Abstract
Structure of the gas of the exchange system
Lungs enclosed in the thorax by the ribcage and the diaphragm (muscular sheet of tissue)
Joining each rib to the next = intercostals muscles
Air passage is highly branching network: called bronchial tree
Air enters our nose/ mouths, passes down the trachea, trachea splits into two tubes called the bronchi leading to each lung. Then bronchus divides into smaller tubers: bronchioles, ending at microscopic air sacs, the alveoli (gas exchange with blood).
Wall of trachea and bronchi contain rings of cartilage: support the airways, keep them open
Thorax separated from the lungs by 2 moist membranes, the pleural membranes (between them: the pleural cavity fill with pleural fluid => lubricate so lungs don't stick to the chest)
In large airways: cells clean by secreting mucus
Other cells cover with cilia: beat backward/forwards sweeping the mucus and trapped particles out towards the mouth
