larynx

What is the larynx?

The larynx is the connection between the pharynx and the trachea.

What are the functions of the larynx?

Prevents foreign bodies from entering the airways, produces sound (phonation), and is mobile during swallowing.

Where is the larynx located?

In the midline, opposite the 3rd to the 6th cervical vertebrae (C3 to C6).

How does the size of the larynx differ among individuals?

It is shorter in women and children, similar in size in prepubescent males and females, and enlarges significantly in males after puberty.

How many cartilages form the larynx?

The larynx is formed by 9 cartilages: 3 paired and 3 unpaired.

What is the vallecula?

A depression in the mucosa between the pharyngeal portion of the tongue and the anterior border of the epiglottis.

What type of epithelium primarily lines the larynx?

Primarily pseudostratified columnar with cilia, except in certain regions.

What areas of the larynx have stratified squamous non-keratinized epithelium?

Anterior surface along the epiglottis and true vocal cords.

What are the regions of the larynx?

Vestibule (supraglottic), Ventricle, and Infraglottic (subglottic).

What are the anatomical relations of the larynx?

Anterolateral: Infrahyoid muscles, platysma; Lateral: Lobes of the thyroid gland, carotid sheath; Posterior: Anterior wall of the laryngopharynx; Superior: Base of tongue and vallecula; Inferior: Trachea.

What is the largest laryngeal cartilage?

Thyroid cartilage.

What type of cartilage is the thyroid cartilage?

Hyaline cartilage.

Is the thyroid cartilage paired or unpaired?

Unpaired.

How does the thyroid cartilage connect to the hyoid bone?

Via the thyrohyoid membrane.

At which vertebral levels does the thyroid cartilage lie?

C4 to C6.

What is the only complete ring of cartilage in the respiratory system?

Cricoid cartilage.

What shape is the cricoid cartilage?

Signet-shaped.

What type of muscles attach to the cricoid cartilage?

Both intrinsic and extrinsic laryngeal muscles.

At which vertebral level does the cricoid cartilage lie?

C6.

What type of cartilage makes up the arytenoid cartilage?

Hyaline (majority) and elastic (apex and small portion of vocal process).

Is the arytenoid cartilage paired or unpaired?

Paired.

What structure does the arytenoid cartilage help form?

Framework of the true vocal cords.

What type of cartilage is the epiglottis?

Elastic cartilage.

Is the epiglottis paired or unpaired?

Unpaired.

What is the function of the epiglottis?

Helps prevent foreign bodies from entering the larynx.

Are the corniculate cartilages paired or unpaired?

Paired.

Where are the corniculate cartilages located?

In the aryepiglottic fold.

Are the cuneiform cartilages paired or unpaired?

Paired.

What are the 2 lateral laminae of the larynx?

Two plates that meet at an acute angle in the anterior midline.

What is another name for the laryngeal prominence?

Adam’s apple.

How is the laryngeal prominence formed?

By the fusion of the 2 lateral laminae.

How does the laryngeal prominence angle differ between males and females?

Males: 90-degree angle; Females: 120-degree angle.

Is the laryngeal prominence larger in males or females?

Larger in males.

What is the thyroid notch?

The superior portion of the laryngeal prominence, forming a V shape.

Where is the superior tubercle located?

At the superior border of the oblique line.

What is the function of the oblique line?

Serves as an attachment for the extrinsic muscles of the larynx.

Where is the inferior tubercle located?

At the inferior border of the oblique line.

What is the function of the superior horn of the thyroid cartilage?

Provides the lateralmost attachment for the thyrohyoid membrane.

What is the function of the inferior horn of the thyroid cartilage?

Articulates with the cricoid cartilage to form the cricothyroid joint.

What is the height of the cricoid cartilage arch (anteriorly)?

6 mm.

Which muscle attaches to the arch of the cricoid cartilage?

Cricothyroid muscle.

Which muscle attaches posterior to the cricothyroid muscle on the cricoid arch?

Inferior portion of the inferior constrictor muscle (cricopharyngeus).

What is the height of the cricoid cartilage lamina (posteriorly)?

2 to 3 cm.

Which muscle attaches to the lamina of the cricoid cartilage?

Posterior cricoarytenoid muscle.

What does the superior border of the lamina articulate with?

Arytenoid cartilage.

What does the inferior border of the lamina articulate with?

Inferior cornu of the thyroid cartilage.

How many arytenoid cartilages are there?

Paired (two total).

What are the three surfaces of each arytenoid cartilage?

Anterolateral, Posterior, and Medial.

What are the two main parts of the arytenoid cartilage?

Apex and Base.

What is the apex of the arytenoid cartilage?

The superior extension of the arytenoid cartilage.

Which cartilage articulates with the apex of the arytenoid cartilage?

Corniculate cartilage.

What type of cartilage is the apex composed of?

Elastic cartilage.

What is the base of the arytenoid cartilage?

The larger, broad surface that articulates with the cricoid cartilage.

What are the two processes of the base of the arytenoid cartilage?

Muscular process and Vocal process.

What type of cartilage is the base composed of?

Hyaline cartilage, except for a small portion of the vocal process.

What joint is formed by the articulation between the base of the arytenoid cartilage and the cricoid cartilage?

Cricoarytenoid joint.

What is a potential complication involving the arytenoid cartilage?

The arytenoid cartilage can dislocate.

What is the shape of the epiglottic tubercle?

Pear-shaped.

How is the epiglottis connected to the thyroid cartilage?

By the thyroepiglottic ligament.

How is the epiglottis connected to the hyoid bone?

By the hyoepiglottic ligament.

What happens to the epiglottis during deglutition (swallowing)?

It moves posteriorly, diverting food and liquid from the laryngeal inlet.

What type of epithelium covers the anterior surface of the epiglottis?

Stratified squamous nonkeratinized epithelium.

What type of epithelium covers the posterior surface of the epiglottis?

Pseudostratified columnar epithelium with cilia.

Where is the corniculate cartilage located?

On the apex of the arytenoid cartilage.

What is the function of the corniculate cartilage?

It helps support the aryepiglottic fold.

Where is the cuneiform cartilage located?

Superior to the corniculate cartilage.

What is the function of the cuneiform cartilage?

It helps support the aryepiglottic fold.

Where is the triticeal cartilage located?

In the posterior border of the thyrohyoid membrane.

Where is the cricothyroid joint located?

Between the inferior cornu of the thyroid cartilage and the inferior border of the lamina of the cricoid cartilage.

What type of joint is the cricothyroid joint?

Synovial joint.

What movement does the cricothyroid joint allow?

Rotation between thyroid and cricoid cartilages.

Where is the cricoarytenoid joint located?

Between the superior border of the lamina of the cricoid cartilage and the base of the arytenoid cartilage.

What type of joint is the cricoarytenoid joint?

Synovial joint.

What are the two movements that occur in the cricoarytenoid joint?

Rotation and Gliding.

What happens when medial rotation and medial gliding occur in the cricoarytenoid joint?

It closes the rima glottidis.

What happens when lateral rotation and lateral gliding occur in the cricoarytenoid joint?

It opens the rima glottidis.

Where does the thyrohyoid membrane extend from?

From the thyroid cartilage to the hyoid bone.

What does the thyrohyoid membrane allow passage of?

The internal laryngeal nerve, superior laryngeal artery, and superior laryngeal vein.

Where does the thyroepiglottic ligament extend from?

From the thyroid cartilage to the epiglottis.

What is the function of the thyroepiglottic ligament?

It holds the epiglottis to the thyroid cartilage.

Where does the hyoepiglottic ligament extend from?

From the hyoid bone to the epiglottis.

What is the function of the hyoepiglottic ligament?

It holds the epiglottis to the hyoid bone.

Where does the cricotracheal ligament extend from?

From the cricoid cartilage to the trachea.

What is the function of the cricotracheal ligament?

It attaches the cricoid cartilage to the first tracheal ring.

Can the cricotracheal ligament be used for anything in an emergency?

Yes, in establishing an emergency airway.

Where does the vocal ligament extend from?

From the arytenoid (vocal process) to the thyroid cartilage.

What does the vocal ligament help form?

The true vocal cord.

What is another name for the conus elasticus?

Cricovocal membrane.

Where does the lateral part of the conus elasticus extend?

Superiorly to thyroid, vocal ligament, arytenoid; Inferiorly to upper border of cricoid.

What does the lateral part of the conus elasticus help form?

The true vocal cord.

Where does the medial part of the conus elasticus extend from?

From the cricoid cartilage to the thyroid cartilage.

What is the primary site for establishing an emergency airway?

The medial part of the conus elasticus.

Where does the quadrangular membrane extend from?

From the arytenoid to the epiglottis.

What does the quadrangular membrane help form?

The false vocal cord.

Where is the vestibular ligament located?

On the free edge of the inferior border of the quadrangular membrane.

Where does the cricothyroid muscle originate from?

The arch of the cricoid.

Where does the cricothyroid muscle insert?

The lamina and inferior cornu of the thyroid.

What is the action of the cricothyroid muscle?

It increases (lengthens) tension on the vocal ligaments.

What is the nerve supply for the cricothyroid muscle?

The external laryngeal nerve.

Where does the thyroarytenoid muscle originate from?

The angle of the thyroid cartilage.