Clinical Anatomy Larynx : Part - 1 Flashcards
What are the cartilages of larynx ?
Three paired and three unpaired cartilages - totally nine in number
Paired cartilages : seen in posterior view
Arytenoid / pyramidal cartilage
Corniculate / santorini cartilage
Cuneiform / wrisberg
Unpaired cartilages: seen in anterior view
Epiglottis
Thyroid
Cricoid
What is cartilage of wrisberg ?
Cuneiform cartilage
NERVE OF WRISBERG IS sensory part of facial nerve
What is the cartilage of santorini?
Corniculate
What are the principle cartilages of larynx?
Thyroid
Cricoid
Two - arytenoids
What is the oblique line of thyroid ?
On the external aspect of thyroid cartilage , there’s a line extending from the inferior aspect of superior Cornu to the lower border of thyroid cartilage called the OBLIQUE LINE
What are the muscles attached to the oblique line of thyroid cartilage ?
Sternothyroid
Thyrohyoid
Thyropharyngeus (part of inferior constrictor muscle )
Thyroid angle in males and females ?
Males : 90 degrees - prominence is adams apple
Females :120 degrees
Posterior aspect of thyroid cartilage gives attachment to what structures ?
In the median plane on the posterior aspect of thyroid cartilage , the attachment from above downwards is as follows
Thyroepiglottic ligament
A pair of Vestibular ligaments
A pair of Vocal ligaments
Muscles attached to the posterior border of thyroid cartilage ?
Longitudinal muscles / dilators of pharynx
Stylopharyngeus
Salphingopharyngeus
Palatopharyngeus
These muscles are inserted as conjoint tendon into the posterior border of thyroid cartilage
Attachment of Epiglottis to hyoid is by?
Hyoepiglottic ligament
This ligament divides the Epiglottis into a SUPRAHYOID PART AND INFRAHYOID PART
What is the only complete ring cartilage of larynx ?
Cricoid cartilage also known as signet ring cartilage
What is the foundation stone of larynx ?
Cricoid cartilage
Level at which cricoid cartilage is situated ?
C6 vertebrae
Cricoid cartilage structure?
Anteriorly - arch
Posteriorly - lamina
Injury to cricoid causes what ?
Leads to healing by fibrosis
Since it’s a complete cartilage it causes laryngeal stenosis as a result of fibrosis
This is the reason for giving incision at 2/3/4 tracheal ring for tracheostomy
Synechiae formation is reduced by which drug ?
Mitomycin c
Used in
Laryngeal stenosis repair surgery (since healing again occurs by fibrosis)
Nasal packs following FESS
Choanal atresia
What type of joint is cricoarytenoid joint ?
Saddle joint
What are the two processes of arytenoid ?
Muscular process (posterior)- attached to the muscles
Vocal process (anterior)-attached to vocal cords
What are intrinsic and extrinsic membrane ?
Intrinsic membrane are those that attaches laryngeal structures to one another
Extrinsic membrane are those that attaches laryngeal structures to outside
What are the extrinsic membranes?
Thyrohyoid
Criocotracheal
Hyoepiglottic
What structures pierce the Thyrohyoid membrane ?
Internal laryngeal nerve (a branch of Superior laryngeal nerve) and superior laryngeal vessels that supplies the upper part of larynx
Branches of superior laryngeal nerve - internal and external laryngeal nerve
In order to take biopsy from upper part of larynx , where should local anaesthesia be given?
In between hyoid and thyroid to paralyse the internal laryngeal nerve that supplies the upper part of larynx by piercing the Thyrohyoid membrane
What are the intrinsic membranes of larynx?
Quadrangular membrane
Cricovocal / conus elasticus
Upper border of quadrangular membrane is what?
Aryepiglottic fold
Lower border of quadrangular membrane is what ?
False vocal cords / vestibular ligaments
What are the boundaries of laryngeal inlet / epilarynx ?
Anterior- epiglottis
Posterior - interarytenoid fold
Lateral - aryepigloettic ligament / fold
What happens in laryngomalacia / acute Epiglottitis ?
The epiglottis becomes bulky falls down when the patient lies supine closes the inlet of larynx and causes respiratory distress
If the patient lies prone then the distress is relieved
Attachments of cricovocal membrane ?
Below - cricoid
Above anteriorly to - thyroid
Above posteriorly to - vocal process of arytenoid
Upper part of cricovocal membrane forms what ?
True vocal cords
What is glottis ?
Larynx at the level of true vocal cord is glottis
Above glottis - supra glottis
Below glottis - subglottis
Gap between vocal cords
Gap between
False vocal cords - Rima vestibuli
True vocal cords - Rima glottitis
Between the pair of true and false vocal cords - ventricle
Gap between two quadrangular membrane
Vestibule
What is cricothyroid membrane ?
It is the anterior thickening of the cricovocal membrane and is a part of intrinsic membrane
This membrane allows cricothyrotomy/coniotomy/inferior laryngotomy during can’t intubate can’t oxygenate situation - this is usually done when emergency tracheostomy can’t be done when obstruction is above the level of vocal cords
What are the intrinsic muscles of larynx?
Thyroepiglottis - opening of inlet
Thyroarytenoid
Cricothyroid
Cricoarytenoid (lateral and posterior)
Inter arytenoid
Oblique arytenoid / aryepiglottis -closing of inlet
What are the two parts of thyroarytenoid muscle ?
Lateral - thyroarytenoid
Medial - vocalis = contraction of vocalis muscle reduces tension on the vocal cords
Muscles that attach to the true vocal cords
Adductors - all muscles except posterior cricoarytenoid (safety muscle if larynx )
Abductors - posterior cricoarytenoid
Decreases tension over vocal cords - vocalis
Increases tension over the vocal cords - cricothyroid
Only muscle with dual nerve supply
Interarytenoid
