Respiration and Gas Exchange in Humans

20. The human respiratory system includes epiglottis, trachea, bronchi, bronchioles, alveoli, pleural membranes, ribs, intercostal muscles, diaphragm. These are involved in two functions: ventilation an d exchange of gases.

·       Lungs are enclosed within the Thorax , an air tight cavity

·       At the base of the thorax is a sheet of muscles, the Diaphragm.

·       Air is drawn into the lungs via the trachea which is strengthened by rings of cartilage.

·       in the lungs a pair of  bronchi branch out into bronchioles

·       The exchange surface is the alveoli which are air sacs providing a large surface area.

·       They are thin and moist providing a…