Page 878 - Fundamentals of anatomy physiology

Chapter 23 The Respiratory System 865

Figure 23–5 The Glottis and Surrounding Structures.

Corniculate POSTERIOR Corniculate cartilage
cartilage Cuneiform cartilage
Aryepiglottic
Cuneiform fold Glottis (open)
cartilage
Rima glottidis
Vestibular Vocal fold
fold
Vestibular fold
Vocal fold Vocal nodule
of glottis
Epiglottis Epiglottis
Root of tongue
ANTERIOR c Photograph taken with a laryngoscope
a Glottis in the closed position. b Glottis in the open position. positioned within the oropharynx,
superior to the larynx. Note the
abnormal vocal nodule.

&T i p s T r i c k s into the larynx. While this movement is under way, the glottis
Intelligible sound requires both phonation and articulation. is closed.
Saying “ahhhh” while your tongue is depressed during a tonsil
examination is an example of phonation. Saying “hot” adds Food or liquids that touch the vestibular folds or glottis trig-
articulation to that sound. ger the coughing reflex. In a cough, the glottis is kept closed while
the chest and abdominal muscles contract, compressing the
The final production of distinct words depends further lungs. When the glottis is opened suddenly, a blast of air from
on voluntary movements of your tongue, lips, and cheeks. An the trachea ejects material that blocks the entrance to the glottis.
infection or inflammation of the larynx is known as laryngitis
(lar-in-JI.-tis). It commonly affects the vibrational qualities of Checkpoint
the vocal folds. Hoarseness is the most familiar result. Mild
cases are temporary and seldom serious. However, bacterial 7. Identify the paired and unpaired cartilages associated
or viral infections of the epiglottis can be very dangerous. The with the larynx.
resulting swelling may close the glottis and cause suffocation.
This condition, acute epiglottitis (ep-i-glot-TI.-tis), can develop 8. What are the highly elastic vocal folds of the glottis
rapidly after a bacterial infection of the throat. Young children better known as?
are most likely to be affected.
9. When the tension in your vocal folds increases, what
The Laryngeal Musculature happens to the pitch of your voice?

The larynx is associated with two sets of muscles. They in- See the blue Answers tab at the back of the book.
clude (1) muscles of the neck and pharynx, which position
and stabilize the larynx ( pp. 374–376), and (2) smaller 23-4 The trachea and primary 23
intrinsic muscles that control tension in the glottal vocal folds
or open and close the glottis. These smaller muscles insert on bronchi convey air to and from the lungs
the thyroid, arytenoid, and corniculate cartilages. The opening
or closing of the glottis involves rotational movements of the Learning Outcome Discuss the structures of the extrapulmonary
arytenoid cartilages. airways.

When you swallow, both sets of muscles work together Three large, extrapulmonary airways are associated with the
to prevent food or drink from entering the glottis. Food is lungs: the trachea and the right and left primary bronchi.
crushed and chewed into a pasty mass, known as a bolus, be-
fore being swallowed. Muscles of the neck and pharynx then The Trachea
elevate the larynx, bending the epiglottis over the glottis, so
that the bolus can glide across the epiglottis rather than falling The trachea (TRA. -ke. -uh), or windpipe, is a tough, flexible tube
with a diameter of about 2.5 cm (1 in.) and a length of about
11 cm (4.33 in.) (Figure 23–6). The trachea begins anterior to
vertebra C6 in a ligamentous attachment to the cricoid cartilage.
It ends in the mediastinum, at the level of vertebra T5, where it
branches to form the right and left primary bronchi.