Anatomy of larynx is a complicated topic for many students. This is our attempt at making the topic a little easier for them to understand with the practical aspects of learning the anatomy. Larynx is the voice box present in the neck above trachea and also forms an important pathway for air passage for breathing. The most important structure in the neck so as to support our survival nad the disease which are quite common causes of change in voice as a complaint, it becomes even more important to understand it's exact anatomy for students in medical field so as to diagnose and treat the patient correctly. As they say you can only diagnose a disease when you know what a normal structure looks like. Anatomy of neck is very sophisticated in ways it accomodates many evident blood vessels and nerves along with the thyroid gland which all reside in close proximity with larynx. And all the structures pertaining to larynx as in cartilages, ligaments, vocal folds and epiglottis are equally delicate and can have injury if person operating does not have the correct knowledge of anatomy of larynx along with its physiology. The most common of pathologies of larynx relate to the vocal cord dysfunction due to physiological or anatomical disturbance in their structure and can be very distressing to the patient, hence the need to understand it's anatomy and physiology.

1. ANANTOMY AND
PHYSIOLOGY OF
LARYNX
DR. SANKALP KESHARI (MS)
ASSISTANT PROFESSOR
DEPT. OF ENT & HNS
MLN MEDICAL COLLEGE , PRAYAGRAJ

2. INTRODUCTION
 The larynx is the upper extended part of the lower
respiratory tract.
 Made up of series of cartilages that are inter connected
by ligaments and fibrous membranes
 Lies in the upper part of neck, anteriorly in the midline
 Extends from root of tongue to trachea
 Lies in front of 3rd to 6th cervical vertebra
 Before puberty size is almost same in males and
females
 At puberty larynx grows rapidly in males and attend a
bigger size than females

3.  Thyroid cartilage is prominent in
males- ADAM’S APPLE
 It moves vertically and in
anteroposterior direction during
swallowing and phonation.
 It can also be passively moved from
side to side producing a
characteristic grating sensation
called laryngeal crepitus.

4. PHYSIOLOGY OF LARYNX
 1. Protection of lower airways
 2. Phonation
 3. Respiration
 4. Fixation of the chest.

5. Laryngeal framework.

6. LARYNGEAL CARTILAGES
Unpaired: Thyroid, cricoid and epiglottis.
Paired: Arytenoid, corniculate and cuneiform

7. Thyroid Cartilage
 It is the largest of all.
 Its two alae meet anteriorly forming an angle of 90° in
males and 120° in females.
 Its function is to shield larynx from injury and provide an
attachment to vocal cords
 Shied shaped, open posteriorly, angulated anteriorly

8. Cricoid Cartilage
 Signet ring shaped
 Stronger than thyroid
cartilage.
 Lamina – 2 to 3 cm
from above
downwards,
considerably broader
than anterior arch.

9.  Important from structural & functional point of view
Base for entire larynx
Support to arytenoid
Attachment to intrinsic muscles
Only part of cartilagenous framework that
forms continuous 360 degree ring
Once injured or strictured , difficult to
resect while preserving laryngeal function

10.  3. Epiglottis. It is a leaf-like, yellow, elastic cartilage
forming anterior wall of laryngeal inlet.
 A stalk-like process of epiglottis (petiole) attaches
the epiglottis to the thyroid angle just above the
attachment of vocal cords.
 Anterior surface of epiglottis is separated from
thyrohyoid membrane and upper part of thyroid
cartilage by a potential space filled with fat— the
pre-epiglottic space.

11.  4. Arytenoid cartilages. They are paired.
Each arytenoid cartilage is pyramidal in
shape. It has a base which articulates with
cricoid cartilage.
 5. Corniculate cartilages (of Santorini) (Corn
= horn). They are paired. Each articulates
with the apex of arytenoid cartilage as if
forming its horn.
 6. Cuneiform cartilages (of Wrisberg). They
are rod shaped. Each is situated in
aryepiglottic fold in front of corniculate
cartilage and provides passive supports to the
fold.

12.  Thyroid, cricoid and most of the arytenoid
cartilages are hyalin cartilages
 epiglottis, corniculate, cuneiform and tip of
arytenoid near the corniculate cartilage are
elastic fibrocartilage.

14. Supraglottis
 Consists of ventricles,
false cords, laryngeal
surface of epiglottis,
aryepiglottic folds and the
mucosal expanse.
 Posterior tapering shape
reduces area of mucosa in
posterior region
 So majority of SG tumors
are epiglottic

15. Glottis
 Consists of true cords,
anterior commissure and
posterior commissure
 Narrow triangular space
between the true cords is
called rima glottis
 Anterior 2/3 is membranous
 Posterior third consists of
vocal processes of
arytenoids
 Posterior 1/3 of cords and
covering mucosa are called
posterior commissure

16. Sub-glottis
 Begins about 5mm below free
margins of VC
 Consists of a mobile upper
and fixed lower part

17. Mucosa
 Mucosa of glottic and Supraglottic regions
is stratified squamous epithelium.
 Mucosa of ventricles and sub-glottic
regions is pseudo-stratified ciliated
epithelium
 Supra and sub glottic regions particularly
ventricles are rich in submucosal mucous
or minor salivary glands while glottis is
not.

18. LARYNGEAL JOINTS
 Cricothyroid Joint. It is a synovial joint. Each is formed by
the inferior cornua of thyroid cartilage with a facet on the
cricoid cartilage.
 Cricoid cartilage rotates at these joints on a transverse axis
which passes transversely through these joints.
 Cricoarytenoid Joint. It is a synovial joint surrounded by
capsular ligament. It is formed between the base of arytenoid
and a facet on the upper border of cricoid lamina.
 Two types of movements occur:
 (i) rotatory
 (ii) gliding

20. LARYNGEAL MEMBRANES
 1. Extrinsic membranes and ligaments
 (a) Thyrohyoid membrane
 (b) Cricotracheal membrane
 (c) Hyoepiglottic ligament

21.  2. Intrinsic membranes and ligaments
 (a) Cricovocal membrane. It is a triangular fibroelastic membrane.
 Its upper border is free and stretches between middle of thyroid angle to
the vocal process of arytenoid and forms the vocal ligament
 Its lower border attaches to the arch of cricoid cartilage.
 thus, with its fellow on the opposite side, forms conus elasticus where
subglottic foreign bodies sometimes get impacted.

23.  b) Quadrangular membrane. It lies deep to mucosa of
aryepiglottic folds and is not well-defined.
 (c) Cricothyroid ligament. The anterior part of cricothyroid
membrane is thickened to form the ligament and its lateral
part forms the cricovocal membrane.
 (d) Thyroepiglottic ligament. It attaches epiglottis to thyroid
cartilage.

24. CAVITY OF THE LARYNX
 Inlet of Larynx. It is an oblique opening bounded
anteriorly by free margin of epiglottis; on the sides, by aryepiglottic folds and
posteriorly by interarytenoid fold
Vestibule. It extends from laryngeal inlet to vestibular folds.
anterior wall is formed by posterior surface of epiglottis; sides by the aryepiglottic
folds and posterior wall by mucous membrane over the anterior surface of arytenoids.

26.  Glottis (Rima Glottidis).
 It is the elongated space between vocal cords anteriorly, and vocal
processes and base of arytenoids posteriorly
 glottis is about 24 mm in men and 16 mm in women. It is the narrowest part
of laryngeal cavity.
 Anterior two-thirds of glottis is also called phonatory glottis as it is
concerned with phonation
 posterior one-third called respiratory glottis.

27. Spaces of the Larynx
 1. Pre-Epiglottic Space of Boyer.
 2. Paraglottic Space.
 3. Reinke’s Space

28. Pre-Epiglottic Space
 Bound sup by hyo-
epiglottic ligament, ant
by thyrohyoid memb. &
thyroid cartilage and
posteriorly by epiglottis
 Filled with fat and
areolar tissue
 Continuous with para-
glottic space
 Cx of laryngeal surface
of epiglottis readily
spread to PreEpiSpace

29. Paraglottic space.
 It is bounded by the thyroid cartilage
 laterally, conus elasticus inferomedially, the
ventricle and
 quadrangular membrane medially, and mucosa
of pyriform fossa posteriorly.
 It is continuous with pre-epiglottic space.
Growths which invade
 this space can present in the neck through
cricothyroid space

31. Reinke’s Space
 Mucosa over the vocal ligament
loosely attached to ligaments
 Thus there is a submucosal
space along most of the length
of truer VC

32. PAEDIATRIC LARYNX
 1. Infant’s larynx is positioned high in the neck level of glottis being
opposite to C3 or C4 at rest and reaches C1 or C2 during swallowing.
 This high position allows the epiglottis to meet soft palate and make a
nasopharyngeal channel for nasal breathing during suckling.
 2. Laryngeal cartilages are soft and collapse easily. Epiglottis is omega
shaped
 3. Thyroid cartilage in an infant is flat. It also overlaps the cricoid
cartilage and is in turn overlapped by the hyoid bone.
 4. Infant’s larynx is small and conical.
 5. Submucosal tissues of infant’s larynx are comparatively loose and easily
undergo oedematous change with trauma or inflammation leading to
obstruction

33.  Infant’s larynx shows two spurts in growth: first 3 years of life, larynx
grows in width and length
 The second spurt in growth occurs during adolescence when the thyroid
angle develops.
 In childhood, vocal cord is 6 mm in females and 8 mm in males. It
increases to 15–19 mm in adult female and 17–23 in adult male.

34. THANKYOU