  • capillarisation
• 1500m is an aerobic activity
• the waste products of aerobic respiration are carbon dioxide and water vapour
• an example of anaerobic activity is sprinting, throwing, jumping
• lactic acid is a waste product of anerobic respiration
• lactic acid is broken down through oxygen
• mechanics of breathing, inhalation:

  • diaphragm contracts, down and in
  • intercostal muscles contract, ribcage up and out
  • greater lung capacity
• mechanics of breathing, exhalation:

  • diaphragm relaxes, moves up
  • intercostal muscles relax, moving the ribcage down and in
  • smaller lung capacity