Clinical Anatomy Of Larynx Part 2 Flashcards
Division of larynx by true vocal cords
Above the level of true vocal cords - supraglottis
At the level of true vocal cords - glottis
Below the level of true vocal cords - sub glottis
What are the subsites of supraglottis ?
Epiglottis
Aryepiglottic fold
Arytenoid
Quadrangular membrane
False vocal cords
Vestibule
Ventricle
What is epilarynx ?
Epilarynx is the inlet of larynx ; formed by
Anterior - epiglottis
Laterally - Aryepiglottic fold
Posteriorly - arytenoids
What is the anterior and posterior commissure of true vocal cords ?
Anterior commissure is the point of attachment to the thyroid cartilage
Posterior commissure is the attachment of true vocal cords to the vocal process of arytenoid
What are the parts of true vocal cords ?
Cartilagenous part and membranous part
Anterior 2/3 rd - membranous and vibrates during talking
Posterior 1/3 rd - cartilagenous and is responsible for adduction and abduction of vocal cords
What is the point of maximum vibration of true vocal cords ?
Mid point of membranous part ; this point is most commonly affected due to vocal abuse , most common site of nodule or polyp of formation
Anterior 1/3 rd and posterior 2/3
What are the boundaries of glottis ?
Upper boundary - lower border of ventricle
Lower boundary - 1 cm below the true vocal cord’s edge
With what the anterior commissure of true vocal cords is attached to the thyroid cartilage ?
It is attached with the help of BROYLE ‘ S LIGAMENT also known and ANTERIOR COMMISSURE LIGAMENT
Purpose of this tendon is to limit the spread of carcinoma ; all the membrane of larynx prevent the spread of tumour from the larynx
What are the cavities of larynx ?
From above downwards :
Inlet / epilarynx
Vestibule
Rima vestibuli
Ventricle
Rima glottidis
Subglottis
What is saccule of larynx ?
The lining epithelium of false vocal cords is not just continuous over the true vocal cords but before lining the true vocal cords , the epithelium is forming a sac like structure called saccule that is having mucous glands in it
What the other name of saccule and purpose of saccule ?
Saccule is also called as oil can of larynx
The purpose of this saccule is to lubricate the true vocal cords as it is constantly rubbing against one another
This lubrication is essentially by the saccule as the true vocal cords are lined by non keratinised stratified squamous epithelium which doesn’t have mucus glands
What is the ventricle otherwise called as ?
Sinus of morgagni of larynx
What is laryngocoele?
Laryngocele is the enlargement of saccule
This enlargement occurs when the person blows down against a closed glottis (glottis are closed when the person speaks) and air doesn’t find way to move down hence enters the saccule causing it’s enlargement
In whom laryngocoele is commonly seen ?
Weight lifters
Trumpet blowers
Glassblowers
Tumours of ventricles
CAN ALSO BE SEEN CONGENITALLY
What are the types of laryngocele ?
Intrinsic
Extrinsic : pierces the Thyrohyoid membrane
Clinical features of laryngocele
Difficulty in breathing (due to obstruction of lumen of larynx)
Voice change (due to compression of vocal cords)
Infection leads to the formation of laryngopyocele
How to identify that a neck swelling is laryngocele ?
The size of the swelling increases on Valsalva manoeuvre
Bryce sign : sudden gush of hissing sound produced on compression
Management of laryngocele
Excision - either externally or endoscopically
What is the primary function of larynx ?
The earliest function of larynx is protection of airways
This protection is achieved with the help of three sphincters
Inlet / epilarynx - MOST EFFECTIVE SPHINCTER
False vocal cords - PREVENTS ASPIRATION
True vocal cords
Pre epiglottic space is also known as
Space of BOYER
Boundaries of pre-epiglottic / space of Boyer
Anteriorly - hyoid , Thyrohyoid ,thyroid
Posteriorly - epiglottis (infra hyoid part)
Superiorly - Hyoepiglottic ligament
Contents of pre epiglottic space
Fats , LYMPHATICS ,vessels
Important route of spread of carcinoma of larynx
Para epiglottic space is also known as
Space of tucker
Boundaries of para-epiglottic / space of tucker
Anteriorly - communicates with the pre-epiglottic space
Posteriorly - pyriform fossa
Laterally - thyroid ala
Medially - quadrangular membrane , ventricle , cricovocal ‘ conus elasticus
Contents of para - epiglottic space
Same as pre - epiglottic space
What is reinke’s space ?
Space in the true vocal cords bounded by the vocal epithelium medially and vocal ligament laterally
Boundaries of reinke’s space
Medially : vocal epithelium
Laterally : vocal ligament
Anteriorly : anterior commissure
Posterior : posterior commissure
Contents : loose areolar tissue
Significance : enables the free movement of vocal cords
Lymphatic drainage of larynx
Supra glottis - richest supply of lymphatics
Glottis - no lymphatics
Sub glottis - some lymphatics
Where does supra glottis drain into ?
Upper and middle deep cervical (part of lateral group of lymph nodes) - level 2 & 3
Where does glottis drain into ?
Glottis do not have lymphatics
So there will be , no spread of carcinoma and reinke’s edema is seen in vocal cords as there are no lymphatics
Where does subglottis drain into ?
Lower deep cervical and anterior group of lymph nodes (level 4 and 6)
Anterior group - pre tracheal /pre cricoid also known as DELPHIAN NODES
On the whole larynx drains into what levels of lymph nodes?
Level 2 , 3 , 4 ,6
Common anterior lesions
Nodules and polyp
Common posterior lesion
Granuloma
Position for direct laryngoscope
Boyle’s position : extension at atlanto-occipital joint and flexion at cervicothoracic joint
What is stroboscope used for ?
To find the even the smallest lesion of vocal cords
Light appears in flashes
Average anteroposterior diameter of larynx for male and female
Male : 36mm
Female : 26mm
What makes it possible for the infant to breathe simultaneously while suckling the milk?
High larynx
What are the hyaline and elastic cartilages of larynx ?
Hyaline : will undergo calcification between 25-65 yrs of age
Thyroid
Cricoid
Most of arytenoid
Elastic cartilage : will not undergo calcification
Epiglottis
Corniculate
Cuneiform
Tip of arytenoid
Muscle of whispering
Lateral cricoarytenoid
Why vocalis is called the modulater?
Anterior part of vocalis - tense the vocal cords
Posterior part of vocalis - relaxes the vocal cords
