Week 4 Respiratory System

• The cells of the respiratory system require a constant supply of oxygen to sustain life and produce energy
• Components of the respiratory system


  • Mouth
  • Nose
  • Airways
  • Lungs
• Cellular Respiration


  O2 + sugar -> CO2 + H2O + Energy
• Sections of the pharynx

  • Nasopharynx
  • Oropharynx
  • Laryngopharynx
• Nasopharynx


  • Traps pollutants / pathogens in the mucus to be moved by cilia out of the body or down to the stomach
• Oropharynx


  Connects the nasopharynx and the laryngopharynx
• Laryngopharynx


  Section splitting the oesophagus and the trachea
• Larynx


  Voicebox protected by epiglottis, protecting cartilage
• Airflow through the respiratory system


  Trachea -> Left and right bronchi -> Bronchioles -> Alveoli
• Alveoli


  • Air sacs covered with capillaries (High surface area) allowing for efficient gas exchange
• Lungs


  • Protected by the pleural membrane, separated into the membrane that covers the lungs (visceral pleura) and the membrane covering the thoracic cavity (parietal pleura)
  • Separated into lobes (3 for right, 2 for left)
• Lung processes


  • Pulmonary Ventilation (breathing)
  • Pulmonary Diffusion
  • Transport of Gases
  • Internal Respiration (rest of the body's gas exchange)
• Inspiration


  Ribs expand upwards and outwards and the pressure in our lungs drops, drawing air in
• Expiration


  Space inside the lung decreases and air is exhaled
• Diaphragm


  Contracts as we inhale to create space, relaxes and moves back upwards when we exhale
• Spirogram measurements


  • Tidal volume
  • Inspiratory reserve
  • Expiratory Reserve
• Lung Capacities


  • Inspiratory Capacity
  • Functional Residual Capacity
  • Vital Capacity
  • Total Lung Capacity
• When we start exercising

  We go into an oxygen deficit as our body does not receive enough for its needs
• After a period of time

  The body reaches a steady state (enough oxygen consumed for its needs)
• In recovery


  An oxygen debt is paid for the oxygen deficit
• Arteriovenous Oxygen Difference


  The difference in oxygen volume per 100 mL of arterial and venous blood
• At rest the arteriovenous oxygen difference is about 5mL (20 vs 15), during exercise this difference increases
• Breathing Control


  Regulated in the brain stem by the medulla and pans which detect CO2 and O2 concentrations