Chapter 19 - Larynx (BOOK)

The larynx is a ________ organ

Cartilaginous

Where is the larynx located?

At the superior end of the trachea

What are the functions of the larynx?

1. As a valve to guard the air passages, especially during swallowing food.

2. In maintaining an open air passage

3. vocalization

How many major types of cartilages make up the larynx?

4

What are the types of cartilages comprising the larynx

TIMES COMES AND ENDS 1. Thyroid cartilage

2. Cricoid cartilage

3. Arytenoid cartilages

4. Epiglottic cartilage

What is the largest cartilage of the trachea?

Thyroid cartilage

What is the thyroid cartilage composed of, and how do they fuse?

Two flat planes termed laminae, which fuse anteriorly and diverge posteriorly

Where the laminae of the thyroid cartilage fuse anteriorly, they form the...

Laryngeal prominence (Adam's apple)

The superior border of the thyroid cartilage forms the palpable:

Superior thyroid notch

The superior horn of the thyroid cartilage attaches via what to what?

Via ligaments to the hyoid bone

The inferior horn of the thyroid cartilage articulates with what?

The cricoid cartilage

The lateral surface of the thyroid cartilage is crossed by what?

An oblique line to which the strap muscles of the neck attach

What is the cricoid cartilage?

A complete ring of cartilage that forms a shape similar to a ring

What is the posterior part of the cricoid cartilage in the form of?

A flat plate, the lamina

What is the anterior narrow part of the cricoid cartilage called?

The arch

Where does the arch of the cricoid cartilage lie at?

The level of CV6

The upper border of the cricoid cartilage articulates with what?

The arytenoid cartilages

What is the lower border of the cricoid cartilage connected to and via the what?

The first ring of the trachea via the cricotracheal ligament

What are the arytenoid cartilages?

A pair of cartilages located at the upper border of the lamina of the cricoid cartilage

What is the shape of the arytenoid cartilages?

Pyramidal, with an apex above and a base below

The base of the arytenoid cartilage exhibits what two processes?

Vocal and muscular process

What is the vocal process of the arytenoid cartilage?

A process that extends forward from the base and serves as attachment for the vocal ligament

What is the muscular process of the arytenoid cartilage?

A process that extends laterally and serves as an attachment for the muscles of the larynx

What is the epiglottic cartilage?

A leaf shaped cartilage that extends superiorly and posteriorly from the thyroid cartilage

The upper end of the epiglottic cartilage is quite _____, whereas its lower end narrows, forming the _________ that attaches to the thyroid cartilages

Broad, narrows, stalk (petiolus)

What does the epiglottic cartilage function in?

Closing the opening into the laryngeal cavity during swallowing

There are two smaller types of cartilages, what are they?

corniculate and cuneiform cartilages

What does the corniculate cartilages sit upon?

The apices of the arytenoid cartilages

Where are the cuneiform cartilages located?

Within the fold of mucous membrane between the arytenoid and the epiglottic cartilages, known as the aryepiglottic folds

What is the extrinsic elevators of the larynx?

(Elevate) THE DOGS MOUTH SLOWLY Thyrohyoid, stylohyoid, mylohyoid, digastric

What are the extrinsic depressors of the larynx?

(Depress) studying on Sunday Omohyoid, sternohyoid, and strenothyroid

What are the intrinsic muscles of the larynx?

(Internally) the voice pits are looking cool

-Cricothyroid

-posterior cricoarytenoid

-lateral cricoarytenoid

-arytenoideus

-thyroarytenoid

-vocalis

What does the cricothyroid extend from?

The arch of the cricoid to the lamina of the thyroid and inferior horn of the thyroid cartilage

What does the posterior cricoarytenoid extend from?

The posterior surface of the lamina of the cricoid to the muscular process of the arytenoid

What does the lateral cricoarytenoid course from?

The arch of the cricoid to the muscular process of the arytenoid

What does the arytenoideus connect?

The posterior surfaces of the two arytenoids

What does the thyroarytenoid extend from?

The medial surface of the lamina of the thyroid cartilage to the muscular process of the arytenoid

What does the vocalis course from?

The internal surface of the thyroid cartilage posteriorly to the vocal process of the arytenoid cartilage

What is the action of all intrinsic muscles of the larynx?

All intrinsic muscles are adductors of the vocal folds with the exception of the posterior cricoarytenoid, which is an abductor

What is the innervation of all intrinsic muscles of the larynx?

All intrinsic muscles of the larynx are supplied by the recurrent laryngeal nerve, with the exception of the cricothyroid, which is supplied by the superior laryngeal nerve

The superior laryngeal nerve is a direct branch of what nerve?

Vagus nerve

What nerve branches into two branches that supply the larynx?

The superior laryngeal nerve

The external branch of the superior laryngeal nerve courses on what surface of the larynx?

External surface

What does the external branch of the superior laryngeal nerve innervate?

The cricothyroid muscle

The internal branch of the superior laryngeal nerve pierces what?

The membrane between the hyoid bone and the thyroid cartilage, which is known as the thyrohyoid membrane

What does the internal branch of the superior laryngeal nerve supply?

Sensory innervation to the mucous membrane lining the larynx above the vocal folds

What is the name of the nerve that is a direct branch of the vagus nerve that begins in the thorax?

Recurrent larygneal nerve

The right recurrent laryngeal nerve loops around what?

The subclavian artery

What does the left recurrent laryngeal nerve loop around?

The aorta

Both the right and left recurrent laryngeal nerves ascend to what?

The larynx in the groove between the esophagus and the trachea

The recurrent laryngeal nerve supplies what?

Sensory innervation to the mucous membrane below the vocal folds, along with the majority of the intrinsic muscles of the larynx

Arterial supply to the larynx comes from what primary vessels?

Superior laryngeal artery and inferior laryngeal artery

What does the superior laryngeal artery arise from?

arises from the superior thyroid artery from the external carotid artery

What does the inferior laryngeal artery arise from?

arises from the inferior thyroid artery from the thyrocervical trunk, which arises from the subclavian artery

How is the cavity of the larynx divided?

Divided into 3 portions:

-Vestibule

-Ventricle, and

-Infraglottic cavity

How are the portions of the cavity of the larynx separated?

By two horizontal folds of mucous membrane: false vocal fold and true vocal fold

The vestibule of the larynx extends from what?

The aditus or inlet down to the false vocal folds, also known as the vestibular folds

What is the aditus/inlet?

The opening into the larynx from the laryngopharynx

What is the aditus bounded by?

The epiglottis anteriorly and on each side by the aryepiglottic folds

What does closure of the inlet by the epiglottis protect?

The respiratory passages against the invasion of food and foreign bodies

Where do the false vocal folds extend from

The thyroid cartilage in front to the arytenoid cartilages behind

What does each false fold contain?

The vestibular ligament

Since the false vocal folds are not involved in voice production, they are referred to as the:

False vocal folds

The space between the two false folds of either side is called the:

Rima vestibuli

The muscles that also adduct the true vocal folds also adduct the _________, obliterating the __________

false vocal folds, obliterating the rima vestibuli

The obliteration of the rima vestibuli when the vestibular folds are adducted allows for what?

An increase in intrathoracic pressure or intraabdominal pressure during urination, defecation, or parturition

What is the ventricle (of Morgagni) ?

The space located on either side of the larynx between the false vocal fold above and the true vocal fold below

What does the ventricle of Morgagni function in?

Allowing free movement of the vocal folds

Where do the true vocal folds bound the ventricle?

Inferiorly

What are the true vocal folds and what do they contain?

Two folds of mucous membrane that contain the vocalis muscle and the vocal ligament

Where do the true vocal folds extend from?

The angle of the thyroid cartilage in front to the vocal processes of the arytenoids cartilages behind

What is the space that lies between the two true vocal folds called?

The rima glottidis

What represents the narrowest part of the laryngeal cavity?

Rima glottidis

What does the true vocal folds control?

The stream of air passing through the rima glottidis, making them important in voice production

What does the one median glossoepiglottic fold attach the epiglottis to?

The posterior tongue

What does the two lateral glossoepiglottic folds attach the epiglottis to?

The pharynx

Between the median and lateral glossoepiglottic folds, what is found?

Depressions called epiglottic valleculae, in which saliva collects from the posterior tongue

Valleculae are important landmarks during what?

Intubation