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.
