Clinical Anatomy Larynx : Part - 1

Question 1

What are the cartilages of larynx ?

Answer 1

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

Question 2

What is cartilage of wrisberg ?

Answer 2

Cuneiform cartilage

NERVE OF WRISBERG IS sensory part of facial nerve

Question 3

What is the cartilage of santorini?

Answer 3

Corniculate

Question 4

What are the principle cartilages of larynx?

Answer 4

Thyroid
Cricoid
Two - arytenoids

Question 5

What is the oblique line of thyroid ?

Answer 5

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

Question 6

What are the muscles attached to the oblique line of thyroid cartilage ?

Answer 6

Sternothyroid
Thyrohyoid
Thyropharyngeus (part of inferior constrictor muscle )

Question 7

Thyroid angle in males and females ?

Answer 7

Males : 90 degrees - prominence is adams apple
Females :120 degrees

Question 8

Posterior aspect of thyroid cartilage gives attachment to what structures ?

Answer 8

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

Question 9

Muscles attached to the posterior border of thyroid cartilage ?

Answer 9

Longitudinal muscles / dilators of pharynx

Stylopharyngeus
Salphingopharyngeus
Palatopharyngeus

These muscles are inserted as conjoint tendon into the posterior border of thyroid cartilage

Question 10

Attachment of Epiglottis to hyoid is by?

Answer 10

Hyoepiglottic ligament

This ligament divides the Epiglottis into a SUPRAHYOID PART AND INFRAHYOID PART

Question 11

What is the only complete ring cartilage of larynx ?

Answer 11

Cricoid cartilage also known as signet ring cartilage

Question 12

What is the foundation stone of larynx ?

Answer 12

Cricoid cartilage

Question 13

Level at which cricoid cartilage is situated ?

Answer 13

C6 vertebrae

Question 14

Cricoid cartilage structure?

Answer 14

Anteriorly - arch
Posteriorly - lamina

Question 15

Injury to cricoid causes what ?

Answer 15

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

Question 16

Synechiae formation is reduced by which drug ?

Answer 16

Mitomycin c

Used in

Laryngeal stenosis repair surgery (since healing again occurs by fibrosis)

Nasal packs following FESS

Choanal atresia

Question 17

What type of joint is cricoarytenoid joint ?

Answer 17

Saddle joint

Question 18

What are the two processes of arytenoid ?

Answer 18

Muscular process (posterior)- attached to the muscles
Vocal process (anterior)-attached to vocal cords

Question 19

What are intrinsic and extrinsic membrane ?

Answer 19

Intrinsic membrane are those that attaches laryngeal structures to one another

Extrinsic membrane are those that attaches laryngeal structures to outside

Question 20

What are the extrinsic membranes?

Answer 20

Thyrohyoid
Criocotracheal
Hyoepiglottic

Question 21

What structures pierce the Thyrohyoid membrane ?

Answer 21

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

Question 22

In order to take biopsy from upper part of larynx , where should local anaesthesia be given?

Answer 22

In between hyoid and thyroid to paralyse the internal laryngeal nerve that supplies the upper part of larynx by piercing the Thyrohyoid membrane

Question 23

What are the intrinsic membranes of larynx?

Answer 23

Quadrangular membrane
Cricovocal / conus elasticus

Question 24

Upper border of quadrangular membrane is what?

Answer 24

Aryepiglottic fold

Question 25

Lower border of quadrangular membrane is what ?

Answer 25

False vocal cords / vestibular ligaments

Question 26

What are the boundaries of laryngeal inlet / epilarynx ?

Answer 26

Anterior- epiglottis Posterior - interarytenoid fold Lateral - aryepigloettic ligament / fold

Question 27

What happens in laryngomalacia / acute Epiglottitis ?

Answer 27

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

Question 28

Attachments of cricovocal membrane ?

Answer 28

Below - cricoid Above anteriorly to - thyroid Above posteriorly to - vocal process of arytenoid

Question 29

Upper part of cricovocal membrane forms what ?

Answer 29

True vocal cords

Question 30

What is glottis ?

Answer 30

Larynx at the level of true vocal cord is glottis Above glottis - supra glottis Below glottis - subglottis

Question 31

Gap between vocal cords

Answer 31

Gap between False vocal cords - Rima vestibuli True vocal cords - Rima glottitis Between the pair of true and false vocal cords - ventricle

Question 32

Gap between two quadrangular membrane

Answer 32

Vestibule

Question 33

What is cricothyroid membrane ?

Answer 33

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

Question 34

What are the intrinsic muscles of larynx?

Answer 34

Thyroepiglottis - opening of inlet Thyroarytenoid Cricothyroid Cricoarytenoid (lateral and posterior) Inter arytenoid Oblique arytenoid / aryepiglottis -closing of inlet

Question 35

What are the two parts of thyroarytenoid muscle ?

Answer 35

Lateral - thyroarytenoid Medial - vocalis = contraction of vocalis muscle reduces tension on the vocal cords

Question 36

Muscles that attach to the true vocal cords

Answer 36

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

Question 37

Only muscle with dual nerve supply

Answer 37

Interarytenoid