The oblique arytenoid, the more superficial Arytenoid muscle

Arytenoid muscle

The arytenoid is a single muscle, filling up the posterior concave surfaces of the arytenoid cartilages.It arises from the posterior surface and lateral border of one arytenoid cartilage, and is inserted into the corresponding parts of the opposite cartilage.It consists of oblique and transverse...

, forms two fasciculi

Muscle fascicle

In anatomy, a fascicle is a bundle of skeletal muscle fibers surrounded by perimysium, a type of connective tissue.Specialized muscle fibers in the heart that transmit electrical impulses from the Atrioventricular Node to the Purkinje Fibers are fascicles, also referred to as bundle branches...

, which pass from the base of one cartilage to the apex of the opposite one, and therefore cross each other like the limbs of the letter X; a few fibers are continued around the lateral margin of the cartilage, and are prolonged into the aryepiglottic fold; they are sometimes described as a separate muscle, the Aryepiglotticus.

The aryepiglottic muscle together with the transverse arytenoid and the thyroarytenoid work as a sphincter

Sphincter

A sphincter is an anatomical structure, or a circular muscle, that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning...

 and close the larynx

Larynx

The larynx , commonly called the voice box, is an organ in the neck of amphibians, reptiles and mammals involved in breathing, sound production, and protecting the trachea against food aspiration. It manipulates pitch and volume...

as we swallow or cough. Its innervation is by the recurrent laryngeal nerve (from vagus) just like all the intrinsic muscles of the larynx except the cricothyroid muscle.

External links