Structure of the Human gas-exchange system

Structure of the Human gas-exchange system

1. Our lungs act as an interface (site of gas exchange)

   • This means that gases diffuse in and out when we breathe durin inspiriation and expiriation
   • The function and efficiency of the lungs can be affected by pathogens and lifestyle
     • e.g. smoking
     • They can also be effected by: 1. Partial pressure difference 2. Membrane thickness 3. Surface area of gas exchange 4. Ventilation-perfusion ratio

2. Respiration

   • During respiration, it is fundamental that the volume of oxygen that has been absorbed and the volume of carbon dioxide removed occurs largely in mammals
     • This is because....
       • 1. They have a large volume of living cells
       • 2. They maintain a high body temp and therefore have high metabolic and respiratory rates
       • Mammals have evolved to have specialised surfaces (lungs) which ensure the efficient gas exchange between the air and the blood
   • Aerobic (requires oxygen)
     • glucose + O2 ------> CO2 + O2 + Energy (in the form of ATP)

3. Structure

   • The lungs are located in the inside of the body, this is because:
     • Air is not dense enough to support the delicate structures
       • They would loose large amounts of water and eventually dry out
   • The lungs are supported by the rib cage
     • Can be moved by the bony muscle between them

Images and files in the map