Gas Exchange in Humans
The features
Large Surface area
Thin Surface
Good blood Supply
Good ventilation with air
Lungs
Larynx
Ribs
Intercostal Muscles
Diaphragm
Trachea
Bronchi
Bronchioles
Alveoli
Capillaries
Inspired air
Expired air
Cartilage in the trachea prevents the trachea from falling off
When exhaling, the Diaphragm is flattened; the external intercostal muscles contract; and the ribs rise up and outwards. It increases the volume of thorax and decrease the pressure inside thorax. This allows air outside the body to let in.
When inhaling, the Diaphragm rises up; the internal intercostal muscles contract; and the ribs relax. It decrease the volume of thorax and increase the pressure inside thorax. This forces air inside the body to be out.
O2 > CO2
O2 < CO2
Water Vapour
Protection in gas exchange system
Goblet Cells
Ciliated cells
Produces Mucus to trap pathogens and foreign particles
Moves mucus towards the throat to trap dust and bacteria