Anatomy of Larynx and Vocal Cords Quiz

Location and Function of the Larynx

• The larynx, or voice box, is located in the anterior neck at the level of the C3-6 vertebral bodies.
• It connects the oropharynx to the trachea and has several functions.

Structure of the Larynx

• The larynx is divided into three sections: supraglottis, glottis, and infraglottis.
• The glottis is the narrow area at the level of the vocal cords and divides the supraglottis and infraglottis.
• The larynx has a framework of cartilages, membranes, and ligaments lined by respiratory mucosa.
• The laryngeal skeleton consists of 9 cartilages: 3 single and 3 paired.
• The 3 unpaired cartilages are: epiglottis, cricoid, and thyroid cartilages.
• The 3 paired cartilages are: arytenoid, corniculate, and cuneiform cartilages.

Cartilages and Membranes

• The cartilages are connected by numerous membranes and ligaments to unite the larynx as a single structure.
• Three membranes connect the unpaired cartilages of the larynx to each other and to other nearby structures.
• The quadrangular membrane spans between the epiglottis and arytenoid cartilages.

Laryngeal Muscles

• The larynx has two groups of muscles: extrinsic and intrinsic.
• Extrinsic muscles attach the larynx to other structures and act to move the entire larynx.
• Intrinsic muscles are found within the larynx itself and act primarily on the vocal cords.
• Extrinsic muscles include: sternothyreoideus, sternohyoideus, and thyrohyoideus.
• Intrinsic muscles include: lateral cricoarytenoid, transverse arytenoid, and cricothyroid.

Actions of the Larynx

• The larynx executes different movements depending on the action being performed.
• During swallowing, the larynx has several protective mechanisms to prevent food/drink from entering the airway.

Nerve Supply of the Larynx

• The larynx is innervated by branches of the vagus nerve (CN X).
• The branches are the superior laryngeal nerve and the recurrent laryngeal nerve.
• The recurrent laryngeal nerve has an important path, branching distally from the vagus nerve and then travelling back on itself towards the larynx.
• The supraglottis is supplied by the internal branch of the superior laryngeal nerve, while the infraglottis is supplied by the recurrent laryngeal nerve.
• The innervation of the glottis is somewhat disputed, but many accept that it is innervated by the recurrent laryngeal nerve.