SAQ 6 Flashcards
The Larynx
- specially modified for vocalization.
- It is situated anteriorly in the neck, below the hyoid bone and the tongue.
- It has a marked anterior projection, the laryngeal prominence (Adam’s apple).
- Related anteriorly to it is the skin and fasciae and laterally, the thin strap muscles of the neck, the thyroid gland, the great vessels of the neck, and the vagus nerves. posteriorly related are the vertebral column and the prevertebral muscles separated from them by the laryngopharynx.
The Larynx Function:
• Function:
– Organ of vocalization or phonation
– Air passage
– Sphincter
The Larynx Extent:
• Extent:
– Between the root of the tongue and the trachea
– In the adult, it extends between C3-C6.
The Larynx Communications:
• Communications:
– Superiorly with the laryngopharynx through the
laryngeal inlet
– Inferiorly with the trachea
Laryngeal Cartilages
- paired
- unpaired
two types: hyaline and elastic cartilages of which there are 2 groups: – Unpaired: thyroid, cricoid, & epiglottis – Paired: arytenoids, corniculates, & cuneiforms
Laryngeal membranes & ligaments
- extrensic
- intrinsic
– Extrinsic – attach structures inside the larynx to structures outside the larynx – Intrinsic – attach structures of the larynx together
The thyroid cartilage
The thyroid cartilage is a hyaline cartilage
located under the hyoid bone. It is made up of two laminae meeting in the midline. The
posterior border extends upward to form the
superior horn, and downward to form the
inferior horn.
The thyroid cartilage Landmarks:
Landmarks: – Thyroid notch – Laryngeal prominence (where 2 laminae meet) – Superior & inferior thyroid tubercles – Oblique line
The thyroid cartilage Articulations
Articulations: Cricothyroid – between the
inferior cornu of the thyoid cartilage and the
lateral side of the cricoid cartilage
The thyroid cartilage Attachments:
Attachments:
– To cricoid by the cricothyroid ligament
– To epiglottis by the thyroepiglottic ligament
– To vocal process of arytenoid by vocal ligament
– To hyoid bone by thyrohyoid membrane
Cricoid Cartilage
The cricoid is a hyaline cartilage shaped like a signet ring; it consists of an anterior arch and a posterior quadrangular lamina.
Cricoid Cartilage Articulations
• Articulations:
– Cricothyroid
– Cricoarytenoid
Cricoid Cartilage Attachments
• Attachments: – To thyroid by cricothyroid ligament – To trachea by the cricotracheal ligament
Arytenoid Cartilages
These are a pair of cartilages located on the lateral side of the superior border of cricoid
lamina. Each is a 3-sided pyramid with 3 surfaces, a base, an apex, and 2 processes:
vocal & muscular.
Arytenoid Cartilages Articulations:
Articulations:
– With cricoid lamina
– With corniculate cartilage
Arytenoid Cartilages Attachments:
Attachments: – To thyoid cartilage by the vocal ligament – To epiglottis by the quadrangular membrane
Epiglottic Cartilage
This is a leaf-like elastic cartilage which projects upward behind the tongue and hyoid bone. Its stalk is attached to the back of the thyroid cartilage. • During deglutition, it bends back over the laryngeal inlet. In humans, it is somewhat degenerate in function and is not essential to swallowing.
Epiglottic Cartilage Attachments:
Attachments: – To thyroid – To hyoid – Arytenoids – To the tongue
Smaller Cartilages Corniculate
Corniculate cartilages – are 2 small conical nodules of yellow elastic cartilage. They lie on the apices of the arytenoid cartilages
and serve to prolong them backward and medialward. They are enclosed within the posterior parts of the aryepiglottic folds.
Smaller Cartilages Cuneiform
Cuneiform cartilages – also formed of yellow elastic cartilage, are small, rod-like bodies in the aryepiglottic fold anterior to the
corniculate cartilages.
Smaller Cartilages Tritiate
Tritiate (triticeal) cartilage – are 2 small nodules of elastic cartilage situated one on either side above the larynx within the posterior free edge of the thyrohyoid
*Find the tritiate in between the tip of the greater horn of the hyoid bone, and the tip of the superior horn of the thyroid Cartilage.membrane
Membranes & Ligaments
*Extrinsic membrane
Extrinsic
– Thyrohyoid membrane
– Cricotracheal ligament
– Hyoepiglottic ligament
Membranes & Ligaments
*Intrinsic membrane
Intrinsic
– Quadrangular membrane: between the epiglottis and arytenoid cartilages. Its inferior border forms the vestibular ligaments.
*Quadrangular membrane is covered by mucous membrane.
Superior border of the quadrangular membrane is called the Aryepiglottic fold.
Inferior border is the vestibular fold and ligament.
Membranes & Ligaments
*Intrinsic ligament
Intrinsic
– Cricothyroid ligament
• Median portion
• Lateral portion – its upper edge is the
vocal ligament; together the vocal ligament and the lateral cricothyroid ligament form the
conus elasticus
– Thyroepiglottic ligament
Boundaries & Subdivisions bounded by:
bounded:
– Anteriorly by the epiglottis
– Laterally by the aryepiglottic folds
– Posteriorly by the mucous membrane between the arytenoid cartilages
Boundaries & Subdivisions Parts
• Parts:
– Vestibule – space between the inlet and the vestibular folds
– Ventricle – space between the vestibular folds and the vocal folds; extends anteriorly to form the saccule; the saccule contains
mucous glands to lubricate the vocal folds
– Infraglottic cavity – space between the vocal folds and the inferior border of the cricoid cartilage Rima vestibuli: space between the right & left vestibular folds
Rima glottidis: space between the right & left vocal folds
Extrinsic Laryngeal Muscles
These are muscles which elevate or depress the larynx either directly or through its attachment to the hyoid bone through the
thyrohyoid membrane and hyoepiglottic ligament.
Elevators of the larynx:
Elevators of the larynx: – Digastric – Stylohyoid – Mylohyoid – Geniohyoid – Stylopharyngeus – Salpingopharyngeus – Palatopharyngeus
Depressors of the larynx:
Depressors of the larynx: – Sternothyroid – Sternohyoid – Omohyoid -*Stylopharyngeus
Cricothyroid
Chief tensor of vocal ligament
Posterior cricoarytenoid
Abductor of vocal folds