Anatomy and Functions of the Larynx

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Questions and Answers

What is the primary function of the larynx?

Regulating air flow to the lungs

Production of vocal sounds (correct)

Facilitating gas exchange

Filtering airborne particles

At what vertebral level is the larynx located in an adult?

C3 – C6 (correct)

C1 – C2

C6 – C8

C7 – T1

What anatomical feature is commonly associated with the male larynx after puberty?

Growth of the angle of thyroid cartilage (correct)

Development of multiple vocal folds

Length of the vocal cords decrease

Increase in the size of the epiglottis

What is laryngitis primarily caused by?

Infection and inflammation of the larynx Signup and view all the answers

Which condition may result from compressive pathologies affecting the trachea?

Dyspnoea and irritative cough Signup and view all the answers

What is the purpose of a tracheostomy?

To secure the airway in cases of obstruction Signup and view all the answers

What structure does the larynx communicate with above it?

Laryngopharynx Signup and view all the answers

How does the larynx's size differ between males and females after puberty?

Males have a larger larynx Signup and view all the answers

What role does the larynx play during swallowing?

It assists in the closing of the airway Signup and view all the answers

Which structure is the largest laryngeal cartilage?

Thyroid Cartilage Signup and view all the answers

What type of cartilage primarily composes the thyroid cartilage?

Hyaline Cartilage Signup and view all the answers

Which cartilage is shaped like a signet ring?

Cricoid Cartilage Signup and view all the answers

The epiglottis is formed from which developmental structure?

Caudal Part of Hypobranchial Eminence Signup and view all the answers

At what angle do the laminae of the thyroid cartilage meet in males?

90° Signup and view all the answers

Which paired cartilage is NOT part of the larynx?

Cricoid Cartilage Signup and view all the answers

What muscle has an insertion point on the posterior borders of the thyroid cartilage?

Salpingopharyngeus Muscle Signup and view all the answers

The thyroid angle is measured at 120° for which demographic?

Females Signup and view all the answers

Which of the following muscles does not attach to the outer surface of the laminae of the thyroid cartilage?

Diaphragm Muscle Signup and view all the answers

What type of cartilage comprises the thyroid, cricoid, and basal part of arytenoid cartilages?

Hyaline cartilage Signup and view all the answers

Which joint allows for rotatory and gliding movements to adjust vocal cords?

Cricoarytenoid joint Signup and view all the answers

Which laryngeal cartilage is NOT paired?

Thyroid Cartilage Signup and view all the answers

What is the primary function of the thyrohyoid membrane?

Connects the hyoid bone to the thyroid cartilage Signup and view all the answers

Which of the following ligaments is thicken in the midline and forms the median thyrohyoid ligament?

Thyrohyoid membrane Signup and view all the answers

What type of cartilage is found in the apices of the arytenoid, corniculate, and cuneiform cartilages?

Elastic cartilage Signup and view all the answers

Which joint has no functional significance?

Arytenocorniculate joint Signup and view all the answers

Which of the following structures passes through the thyrohyoid membrane?

Internal laryngeal nerve Signup and view all the answers

Which membrane connects the cricoid cartilage with the first tracheal ring?

Cricotracheal ligament Signup and view all the answers

What is the composition of the cricothyroid joint?

Plane synovial joint permitting rotatory and gliding movements Signup and view all the answers

The corniculate cartilages are primarily associated with which part of the larynx?

Posterior part of the aryepiglottic fold Signup and view all the answers

What is the primary action of the cricothyroid muscle?

Tenses the vocal cords Signup and view all the answers

Which muscle is considered the only unpaired muscle among the intrinsic laryngeal muscles?

Transverse arytenoid Signup and view all the answers

What is the action of the posterior cricoarytenoid muscle?

Abducts the vocal cords Signup and view all the answers

Which muscle acts to relax the vocal cords?

Thyroarytenoid Signup and view all the answers

What is the insertion point for the lateral cricoarytenoid muscle?

Muscular process of arytenoid cartilage Signup and view all the answers

The action of the thyroepiglotticus muscle is primarily to:

Open the inlet of the larynx Signup and view all the answers

What is the function of the thyroepiglottic ligament?

Links the lower end of the epiglottis to the thyroid angle Signup and view all the answers

Which structure forms the anterior boundary of the laryngeal inlet?

Epiglottis Signup and view all the answers

What separates the vestibule from the ventricle of the larynx?

Vestibular folds Signup and view all the answers

Which muscle is categorized as an extrinsic muscle of the larynx?

Thyrohyoid Signup and view all the answers

What is the primary feature of the saccule of the larynx?

It contains mucous glands that lubricate the vocal cords. Signup and view all the answers

In which part of the laryngeal cavity does the rima glottidis occur?

Between the vocal folds Signup and view all the answers

Which ligament is known as the vocal ligament?

Cricothyroid ligament Signup and view all the answers

Which structure is NOT a part of the laryngeal cavity?

Trachea Signup and view all the answers

What kind of epithelium lines the rima glottidis?

Stratified squamous epithelium Signup and view all the answers

Which of the following describes the arrangement of the intrinsic muscles of the larynx?

They primarily control tension and position of vocal cords. Signup and view all the answers

Study Notes

Anatomy of the Larynx

The larynx is a specialized organ located in the anterior neck at the level of C3 to C6 vertebrae, providing a protective sphincter at the inlet of the air passage.
In children and females, the larynx is situated at a higher level, and its size is similar before puberty. However, after puberty, the male larynx grows rapidly, resulting in a larger size and a deeper voice.
The larynx is responsible for voice production, also known as the voice box or organ of phonation.
The upward and downward movements of the larynx facilitate swallowing.
It communicates with the laryngopharynx above and continues with the trachea below.

Functions of the Larynx

Phonation: Production of sound for speech
Protection: Preventing food and fluid from entering the trachea
Respiration: Air passage for breathing
Deglutition: Swallowing

Structure of the Larynx

The larynx is composed of three unpaired cartilages: thyroid, cricoid, and epiglottis, and three paired cartilages: arytenoid, corniculate, and cuneiform.
These cartilages are interconnected by membranes and ligaments and are regulated by muscles.
The larynx is lined with a mucous membrane.

Unpaired Cartilages

Thyroid Cartilage: The largest laryngeal cartilage, composed of hyaline cartilage. It forms an angle known as the Adam's apple, measuring 90 degrees in males and 120 degrees in females.
Cricoid Cartilage: Shaped like a signet ring, located below the thyroid cartilage at the level of C6 vertebra.
Epiglottis: A leaf-shaped cartilage responsible for covering the glottis during swallowing.

Paired Cartilages

Arytenoid Cartilages: Two small, pyramid-shaped cartilages that play a crucial role in vocal cord movement.
Corniculate Cartilages (of Santorini): Two tiny nodules that articulate with the apex of the arytenoid cartilage, located in the posterior part of the aryepiglottic fold.
Cuneiform Cartilages (of Wrisberg): Two rod-like cartilages that articulate with the corniculate cartilage, located in the posterior part of the aryepiglottic folds.

Laryngeal Joints

Cricothyroid Joint: Between the inferior cornu of the thyroid and the side of the cricoid cartilage. It permits rotatory and gliding movements.
Cricoarytenoid Joint: Between the base of the arytenoid cartilage and the lateral part of the upper border of the cricoid cartilage.
Arytenocorniculate Joint: Between the arytenoid and corniculate cartilages.

Laryngeal Ligaments and Membranes

Thyrohyoid Membrane: Extends from the upper border of the thyroid cartilage to the posterior surface of the hyoid bone above, forming a central thickening known as the median thyrohyoid ligament.
Quadrangular Membrane: Extends between the epiglottis and arytenoid cartilages. Its thickened lower margin forms the vestibular ligament.
Cricotracheal Ligament: Connects the cricoid cartilage to the first tracheal ring.
Thyroepiglottic Ligament: Connects the lower end of the epiglottis to the posterior surface of the thyroid angle.
Hyoepiglottic Ligament: Connects the posterior aspects of the hyoid to the upper end of the epiglottis.
Cricothyroid Ligament: From the thyroid cartilage to the cricoid cartilage in the midline, with an upper thickened border known as the vocal ligament.

Laryngeal Cavity

The laryngeal cavity extends from the inlet to the lower border of the cricoid cartilage.
Laryngeal Inlet Boundaries:
- Anterior: Epiglottis
- Posterior: Interarytenoid fold
- Lateral: Aryepiglottic fold
Laryngeal Cavity Divisions:
- Vestibule (Upper Part): Extends from the upper border of the epiglottis to the vestibular folds.
- Ventricle or Sinus of Larynx (Middle Part): The space between the vestibular and vocal folds.
- Infraglottic Compartment (Lower Part): Extends from the vocal folds to the lower border of the cricoid cartilage.

Vestibule

Contains the vestibular folds, which are thickened portions of the quadrangular membrane.
Rima Vestibuli: The opening between the vestibular folds.

Ventricle

Contains the vocal folds.
Saccule of the Larynx: A narrow diverticulum of the mucous membrane between the vestibular fold and the thyroid cartilage, connected to the sinus of the larynx.
Saccule contains mucous glands that lubricate the vocal cords.

Rima Glottidis

The opening between the vocal folds and the vocal processes of the arytenoid cartilages. It is devoid of submucosa.

Muscles of the Larynx

Extrinsic Muscles:
- Elevators (Suprahyoid): Digastric, thyrohyoid, stylohyoid, mylohyoid, and geniohyoid muscles.
- Depressors (Infrahyoid): Sternothyroid, sternohyoid, and omohyoid muscles.
Intrinsic Muscles:
- Cricothyroid: Tenses the vocal cords.
- Posterior Cricoarytenoid: Abducts (opens) the vocal cords.
- Lateral Cricoarytenoid: Adducts (closes) the vocal cords.
- Transverse Arytenoid: Closes the posterior part of the rima glottidis.
- Oblique Arytenoid: Closes the rima glottidis.
- Thyroarytenoid: Relaxes the vocal cords.
- Vocalis: Relaxes the vocal cords.
- Aryepiglotticus: Closes the laryngeal inlet.
- Thyroepiglotticus: Widens the laryngeal inlet.

Clinical Correlations

Laryngoscopy: Examination of the larynx.
Laryngitis: Inflammation and infection of the larynx.
Tracheostomy: An emergency surgical procedure that involves creating an opening in the trachea to secure an airway.

Trachea

The trachea is normally median in position and can be palpated in the suprasternal notch.
It can be compressed by pathological enlargements of the thyroid, thymus, lymph nodes, and aortic arch, causing dyspnea, irritative cough, and hoarseness.

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Description

This quiz explores the anatomy, structure, and functions of the larynx, which plays a critical role in voice production, protection during swallowing, and respiration. It highlights significant anatomical details, including variations between children and adults. Test your understanding of this essential organ in the human body!