THE PHARYNX (THROAT)- THE LARYNX

THE PHARYNX (THROAT)

From the nasal cavity, air moves into the pharynx, or throat, which ranks as one of the most complex parts of the human body. Seven tubes enter the pharynx: the two from the nasal cavity, called the internal nares; the Eustachian tubes which lead to the ears; the mouth cavity; the opening of the esophagus; and the glottis, the opening of the windpipe. Traffic in the pharynx becomes complex during the eating process. Food and water go down one opening; air must pass through another. 

Fortunately, the traffic control is automatic and things usually go where they should. Tonsils, masses of soft tissue, are located on each side of the pharynx, behind the mouth cavity.

There is also tonsil tissue at the base of the tongue. And adenoids are tonsil-like masses of tissue that grow on the back wall of the pharynx behind the internal nares. It appears that the function of tonsil tissue is to trap and destroy disease organisms, helping to guard the body against infections that may develop from germs entering through the nose or mouth. 

Tonsils become infected rather easily. In some cases, the tonsils may become so diseased that tonsillitis, sore throat, and other respiratory infections become frequent. Then a physician may recommend tonsil removal, although such removal, once extremely popular, today is not done on a routine basis, but only where there is strict need. Mere enlargement of tonsils is no reason for removal. Tonsils are normally larger in children than in adults. Only when they interfere with breathing and swallowing may it be necessary to remove them because of size.

 Enlarged adenoids may block the openings of the Eustachian tubes and interfere with normal pressure changes in the middle ears, causing dis- comfort and hearing impairment. When enlarged adenoids happen to block the internal nares, they force mouth breathing. Fortunately, adenoid removal, when necessary, is a simple operation.

THE LARYNX 

The larynx, or voice box, is at the top of the windpipe, or trachea, which takes air to the lungs. But while incoming air passes through the boxlike larynx, it is actually air expelled from the lungs that makes voice sounds. In the front of the larynx, two folds of membranes, the vocal cords, areattached and held by tiny cartilages. Muscles attached to the cartilages move the vocal cords, which are made to vibrate by air exhaled from the lungs. 

The vibrations are carried through the air upward into the pharynx, mouth, nasal cavities, and sinuses, which serve as resonating chambers. The greater the force and amount of air from the lungs, the louder the voice. Pitch differences result from variations in the tension on the cords.

The larger the larynx and the longer the cords, the deeper the voice

 The average man's vocal cords are about three fourths of an inch long. Shorter vocal cords give women higher-pitched voices.