Lateral Cricoarytenoid

Origin, Insertion, Action & Nerve

Attachments explained

The Lateral Cricoarytenoid is defined first by where it attaches. Its origin is the more fixed anchor, usually the proximal or more stable end that stays put during contraction, while its insertion is the more mobile point that is pulled toward the origin when the muscle shortens.

Action & function

When the Lateral Cricoarytenoid contracts, it produces the following movement: Adducts the vocal folds, closing the rima glottidis.

As part of the Larynx group of the Head & Neck, it works alongside neighbouring muscles to generate smooth, coordinated movement and to stabilise the structures it acts on.

Nerve supply & clinical relevance

The Lateral Cricoarytenoid receives its nerve supply from the Recurrent laryngeal nerve (vagus, CN X).

Because a muscle can only contract when its nerve is intact, injury to the Recurrent laryngeal nerve can weaken or paralyse the Lateral Cricoarytenoid, impairing the movements it normally produces (adducts the vocal folds, closing the rima glottidis). This is why knowing the innervation is central to localising nerve lesions in clinical practice.

How to study the Lateral Cricoarytenoid (the OIANS method)

Learn the lateral cricoarytenoid as the mirror image of the posterior one: both grip the muscular process of the arytenoid, but the lateral fibres pull it forward, rotating the vocal process inward to close the front of the glottis. Reading the two together as forward-closes versus backward-opens makes their opposite actions inseparable.

Divide glottic closure between the two adductors to keep them distinct: the lateral cricoarytenoid shuts the anterior intermembranous part, while the transverse arytenoid seals the posterior intercartilaginous part. All of these share the recurrent laryngeal nerve, so grouping the closers by which region of the rima they cover is the reliable way to remember them.

Frequently asked questions

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