Thyroid cartilage: the Adam's apple, laminae, horns and vocal folds

Where is the thyroid cartilage?

Put a finger on your Adam's apple and swallow. Do you feel something firm rise and drop back? That is the thyroid cartilage.

It is the largest cartilage of the larynx, in the middle of the front of the neck at about the level of C4–C5, with the hyoid bone above and the cricoid cartilage below. It moves when you swallow because the whole larynx rises with the hyoid.

Two laminae and the laryngeal prominence

The cartilage is made of two four-sided plates, the laminae, joined in front and open behind, a V shape from above. The upper part of the angle juts forward as the laryngeal prominence, the Adam's apple, with the V-shaped superior thyroid notch just above it. The angle is smaller and sharper in males and wider in females, which is why the prominence is usually more visible in men; textbooks give slightly different figures, and individuals vary.

Horns and connections

The upper border is joined to the hyoid by the thyrohyoid membrane, from which the larynx hangs, and the lower border to the cricoid by the cricothyroid ligament. The oblique line on the outer surface of each lamina gives attachment to the sternothyroid and thyrohyoid and origin to the inferior pharyngeal constrictor.

The vocal folds inside

The front ends of the vocal ligaments attach inside the angle; their back ends attach to the arytenoid cartilages. To raise pitch, the cricothyroid tilts the thyroid cartilage forward at the cricothyroid joint, stretching the vocal folds.

Name and terms

Thyroid comes from the Greek thyreos, shield. The thyroid gland was named after this cartilage. Related terms: laryngeal prominence (Adam's apple), superior thyroid notch, superior and inferior horns. The Latin is cartilago thyroidea.

See it in the app

From the front the cartilage looks like a simple shield, but from the side and back the open V and the horns appear. In the 3D anatomy app teamLabBody you can keep only the laryngeal cartilages and rotate them to follow the superior horns to the hyoid and the inferior horns to the cricoid, then add the epiglottis and arytenoids to see the whole larynx. Cross sections are available with the PREMIUM plan.

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