Anatomy of larynx Flashcards
What is the larynx basically?
Tube created by membranes, cartilages and muscles
How does the larynx relate to the hyoid bone?
It lies below the hyoid bone
Where does the larynx begin?
Laryngeal inlet
Where does the larynx end?
Lower border of cricoid cartilage
C6 vertebral level
What is the continuation of the larynx?
Trachea
How many important cartilages of the larynx are there? What are the different groups?
Three single cartilages
One paired cartilage
What are the three single cartilages of the larynx?
Thyroid cartilage
Cricoid cartilage
Epiglottis
What is the paired cartilage of the larynx?
Aretynoid cartilages
What are the parts of the thyroid cartilage?
Lateral plates
Laryngeal prominence
Inferior horn
What is the laryngeal prominence?
Where the two lateral plates of the thyroid cartilag meet in the anterior midline
What is the laryngeal prominence of the thyroid cartilage commonly known as?
Adam’s apple
What is the inferior horn of the thyroid cartilage?
Postero-inferior projection
What does the inferior horn of the thyroid cartilage do?
Articulates with the cricoid cartilage
What is the signifiance of the inferior horn of the thyroid cartilage articulating with the cricoid cartilage in a synovial joint?
Thyroid cartilage can move on cricoid cartilage
What is different about the cricoid cartilage compared to other cartilages of the larynx and trachea?
Forms a complete ring
others are incomplete
What type of joint connects the inferior horn of the thyroid cartilage to the cricoid cartilage?
Synovial joint
What is the shape of the cricoid cartilage?
Wider and flatter at the back
than at the front
What shape is the epiglottis?
Leaf-shaped
What is the relative position of the aretynoid cartilages in the larynx?
Posteriorly
Superior to cricoid cartilage on either side
What do the aretynoid cartilages attach to?
The cricoid cartilage on either side
How do the aretynoid cartilages attach to the cricoid cartilage?
Synovial joints
What does the epiglottis attach to?
Postero-superior surface of thyroid cartilage inferiorly
Body of hyoid bone superiorly
How many membranes of the larynx are there?
Four
What are the membranes of the larynx?
Thyro-hyoid membrane
Crico-thyroid membrane
Crico-tracheal membrane
Quadrangular membrane
What does the thyro-hyoid membrane attach to?
Superiorly the hyoid bone
Inferiorly the thyroid cartilage
What does the crico-thyroid membrane attach to?
Superiorly the thyroid cartilage
Inferiorly the cricoid cartilage
What does the crico-tracheal membrane attach to?
Superiorly the cricoid cartilage
Inferiorly the first ring of cartilage of the trachea
What is the clinical signifiance of the cricothyroid membrane?
Cricothyroidotomy
When is a cricothyroidotomy done?
Patient cannot breathe
cannot be intubated or ventilated
How is a cricothyroidotomy done?
Palpate for the cricothyroid membrane
make an incision into it
What does the quadrangular membrane attach to?
Sides of epiglottis superiorly
Posterior surface of thyroid cartilage antero-inferiorly
Aretynoid cartilages postero-inferiorly
What is the free superior border of the quadrangular membrane called?
Aryepiglottic fold
How does the free superior border of the quadrangular membrane form the aryepiglottic fold?
Thickens at this point
What is the laryngeal inlet?
Opening into the larynx
What forms the laryngeal inlet?
The aryepiglottic folds
What is the free inferior border of the quadrangular membrane called?
The vestibular ligament/false vocal cord
How does the free inferior border of the quadrangular membrane frorm the vestibular ligament/false vocal cord?
Thickens at this point
What is the free superior border of the crico-thyroid membrane called?
The vocal ligament/true vocal cord
How does the free superior border of the crico-thyroid membrane form the vocal ligament/true vocal cord?
Thickens at this point
What lines the surface of the larynx?
Mucous membrane
What are the three areas of the larynx?
Supraglottis
Glottis
Infraglottis
What is the supraglottis?
Area of the larynx above the vestibular ligament/false vocal cords
What is the glottis?
Area of the larnx that contains the vestibular ligament/false vocal cords and the vocal ligament/true vocal cords
What is the infraglottis?
Area of the larynx below the vocal ligament/true vocal cords
What is located between the vestibular ligament/false vocal cords and the vocal ligament/true vocal cords?
Ventricle posteriorly
Saccule anteriorly
What are the ventrcle and saccule?
Recesses between the vestibular ligament/false vocal cords and the vocal ligament/true vocal cords
What is the function of the ventricle and saccula?
Contain mucous glands
produce mucus
keep larynx mois
What type of epithelium lines the larynx?
Respiratory epithelium - psueodostratified ciliated columnar epithelium
What is the exception to psueodostratified ciliated columnar epithelium lining the respiratory tract?
Vocal ligament/true vocal cords is lined with stratified squamous epithelium
Why are the vocal ligaments/true vocal cords lined with stratified squamous epithelium?
To protect against of abrasion of air moving into and out of larynx
What is the rima glottidis?
The opening between the vocal ligaments/true vocal cords
How can you tell the orientation of a view of the larynx?
Point of rima glottidis is anterior
How can the larynx be viewed?
Laryngoscope
Nasoendoscopy
When is a laryngoscope used to view the larynx?
Intubation - placing a tube in the infraglottis
When is a nasoendoscope used to view the larynx?
To visualise the larynx
What body system is the larynx a part of?
Respiratory system
What are the functions of the larynx? Which is its main function?
Ventilation - air in and out of lungs
Airway protection - preventing aspiration - main function
Cough
Phonation - producing sound