gated and tightened and the pitch of the voice
Relaxers of the Vocal Folds
- The principle relaxers of these folds are the broad thyroarytenoid
- They arise from the posterior surface of the thyroid cartilage near the median plane and
insert into the anterolateral surfaces of the arytenoid cartilages.
- One band of its inferior deep fibres, called the vocalis muscle,
arises from the vocal ligament and passes to the vocal process of the arytenoid cartilages
- The thyroarytenoid muscles pull the arytenoid cartilages anteriorly, thereby slackening
the vocal ligaments.
- The vocalis muscles produce minute adjustments of the vocal
ligaments (e.g., as occurs during whispering). They also relax parts of the
vocal folds during phonation and singing.
Blood Supply of the
Larynx (p. 847)
- The superior and inferior laryngeal arteries supply the
- They are branches of the superior and inferior thyroid arteries respectively.
- The superior laryngeal
artery runs with the internal branch of the superior laryngeal nerve through
the thyrohyoid membrane, and then branches to supply the internal surface of the larynx.
- The inferior laryngeal
artery runs with the inferior laryngeal nerve and supplies the mucous membrane
and muscles of the inferior aspect of the larynx.
Innervation of the
Larynx (p. 848-9)
- The laryngeal nerves are derived from the vagus
nerve (CN X) through the superior laryngeal nerve and the
recurrent laryngeal nerve.
- All intrinsic muscles, except cricothyroid, are innervated by the recurrent
laryngeal nerve with fibres from the accessory nerve (CN XI). The external laryngeal nerve supplies the cricothyroid muscle.
- The supraglottic portion of the laryngeal
mucosa is supplied by the internal laryngeal nerve,
a branch of the superior laryngeal nerve.
- The infraglottic portion of the laryngeal mucosa is
supplied by the recurrent laryngeal nerve.
Drainage of the Larynx (p. 849)
- The lymph vessels superior to the vocal folds accompany
the superior laryngeal artery through the thyrohyoid membrane and drain into the superior deep cervical lymph nodes.
- The lymph vessels inferior to the vocal folds drain
into the inferior deep cervical lymph nodes
(supraclavicular nodes) through the prelaryngeal, pretracheal, and paratracheal lymph