The Larynx Flashcards
What is the larynx, where is it located and its functions?
Part of respiratory tract between oropharynx and trachea. Located between C3 and C6, below hyoid bone but will move when swallowing and is slight higher in newborns. It transports air, acts as a protective sphincter and is involved in phonation
Name the laryngeal cartilages
- Epiglottis
- Thyroid
- Cricoid (only complete ring)
- Arytenoid
- Corniculate and cuneiform
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where does the epiglottis project and where is it attached too?
- Projects upwards and backwards into the pharynx behind the posterior part of tongue.
- Attaches to thyroid cartilage via thyroepiglottic ligament.
- Attaches to hyoid bone by the hypoepiglottic ligament
Describe the structure of the thyroid cartilage
- Left and right laminae,
- Superior and Inferior horns (superior attach to hyoid, inferior to cricoid)
- Superior thyroid notch
- Thyroid angle = laryngeal prominence (adams apple)
- Oblique line for muscle attachment.
Describe the structure of the cricoid cartilage
- Articulates with arytenoid and thyroid
- Shape of a signet ring
Describe structure of the arytenoid cartilages
- Articulates with sloping shoulders of cricoid lamina and superiorly with corniculate cartilage.
- Vocal process anteriorly for attachment of vocal ligament
- Muscular process posteriorly for attachment of the posterior and lateral crico-arytenoid muscles
- Depressions for vestibular ligament and attachment of vocalis muscle.
Describe structure of thyro-htoid membrane
- Extends from thyroid laminae and superior horns to greater horns of hyoid.
- Thickened anteriorly and posteriorly as the median and lateral thyro-hyoid ligaments.
- Pierced by superior laryngeal vessels and nerve.
What is the fibro-elastic membrane?
It is elastic connective tissue underneath the laryngeal muscous membrane and strtches between laryngeal cartilages and forms the fibro-elastic membranes.
What is the fibro-elastic membrane separated by?
The laryngeal ventricle to form superiorly quadrangular membrane and inferiorly conus elasticus.
Describe the positioning of the quadrangular membrane
It extends between lateral aspect of epiglottis, arytenoid and corniculate cartilages. The edges form the aryepiglottic fold and the vestibular ligament which when covered by mucous membrane forms vestibule fold.
What is the clinical significance of the conus elasticus?
(cricovocal membrane)
- Blends anteriorly with the median cricothyroid ligament which is the site of emergency access to airway (Tracheotomy)
Describe the functions of the vocal cord
It controls laryngeal diameter for:
- Speech
- Coughing/sneezing,
- Raising intra-abdominal pressure
What widens or alters the tension of rima glottis?
the muscles within and adjacent to the vocal folds.
What is the vestibule?
Between the laryngeal inlet and vestibular folds
What is the laryngeal ventricle
Recess between vestibular and vocal folds which leads to the saccule which lubricates the vocal folds