Head and neck muscles (chewing, facial, and throat muscles)

Oblique part of cricothyroid

Musculus cricothyroideus, pars obliqua

Origin

Front of the arch of the cricoid cartilage

Insertion

Lower border and inferior horn of the thyroid cartilage

Function

Tenses and lengthens the vocal fold (together with the straight part), raising pitch during phonation

Innervation

External branch of the superior laryngeal nerve (branch of the vagus nerve, CN X)

Movement & chain

Tilts the thyroid cartilage forward relative to the cricoid, lengthening the vocal folds; the only intrinsic laryngeal muscle not innervated by the recurrent laryngeal nerve.

Palpation

Palpable in the cricothyroid space between cricoid and thyroid cartilages.

Clinical

Damage to the superior laryngeal nerve (e.g. during thyroid surgery) causes a tired, less powerful voice with a reduced range for high notes.

Segmental innervation

Vagus nerve (X), motor via the external branch of the superior laryngeal nerve.

In clinical practice

Tenses vocal cords for high pitch; innervated by external branch of superior laryngeal nerve; injury causes loss of high pitch and vocal fatigue.

Region in the model

Head and neck muscles (chewing, facial, and throat muscles)