6.4.4Type I pneumocytes are extremely thin alveolar cells that are adapted tocarry out gas exchange.
6.4.5Type II pneumocytes secrete a solution containing surfactant that creates a moist surface inside the alveoli to prevent the sides of the alveolus adhering to each other by reducing surface tension.
6.4.3Ventilation maintains concentration gradients of oxygen and carbon dioxide between air in alveoli and blood flowing in adjacent capillaries.
6.4.1The lungs are actively ventilated to ensure that gas exchange can occur passively.
6.4.6Air is carried to the lungs in the trachea and bronchi and then to the alveoli in bronchioles.
6.4.7Muscle contractions cause the pressure changes inside the thorax that force air in and out of the lungs to ventilate them.
6.4.8Different muscles are required for inspiration and expiration because muscles only do work when they contract.
6.4.9Causes and consequences of lung cancer.
6.4.2Obtain evidence for theories—epidemiological studies have contributed to our understanding of the causes of lung cancer. (1.8)
6.4.10Causes and consequences of emphysema.