Anatomy of Larynx

1. Dr. Padmaja Pallavi Pandey

2.  Extend from laryngeal inlet upto lower border of
cricoid cartilage.
 Opposite to 3rd
– 6th
cervical vertibrae.
 Narrowest part – junction of subglottic larynx
with trachea.
 AP diameter- 36mm in male
- 26mm in female

3.  Specialized organ at the inlet of air passage.
 Protective sphincter at the air passage
 Regulates passage of air in inspiration and
expiration.
 To stop food/liquid from entering the lungs
 Opens & closes during swallowing, coughing &
sneezing
 To Bear Down
 While Expelling
 Childbirth
 While Lifting
 PHONATION
 SPEECH

5. Laryngeal generation
of voice

6. Larynx

7.  Respiratory system – outgrowth of primitive pharynx
 3 weeks - Hypobrancial eminence – gives rise to furcula
-> epiglottis
 3.5 weeks – laryngotracheal groove, ventral aspect of
foregut
 5th
week – Arytenoid masses
 5-7 weeks – laryngeal lumen is obliterated
 9 weeks – oval shape lumen reestablished
 8-10 weeks – Formation of true and false vocal cords
 12th
week – ventricles
 Laryngeal muscles – derivatives of mesoderm of 4th
and
5th
arches (CN X)

8.  Development of the larynx can be divided into
prenatal and postnatal stages.
 At birth, the larynx is located high in the neck
between the C1 and C4 vertebrae, allowing
concurrent breathing or vocalization and
deglutition.
 By age 2 years, the larynx descends inferiorly.
 By age 6 years, it reaches the adult position
between C4 and C7 vertebrae.This new position
provides a greater range of phonation (because of
the wider supraglottic pharynx) at the expense of
losing this separation of function, i.e., deglutition
and breathing.

9.  The larynx develops from the endodermal lining
and the adjacent mesenchyme of the foregut
between the fourth and sixth branchial arches.
 At 20 days' gestation, the foregut is first
identifiable with a ventral laryngotracheal groove.
It continues to deepen until its lateral edges fuse.
 Trachea becomes separated from the esophagus by
the tracheoesophageal septum with a persistent
slit like opening into the pharynx.
 This fusion occurs in the caudal-to-cranial
direction, and incomplete fusion results in
development of persistent communication
between the larynx or trachea and the esophagus

10.  The larynx grows rapidly during the first 3
years of life, while the arytenoids remain
approximately the same size.
 Beginning at age 18-24 months, the larynx
descends in the neck to achieve its final
position at vertebrae C4-C7 by age 6 years.
 The larynx elongates as the hyoid, thyroid,
and cricoid cartilages separate from each
other
 The cricoid cartilage continues to develop
during the first decade of life, gradually
changing from a funnel shape to a wider
adult lumen; therefore, it is no longer the
narrowest portion of the upper airway.

11. Child’s Larynx
1)Situated high up
against C3-C5
Vertebrae
2)Is of equal size in
both male & female
Adult’s Larynx
1)Situated against C4-
C6 Vertebrae
2)Length-In male,it is
44mm & in female,it
is 36mm
Transverse-In male, it is
43mm & in female,it
is 41mm
Anteropost-In male,it is
36mm & in female,it
is 26mm.

12. 3)Is funnel shaped
(narrow subglottis)
4)Cartilages are softer
5)Epiglottis is
narrower,longer,
stiffer & folded
with more of
submucosal space
6)Proportionately
smaller larynx.
7)Cricoid cartilage is
the narrowest
portion
3)Glottis is the
narrowest part.
4)Cartilages are not
softer
5)Epiglottis is broader
& shorter.
6)Longer larynx.
7)Vocal folds is the
narrowest portion

13. 8)Aryepiglottic folds
lies closer to the
midline.
9)Vocal folds form an
anterior angle with
respect to
perpendicular axis of
Larynx.
10)Pliable laryngeal
cartilage.
11)Mucosa is more
vulnerable to
trauma.
8)Aryepiglottic folds
lies away from the
midline.

14.  Unpaired cartilages
Epiglottis
Thyroid cartilage
Cricoid
 Paired cartilages
Arytenoid
Corniculate
Cuneiform
All cartilages are
hyaline except the
epiglottis (elastic)

18.  The framework of the larynx is made up of cartilages.
 These cartilages are connected by joints, membranes
& ligaments.
 Moved by muscles.
 Lined by mucous membranes.

19.  The Laryngeal
cartilage are Nine
 3 single & 3 Paired
 Single:
 Thyroid
 Cricoid
 Epiglottis.
 Paired:
 Arytenoids
 Corniculate
 Cuneiform.

20.  It is the largest of the laryngeal cartilage
 Shield shaped, open posteriorly, angulated anteriorly
 The angle between 2 laminae is 90 in male & 120 in
female
 Angulation more acute in males
 Formed of 2 laminae, each has superior & inferior
horn which fuses in midline.

21.  Its function is to shield larynx from injury and
provide an attachment to vocal cords
 Encloses the larynx anteriorly and laterally

24.  Connection of the
thyroid cartilage:
 Superior: To hyoid
bone by thyrohyoid
membrane.
 Inferior: To cricoid
cartilage by the
cricothyroid joint &
cricothyroid
membrane

25.  Signet ring shaped
 Hyaline.
 Stronger than thyroid
cartilage.
 Lamina-a flat portion with
2 to 3 cm from above
downwards, considerably
broader than anterior arch
& wide posterior lamina.
 Only cartilage forming
complete ring
 Directly below the thyroid
cartilage.

27.  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.
Connected superiorly to thyroid cartilage by
cricothyroid joint and cricothyroid membrane.
Only complete annular support of the larynx
 Articulates with Inferior cornu of the thyroid
cartilage

28.  Thin leaf shaped fibro-
cartilage, situated in midline.
 Lies behind the root of the
tongue.
 Upper free end broad &
rounded, projects up behind
base of tongue.
 Connected by its stalk to the
back of the thyroid cartilage.
 Narrow base called pitiole.
 This attachment forms lower
limit of pre-epiglottis space.

29.  Half of epiglottis
projects above hyoid
 This part has a laryngeal
and lingual surfaces
 Its sides are connected
to the arytenoid
cartilage by aryepiglottic
fold
 Its upper end is free. But
its mucous membrane is
connected to the back of
tongue by 3
glossoepiglottic folds 1
median & 2 lateral
 Infrahyoid portion has no
free anterior surface

30.  Forms posterior wall of PES
 Epiglottic cartilage
contains many pits filled
with mucous glands
 Little barrier between
infrahyoid portion and PES
 Attatched anteriorly to
hyoid bone by hyoepiglottic
ligament and inferiorly to
thyroid cartilage by
thyroepiglottic ligament
 Hyoepiglottic ligament
divide it into suprahyoid &
infrahyoid epiglottis.

31.  Paired hyaline cartilages,
smaller in size & pyramidal in
shape.
 Its base sits on the superior
surface of the cricoid lamina
 Has 2 process:-
1)Muscular process-Directed
laterally & gives attachment
to 3 muscles:-
# Posterior cricoarytenoid
# Lateral Cricoarytenoid
# Thyroarytenoid.

32. 2)Vocal process-Anterior angle elongated into vocal
process which receives insertion of vocal ligament,
which directed forward and gives attachment to the
vocal ligament.
 Shaped like a 3- sided pyramid
 Apex: directed superiorly, supports the corniculate
cartilage.
 Responsible for opening and closing of the larynx
 2 fossa presents on anterolateral surface-upper and
lower triangular fossa.
(1)Upper triangular fossa give attachment to vestibular
ligament.
(2)Lower fossa to vocalis and lat.cricoarytenoid muscle
 Posterior surface is covered by transverse arytenoid
muscle

35. The arytenoid cartilages, two pyramid shaped cartilages rest on
the cricoid at the cricoarytenoid joints and move in two distinct
ways:
1.) To pivot (rocking) the posterior ends of the arytenoids away
from each other, adducting the anterior ends or the reverse so the
anterior ends abduct, and…
2.) Sliding the arytenoids on an anterior-posterior path.
Since the vocal folds are attached to the anterior ends of these
cartilages (at the vocal process) any movement in them will
change the folds’ shape, tension and relationship to each other
thereby affecting phonation.

37. 1. Epiglottis
2. Arytenoid cartilage
3. Corniculate cartilage
4. Aryepiglottic fold

38.  Fibroelastic
 Cartilages of Santorini
 Situated in the aryepiglottic folds
 Articulate with apex of arytenoid
cartilage

39.  Firboelastic cartilages
 Cartilages of Wrisberg
 Elongated pieces of small yellow elastic
cartilage in the aryepiglottic folds

40.  Cartilago triticea
 Small elastic cartilage in the lateral
thyrohyoid ligament.

41.  SUPRAGLOTTIS
 GLOTTIS
 SUBGLOTTIS

42.  Consists of:-
1)Ventricles
2)Suprahyoid epiglottis(Lingual & Laryngeal surfaces)
3)False vocal cords
4)Laryngeal surface of epiglottis
5)Aryepiglottic folds
6)Mucosal expanse
7)Arytenoids
8)Infrahyoid epiglottis
 Posterior tapering shape reduces area of mucosa in
posterior region
 So majority of SG tumors are epiglottic

44.  Consists of:-
1)True Vocal cords
2)Anterior commissure
3)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”

45. # Consists of a mobile upper and fixed lower part
# Extends from 5-10mm below the vocal cord upto
lower inf border of cricoid cartilage.

46. TRUE VOCAL CORD
1)Glottis contains true vocal
cord.
2)Protection of lower
respiratory tract.
3)Tissue can actually
regenerate, when
removed.
4)Encloses vocal ligament &
a major part of the Vocalis
muscle.
FALSE VOCAL CORD
1)Supraglottis contains
false vocal cord.
2)Forms boundaries of
the Quadrangular
membrane of Intrinsic
ligaments.
3)Tissue is thicker.
4)Also known as
VENTRICULAR FOLDS or
VESTIBULAR FOLDS or
VENTRICULAR BANDS.

47. TRUE VOCAL CORD
5)Folds of mucous membrane in
the larynx,mainly the inferior
pair forms True vocal cord.
6)Used in general speaking or can
be heard when listening to
most songs(non-metal).
7)Used most often when talking
& Voice production.
8)The pitch vary from person to
person. Female have high
pitched true vocal cord than
those of male.
9)BOUNDARIES:-
Ant:- Angle of the Thyroid
cartilage.
Post:- Vocal processes of the
Arytenoid cartilages
FALSE VOCAL CORD
5)Folds of mucous membrane in
the larynx,mainly the superior
pair forms False vocal cord.
6)Used in musical song,mostly in
metal(Deep growl or
screaming)or throat singing.
7)Can also used to produce a
low,bass like pitch.
8)BOUNDARIES:-
Ant:- Angle of the Thyroid cartilage
Post:- Bodies of the Arytenoid
Cartilages.

48.  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.

49. 2 Major groups
A)EXTRINSIC MUSCLE: ( move the whole
larynx)
Elevators: Digastric,stylohyoid, mylohyoid,
geniohyoid, stylopharyngeus,
salpingopharyngeus & palatopharyngeus.
Depressors: Sternothyroid, sternohyoid &
omohyoid.
Constrictor:
Pharyngeal:

50. B)INTRINSIC MUSCLE( movement within
larynx)
 Control of laryngeal inlet
 Control of rima glottidis
 Control of length & tension of vocal cords
 All intrinsic muscles lie inside the larynxAll intrinsic muscles lie inside the larynx
cricothyroidcricothyroid

51.  SuprahyoidsSuprahyoids – Attach to points above the
Hyoid (Jaw, Skull and Tongue),when they
contract,they raise or elevate the Larynx.eg
Swallowing
 InfrahyoidsInfrahyoids – Attach to points below the Hyoid
(one connects to the thyroid, however the
others connect to the sternum and the
scapula),when they contract they lower or
depress the Larynx.

55.  AdductorsAdductors – vocal folds are together
 AbductorsAbductors – vocal folds apart
 Tensors -Tensors - Stiffen
 Relaxors -Relaxors - Relax

56.  Lateral Cricoarytenoids
 Cricothyroid
 Interarytenoids
Transverse Arytenoids
Oblique Arytenoids
Thyroarytenoid

62.  Origin: Anterior part of arch of cricoid
 Insertion: Inferior border & inf. Horn of thyroid
 Causes flexion at cricothyroid joint
 Lengthens & tightens the vocal ligament
 Nerve supply: External laryngeal nerve of
superior laryngeal of vagus.

63.  Posterior
cricoarytenoids
 Lateral cricoarytenoid
 Interarytenoid
muscles:
Transverse &
Oblique
 Thyroarytenoid muscle
 Aryepiglottic muscles

67.  Posterior Cricoarytenoids

69.  External Thyroarytenoid – Relaxor, shortensRelaxor, shortens
and adductsand adducts
 Internal Thyroarytenoid – Tensor, shortensTensor, shortens
and stiffensand stiffens
 Cricothyroid Muscles – Tensor, lengthensTensor, lengthens
and stiffensand stiffens
Pitch is determined by Relaxors and TensorsPitch is determined by Relaxors and Tensors

71. MUSCLE
1)Cricothyroid
2)Posterior
Cricoarytenoid
3)Lateral
Cricoarytenoid
4)Interarytenoideus
5)Vocalis
ACTION
Tensor,Adductor
Abductor
Adductor
Adductor
Adductor

72.  Muscle
External Thyroarytenoids –
inserts into the muscular process on the Arytenoids and theinserts into the muscular process on the Arytenoids and the
Thyroid notch (shorten and adduct)Thyroid notch (shorten and adduct)
Internal Thyroarytenoids – insertsinserts
into the vocal process on the Arytenoids and the Thyroid Notchinto the vocal process on the Arytenoids and the Thyroid Notch
(shortens and stiffens), act antagonistically to the Cricothyroids(shortens and stiffens), act antagonistically to the Cricothyroids
 Membrane

73.  False Vocal Folds – Ventricular folds
 Laryngeal Ventricle
 Lamina propria (mucosal cover of the
vocalis muscle) – can vibrate independently of the
vocalis muscle

75.  MOTOR
All muscles of the larynx are supplied by
the recurrent laryngeal nerve EXCEPT
Cricothyroid - supplied by external laryngeal
branch of superior laryngeal nerve.
 SENSORY & SECRETOMOTOR
Above Vocal Cords: Internal laryngeal
Below Vocal Cords: Recurrent
laryngeal

76.  Superior Laryngeal Nerve -It
leaves the vagus nerve high in
the neck
 Internal -It provides sensation of
the glottis and supraglottis,
which includes the pharynx,
underside of the epiglottis and
the larynx above the cords.
 External -It supplies motor
function to the cricothyroid
muscle which tenses the vocal
cords and could cause
laryngopasm.

77.  Recurrent Laryngeal Nerve -It
provides sensation to the
subglottic area which includes
the larynx below the vocal cords
and upper esophagus. It provides
motor function to the intrinsic
muscles of the larynx.
 It branches from the vagus in the
mediastinum and turns back up
into the neck. On the right, it
travels inferior to the subclavian
and loops up, and on the left it
travel inferior to the aorta and
loops up.

78.  The interior of the larynx
 It is divided into 3 parts:
 1- vestibule: between
laryngeal inlet & vestibular
fold.
 2- Ventricle: a depression
extending laterally between
vestibular & vocal folds.
 3- Infraglottic cavity: lies
between the vocal fold &
lower border of cricoid
cartilage.
 It is continuous with the
trachea inferiorly.

79.  Superior laryngeal artery –
branch of superior thyroid artery
 Inferior laryngeal artery –
branch of inferior thyroid artery
 Veins accompany the arteries

81.  1) Pre-epiglottic space
 2) Paraglottic space
 3) Reinke’s space
 4) Anterior subglottic wedge

82.  Wedge shape space
 Boundaries:-
Superiorly: hyo-epiglottic ligament
Anteriorly: thyrohyoid memb &
thyroid cartilage
Posteriorly: Infrahyoid Epiglottis
Inferiorly: Thyroepiglottic ligament
 Filled with fat and areolar tissue
 Continuous with para-glottic
space
 Carcinoma of laryngeal surface of
epiglottis readily spread to Pre
Epiglottic Space.

83.  Boundaries :-
Laterally- thyroid cartilage
Medially- conus elasticus
- quadrangular membrane
Posteriorly- pyriform fossa

84.  Space under epithelium of
vocal cords
 Mucosa over the vocal
ligament loosely attached to
ligaments
 Thus there is a submucosal
space along most of the length
of true VC
 Boundaries :-
Above and below-arcuate lines
Anteriorly– ant. Commissure
Posteriorly- vocal process of
arytenoid

85.  1)EXTRINSIC LIGAMENT:-
# Thyrohyoid membrane & ligament.
# Cricothyroid membrane & ligament.
# Cricotracheal ligament
 2)INTRINSIC LIGAMENT:-
# Elastic membrane
# Quadrangular membrane
# Conus elasticus (cricovocal membrane+cricothyroid
membrane+vocal ligament)
# Median cricothyroid ligament
# Vocal Ligament
# Thyroepiglottic ligament

86.  THYROHYOID MEMBRANE
pierced on each side by:
1. Superior laryngeal vessels
2. Internal branch of superior laryngeal nerve
Median thyrohyoid ligament
– thickened median portion
Lateral thyrohyoid ligament
– thickened posterior border
- where cartilago triticea is often found
 CRICOTHYROID MEMBRANE & LIGAMENTS
May be pierced for emergency tracheostomy (cricothyrotomy)
 CRICOTRACHEAL LIGAMENT
Attaches the cricoid cartilage to the first attached ring

87. ELASTIC MEMBRANE
 Divided into upper and lower parts by the ventricle of
the larynx
 lies beneath the laryngeal mucosa, Fibrous
framework of the larynx
QUADRANGULAR MEMBRANE
 Upper part of the elastic membrane
 Boundaries:- Epiglottis , arytenoid, corniculate cartilage, false cord
 Forms part of wall between upper pyriform sinus and laryngeal
vestibule
CONUS ELASTICUS (CRICOVOCAL MEMBRANE)
 Lower part of elastic membrane
 Composed mainly of yellow elastic tissue

88.  Boundaries
Inferior: superior border of cricoid cartilage
Superoanterior: deep surface of angle thyroid cartilage
Superoposterior: vocal process of arytenoid cartilage
MEDIAN CRICOTHYROID LIGAMENT
 Thickened anteior part
VOCAL LIGAMENT
 free upper edge
 the thread like collagenous fibers of the deep layer
of the lamina propria
 Interconnects the thyroid, cricoid and arytenoids
cartilages
THYROEPIGLOTTIC LIGAMENT

90.  Divided into 3 parts:
1) Vestibule
2) Ventricle
3) Subglottic space
VESTIBULE:-
 Extends from laryngeal inlet to vestibular folds
 Boundaries:-
 Anterior: posterior surface of epiglottis
 Posterior: interval between arytenoid cartilages
 Lateral: inner surface of aryepiglottic folds and
upper surfaces of the false cord

91. VENTRICLE:-
 Deep eliptical space between vocal cords and
vestibular fold.
 Saccule – conical pouch at anterior part
Rima glottidis:-
Elongated space between vocal cords anteriorly and
vocal processes and base of arytenoid posteriorly

92. CRICOTHYROID JOINT
 Between inferior cornu of the thyroid cartilage
and facet on the cricoid cartilage at the junction
of the arch and lamina
 Two movements:
1) Rotation
2) Gliding
CRICOARYTENOID JOINT
 Base of the arytenoid cartilage and the facet on the
upper border of the lamina of the cricoid cartilage
 Two movements:
1) Rotation
2) Gliding

93. THANK YOU