By
Dr. Musaed Al Fayez
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Specialized organ at the
inlet of air passage.
 Function:
1- Protective sphincter
at the air passage.
2- Phonation.
3- Regulates passage of
air in inspiration and
expiration.
4- Opens & closes
during swallowing,
coughing & sneezing.
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Unpaired cartilages
 Epiglottis
 Thyroid cartilage
 Cricoid
Paired cartilages
 Arytenoid
 Corniculate
 Cuneiform
 All cartilages are
hyaline 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 Laryngeal
cartilage 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 meeting
of its 2 laminae.
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Connection of the
thyroid cartilage:
Superior: To hyoid
bone by
thyrohyoid
membrane.
Inferior: To cricoid
cartilage by the
cricothyroid joint
& cricothyroid
membrane
Epiglottis:
Leaf-shaped elastic
cartilage.
Lies behind the root of the
tongue.
Connected by its stalk to the
back of the thyroid
cartilage.
Its sides are connected to
the arytenoid cartilage by
aryepiglottic fold.
Its upper end is free. But its
mucous membrane is
connected to the back of
tongue by 3 glossoepiglottic
folds one median & 2
lateral.
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Cricoid cartilage:
Hyaline.
Ring shaped, having a narrow anterior arch and wide posterior
lamina.
Connected superiorly to thyroid cartilage by cricothyroid joint and
cricothyroid membrane.
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Arytenoid cartilage:
Paired hyaline cartilage.
Shaped like a 3- sided pyramid.
Its base sits on the superior
surface of the cricoid lamina.
Apex: directed superiorly,
supports the corniculate
cartilage.
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Muscular process directed
laterally, gives attachment to 3
muscles:
Posterior & lateral
cricoarytenoid.
And Thyroarytenoid.
Vocal process: directed forward
and 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 only
abductor of the vocal cords.
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Posterior
cricoarytenoids
Lateral cricoarytenoid
Interarytenoid
muscles:
 Transverse &
 Oblique
Thyroarytenoid
muscle
Aryepiglottic muscles
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MOTOR
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All muscles of the larynx are supplied the
recurrent laryngeal nerve EXCEPT
Cricothyroid – supplied by external laryngeal
branch of superior laryngeal nerve.
SENSORY & SECRETOMOTOR
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 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: between
laryngeal inlet & vestibular
fold.
2- Ventricle: a depression
extending laterally
between vestibular & vocal
folds.
3- Infraglottic cavity: lies
between the vocal fold &
lower border of cricoid
cartilage.
It is continuous with the
trachea inferiorly.
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Superior laryngeal artery – branch of
superior thyroid artery
Inferior laryngeal artery – branch of
inferior thyroid artery
Veins accompany the arteries