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By

Dr. Musaed Al Fayez

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Specialized organ at theinlet of air passage.

Function:

1- Protective sphincterat the air passage.

2- Phonation. 3- Regulates passage of

air in inspiration andexpiration.

4- Opens & closesduring swallowing,coughing & sneezing.

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Unpaired cartilages

Epiglottis

Thyroid cartilage

Cricoid

Paired cartilages

Arytenoid

Corniculate

Cuneiform

All cartilages arehyaline except the

epiglottis (elastic)

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The framework of the larynx is made up of cartilages.

These cartilages are connected by joints, membranes& ligaments.

Moved by muscles.

Lined by mucous membranes.

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The Laryngealcartilage are Nine

3 single & 3 Paired Single:

Thyroid

Cricoid Epiglottis.

Paired:

Arytenoids

Corniculate

Cuneiform.

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Thyroid Cartilage

It is the largest of the

laryngeal cartilage. Formed of 2 laminae,

each has superior &

inferior horn. The angle between 2

laminae is 90 in male

& 120 in female. It has 2 notches superior

& inferior at the meetingof its 2 laminae.

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Connection of thethyroid cartilage:

Superior: To hyoidbone bythyrohyoid

membrane. Inferior: To cricoid

cartilage by the

cricothyroid joint& cricothyroidmembrane

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Epiglottis:

Leaf-shaped elasticcartilage.

Lies behind the root of thetongue.

Connected by its stalk to theback of the thyroidcartilage.

Its sides are connected tothe arytenoid cartilage byaryepiglottic fold.

Its upper end is free. But its

mucous membrane isconnected to the back oftongue by 3 glossoepiglotticfolds one median & 2lateral.

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Cricoid cartilage: Hyaline.

Ring shaped, having a narrow anterior arch and wide posteriorlamina.

Connected superiorly to thyroid cartilage by cricothyroid joint andcricothyroid membrane.

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Arytenoid cartilage: Paired hyaline cartilage.

Shaped like a 3- sided pyramid.

Its base sits on the superiorsurface of the cricoid lamina.

Apex: directed superiorly,supports the corniculate

cartilage. Muscular process directed

laterally, gives attachment to 3muscles:

Posterior & lateral

cricoarytenoid. And Thyroarytenoid.

Vocal process: directed forwardand gives attachment to the

vocal ligament.

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2 Major groups

Extrinsic Muscles: ( move the whole larynx)

Elevators: Digastric, stylohyoid, mylohyoid,geniohyoid, stylopharyngeus,

salpingopharyngeus & palatopharyngeus. Depressors: Sternothyroid, sternohyoid &

omohyoid.

Intrinsic Muscles ( movement within larynx) Control of laryngeal inlet

Control of rima glottidis

Control of length & tension of vocal cords All intrinsic muscles lie inside the larynx cricothyroid

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Origin: Anterior part of arch of cricoid

Insertion: Inferior border & inf. Horn of thyroid Causes flexion at cricothyroid joint

Lengthens & tightens the vocal ligament

Nerve supply: External laryngeal nerve of superior

laryngeal of vagus.

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Posterior cricoarytenoid is the onlyabductor of the vocal cords.

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Posteriorcricoarytenoids

Lateral cricoarytenoid

Interarytenoidmuscles:

Transverse &

Oblique

Thyroarytenoidmuscle

Aryepiglottic muscles

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MOTORAll muscles of the larynx are supplied the

recurrent laryngeal nerve EXCEPT

Cricothyroid

supplied by external laryngealbranch of superior laryngeal nerve.

SENSORY & SECRETOMOTOR

Above Vocal Cords: Internal laryngeal Below Vocal Cords: Recurrent laryngeal

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The interior of the larynx

It is divided into 3 parts:

1- vestibule: betweenlaryngeal inlet & vestibularfold.

2- Ventricle: a depressionextending laterallybetween vestibular & vocalfolds.

3- Infraglottic cavity: liesbetween the vocal fold &

lower border of cricoidcartilage.

It is continuous with thetrachea inferiorly.

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Superior laryngeal artery branch ofsuperior thyroid artery

Inferior laryngeal artery

branch ofinferior thyroid artery

Veinsaccompany the arteries