by dr. musaed al fayez. specialized organ at the inlet of air passage. function : 1- protective...
TRANSCRIPT
ByDr. Musaed Al Fayez
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.
Unpaired cartilages Epiglottis Thyroid cartilage Cricoid
Paired cartilages Arytenoid Corniculate Cuneiform All cartilages are
hyaline except the epiglottis (elastic)
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.
The Laryngeal cartilage are Nine
3 single & 3 Paired
Single: Thyroid Cricoid Epiglottis.
Paired: Arytenoids Corniculate Cuneiform.
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.
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.
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.
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. 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.
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 All intrinsic muscles lie inside the larynx cricothyroid
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.
Posterior cricoarytenoid is the only abductor of the vocal cords.
Posterior cricoarytenoids
Lateral cricoarytenoid
Interarytenoid muscles: Transverse & Oblique
Thyroarytenoid muscle
Aryepiglottic muscles
MOTORAll muscles of the larynx are supplied the
recurrent laryngeal nerve EXCEPT Cricothyroid – supplied by external laryngeal
branch of superior laryngeal nerve. SENSORY & SECRETOMOTOR
Above Vocal Cords: Internal laryngeal Below Vocal Cords: Recurrent laryngeal
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.
Superior laryngeal artery – branch of superior thyroid artery
Inferior laryngeal artery – branch of inferior thyroid artery
Veins accompany the arteries