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This chapter focused on the structures and functions of the respiratory system. The upper and lower respiratory systems were discussed. The upper respiratory system consists of the nose, nasal cavity, mouth, pharynx, and larynx. The upper respiratory system brings air into the body and warms that air before it enters the lungs. The lower respiratory system consists of the trachea and the lungs, which include the bronchi and bronchioles. The lungs are where gas exchange takes place to provide the body with oxygen and expel carbon dioxide.

Common disorders of the upper and lower respiratory system were discussed. Upper respiratory disorders include pharyngitis (sore throat), rhinitis, and sinusitis. Disorders of the lower respiratory system include asthma and the chronic obstructive pulmonary diseases emphysema and chronic bronchitis.

The process of gas exchange, oxygenation, ventilation, perfusion, and diffusion were briefly discussed. Gas exchange is when oxygen moves from the lungs into the bloodstream. Oxygenation is the process of supplying oxygen to the body’s cells. Ventilation is the process of moving air into and out of the lungs, and diffusion is the spontaneous exchange of gases between the alveoli and capillaries in the lungs. Perfusion is blood flow to tissues and organs, which can also be affected by circulation.


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