Larynx Flashcards
What is the larynx responsible for?
Responsible for the voice production (voice box or organ of phonation)
Upward and downward movements of larynx help in swallowing
what does it continue as?
Below it is continuous with the trachea
where is it located?
Located in the anterior neck at the level of C3 – C6 vertebrae
However, in children and in females it lies at a higher level
What is the larynx made up of?
Made up of three unpaired and three paired cartilages
what are the unpaired cartilages of the larynx?
thyroid cartilage
Cricoid cartilage
Epiglottis
what are the paired cartilages of the larynx?
Arytenoid cartilage
Corniculate cartilage
Cuniform cartilage
what is the thyroid cartilage made up of?
hyaline cartilage
what muscles attach to the oblique line on outer surface of the each lamina of the thyroid cartilage?
Sternothyroid muscle
Thyrohyoid muscle
Inferior constrictor muscle
Posterior borders of each lamina of the thyroid cartilage provide insertion to what?
Salpingopharyngeus muscle
Palatopharyngeus muscle
Stylopharyngeus muscle
The posterior surface of the thyroid cartilage in the median plane provides attachment to:
Thyroepiglittic ligament
Pair of vestibular ligament
Pair of vocal ligament
The cricoid cartilage sits at what level of the spinal cord?
C6
what is the cricoid cartilage made up of ?
hyaline cartilage
what is on each side of the lateral surface of the cricoid cartilage?
a circular facet for articulation with the inferior cornu of the thyroid cartilage
Posteriorly upper border of lamina of cricoid cartilage articulates with
base of the arytenoid cartilage
where is the epiglottis located?
Situated behind the hyoid bone and base of the tongue
what is the lower end of the epiglottis attached to?
connected with the back of the thyroid cartilage, by the thyroepiglottic ligament
what are the sides of the epiglottis connected to?
connected to the arytenoid cartilages by aryepiglottic folds
how is the anterior surface of epiglottis attached to the tongue?
connected to the tongue by medial and lateral glossoepiglotic folds
where is the Arytenoid cartilage located?
Situated at the back of the larynx
what is the arytenoid cartilage made up of?
hyaline cartilage
what are the two processes that project from the base of the arytenoid cartilage?
Vocal process: projects horizontally forwards and gives attachment to the vocal ligament
Muscular process: projects laterally and gives attachment to the posterior and lateral cricoarytenoid muscles
what are the laryngeal joints?
Includes paired crico-thyroid, crico-arytenoid and aryteno-corniculate joints
what Connects the cricoid cartilage with the first tracheal ring?
Cricotracheal ligament
what Connects narrow lower end of epiglottis to the posterior surface of thyroid angle
Thyroepiglottic ligament
how does the laryngeal cavity extend?
Extends from inlet of larynx to the lower border of cricoid cartilage where it is continuous with the lumen of the trachea
what are the boundaries of the laryngeal inlet?
Anterior – epiglottis
Posterior – interarytenoid fold
On each side – aryepiglottic fold
what are the 3 parts that the laryngeal cavity is divided into?
Vestibule or upper part
Ventricle or sinus of larynx - Middle part
Infraglottic compartment – lower part
what is the Rima glottidis
Gap between the vocal folds in front and the vocal process of arytenoid cartilages behind
what is the rima glottidis lined by
stratified squamous epithelium
what are the extrinsic elevator muscles of the larynx?
Digastric
Thyrohyoid
Stylohyoid
Mylohyoid
Geniohyoid
what are the extrinsic depressor muscles of the larynx?
Sternothyroid
Sternohyoid
Omohyoid
what are the intrinsic muscles of the larynx and their actions
Cricothyroid tenses the vocal cord
Posterior cricoarytenoid opens the rima glottidis
Lateral cricoarytenoid closes the rima glottidis
Transverse arytenoid closes the rima glottidis
Oblique arytenoid closes the rima glottidis
Thyroarytenoid relax the vocal cord
Vocalis relax the vocal cord
Thyepiglotticus opens the inlet of the larynx
Aryepiglitticus close the inlet of the larynx
where do muscles of the larynx develop from
from 4th – 6th pharyngeal arches
what is the blood supply of the muscles of the larynx
supplied by superior laryngeal and recurrent laryngeal nerves (braches of Vagus)
what is the sensory nerve supply of the larynx
Up to the vocal folds (including the vocal fold): internal laryngeal nerve
- Below the vocal folds: recurrent laryngeal nerve
what is the motor nerve supply of the larynx
All intrinsic muscles supplied by recurrent laryngeal nerve
Exception: cricothyroid – external laryngeal nerve
what is semon’s law?
in progressive lesions of the recurrent laryngeal nerve the abductors of the vocal cords (posterior crico-arytenoids) are first to be paralysed and last to recover as compared to the adductors.
This is because the nerve supplying the abductors are longer and has less thresh-hold, hence these branches are affected first.
what is the blood supply of the larynx?
Vocal folds and above: superior laryngeal vessels
Below the vocal folds: inferior laryngeal vessels
what is the lympathic drainage of the larynx
Lymph vessels drain into deep cervical lymph nodes
what are the boundaries of the rima glottis
In front – angle of thyroid cartilage
Behind – interarytenoid folds of mucous membrane
On each side – vocal folds in the anterior three-fifth and vocal process of arytenoid cartilage in the posterior three-fifth
