Respiratory System

• Breathing rate - the number of breaths taken per minute (inspiration/expiration)

  measured in breaths per minute
• Tidal volume - the volume of air inspired or expired per breath

  measure in litres
• minute ventilation - the volume of air inspired or expired per minute

  measured in litres per minute
• minute ventilation = tidal volume X breathing rate
• external intercostals - muscles located between the ribs.

  contract during inspiration and relax during expiration
• diaphragm - sits below the lungs. contracts and flattens during inspiration and relaxes and moves back and up during expiration
• sternocleidomastoid - neck muscle

  contracts during inspiration but only during exercise
• pectoralis minor

  • contracts during inspiration but only during exercise
• internal intercostal muscles - contracts to pull ribs closer together and flattens them

  contracts during expiration but only during exercise
• Rectus abdominus

  • contracts during expiration but only during exercise
• respiratory control centre -  it controls your breathing by sending signals down your spine to your breathing muscles
• external respiration - gaseous exchange of oxygen and carbon dioxide that occurs at the lungs between the alveoli and the blood
• internal respiration - gaseous exchange of oxygen and carbon dioxide that occurs at the muscles between the blood and the muscles
• Gaseous exchange - the movement of oxygen from the alveoli into the blood stream and carbon dioxide from the blood into the alveoli
• Partial pressure - The pressure exerted by a single gas when it exists within a mixture of gases.
• Diffusion - Molecules move from an area of high concentration to an area of low concentration
• Diffusion gradient - The steeper this gradient, the faster the diffusion occurs.
• Dissociation - the process by which oxygen is released from haemoglobin
• association - the process by which haemoglobin binds with oxygen. Occurs in the lungs
• bohr shift - the movement of oxygen dissociation curve to the right of the normal

  occurs due to increased levels of carbon dioxide
• nasal cavity - hairs and mucus filter and aslo warm air
• pharynx, larynx and trachea - mucous membrane and ciliated cells, to moisten, warm and filter air

  trachea has rings of cartilage to keep open
• lungs - located in the thoracic cavity, plural membrane so no friction against ribcage and lungs
• Breathing rate at rest for an untrained person: 12-15 breaths per minute
• Breathing rate at rest for an trained person: 11-12 breaths per minute
• Tidal volume at rest for an untrained person: 0.5 litres
• Tidal volume at rest for an trained person: 0.5 litres
• minute ventilation at rest for an untrained person: 6-7.5 litres per minute
• Minute Ventilation at rest for a trained person: 5.5-6 litres per minute
• Breathing rate for an untrained person at maximal: 40-50 breaths per minute
• Breathing rate for a trained person at maximal: 50-60 breaths per minute
• Tidal volume for an untrained person at maximal: 2.5-3 litres]
• Tidal volume for a trained person at maximal: 3-3.5 litres
• Minute Ventilation for an untrained person at maximal: 100-150 litres per minute
• Minute Ventilation for a trained person at maximal: 160-210 litres per minute
• Why does a trained person have a lower minute ventilation at rest?

  • more efficient gaseous exchange due to larger alveoli
  • more efficient transport of oxygen as there are more red blood cells
  • more efficient use of oxygen in the muscles as there are more mitochondria and myoglobin
• How is oxygen transported in the blood?

  1. combined with haemoglobin in the red blood cells to produce oxyhemoglobin (Hb + O2 = HBO2)- 97%
  2. dissolved in blood plasma - 3%
• Hw is carbon dioxide transported in the blood?

  1. dissolved in water as a carbonic acid - 70%
  2. combines with haemoglobin to create carbaminohaemoglobin - 23%
  3. dissolved in blood plasma - 7%
• Good oxygen and carbon dioxide transport aids exercise because:

  • prolongs the duration of aerobic activity
  • delays anaerobic threshold
  • increases possible intensity/work rate of the activity
  • increases recovery during and after
• Larynx - the voice box which makes sound for speaking