Chapter 22
The Respiratory System
807
22
The Larynx
Basic Anatomy
Te
larynx
(lar
9
ingks), or voice box, extends for about 5 cm
(2 inches) from the level of the third to the sixth cervical ver-
tebra. Superiorly it attaches to the hyoid bone and opens into
the laryngopharynx. Inferiorly it is continuous with the trachea
(Figure 22.3b).
Te larynx has three functions. Its two main tasks are to pro-
vide a
patent
(open) airway and to act as a switching mecha-
nism to route air and food into the proper channels. Because the
larynx houses the vocal folds (vocal cords), its third function is
voice production.
Te framework of the larynx is an intricate arrangement
of nine cartilages connected by membranes and ligaments
(Figure 22.4)
. Except for the epiglottis, all laryngeal cartilages
are hyaline cartilages.
Te large, shield-shaped
thyroid cartilage
is formed by the
fusion of two cartilage plates. Te midline
laryngeal promi-
nence
(lah-rin
9
je-al), which marks the fusion point, is obvious
externally as the
Adam’s apple
. Te thyroid cartilage is typically
Body of hyoid bone
Epiglottis
Body of hyoid bone
Thyrohyoid membrane
Vestibular fold
(false vocal cord)
Vocal fold
(true vocal cord)
Cricothyroid ligament
Cricotracheal ligament
Fatty pad
Thyroid cartilage
Cuneiform cartilage
Corniculate cartilage
Arytenoid cartilage
Cricoid cartilage
Tracheal cartilages
Arytenoid muscles
Thyroid cartilage
Laryngeal prominence
(Adam’s apple)
Cricothyroid ligament
Cricotracheal ligament
(a) Anterior superficial view
(b) Sagittal view; anterior surface to the right
Thyrohyoid
membrane
Epiglottis
Hyoid bone
Lateral
thyrohyoid
membrane
Arytenoid
cartilage
Glottis
Thyroid
cartilage
Corniculate
cartilage
Cricoid
cartilage
Tracheal
cartilages
(c) Photograph of cartilaginous framework of
the larynx, posterior view
(d) Photograph of posterior aspect
Epiglottis
Laryngeal
inlet
Corniculate
cartilage
Posterior
cricoarytenoid
muscle on
cricoid
cartilage
Trachea
Figure 22.4
The larynx.
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