The document provides details on the anatomy of the larynx. It discusses the location and structure of the larynx, including the nine cartilages that form its framework, the ligaments that connect the cartilages, and the intrinsic and extrinsic muscles. It describes the three parts of the laryngeal cavity, and covers the nerve and blood supply of the larynx. Key points covered include that the larynx functions in breathing, sound production, and protecting the lungs, and that the narrowest part is the rima glottidis in adults and the cricoid cartilage in children.

1. ANATOMY OF LARYNX
By- Dr.SHALINI

3. Opposite 3rd – 6th cervical vertebrae
(men)
Higher in women and children
Situated at the upper end of trachea
At puberty AP diameter in males
doubles
Surface Anatomy

4. Functions
 Breathing
 Sound Production
 Manipulation of Pitch and Volume
 Protecting Lungs against Food aspiration

5. Laryngeal Cartilages
Paired
Arytenoid
Corniculate
Cuneiform
Unpaired:
Thyroid cartilage
Cricoid cartilage
Epiglottis

6. Thyroid Cartilage
Hyaline Cartilage
Largest
Encloses the
larynx anteriorly
and laterally
Two Laminae
Ossification

7. THYROID CARTILAGE
Shield like , longest cartilage
Meet at midline called Thyroid notch
Fused anterior border – Laryngeal
Prominence (90-120 degrees)
well marked in males-Adam’s apple
Posteriorly, the laminae diverge
Has Superior and Inferior Cornua

8. Cricoid Cartilage
1. Anterior arch
2. Posterior
lamina
3. Articular
facet

9. Cricoid Cartilage
 Hyaline Cartilage, strongest
 Directly below the thyroid cartilage
 Shape: Signet Ring
 Lamina – flat portion
 Only complete annular support -------
of larynx
 Articulates with Inferior cornu of the thyroid
cartilage & arytenoid cartilage

10. EPIGLOTTIS
Thin, leaf-like, elastic
fibrocartilage
Projects upward behind
tongue & hyoid
Superior margin overhangs
laryngeal inlet
Posterior aspect free and
bears a bulge-tubercle

11. EPIGLOTTIS
Anterior aspect-
Upper part free with Covering membranes:
a)Median glosso epiglottic &
b) Lateral pharyngo epiglottic folds
Lower part is attached to
a)hyoid - Hyo epiglottic lig
b)Thyroid.c -Thyroepiglottic lig

12. EPIGLOTTIS
Valleculae:
Common site for impaction of shallow sharp
objects like fish bones

14. PAIRED CARTILAGES
Cuneiform
Corniculate
Arytenoid

15. Arytenoid Cartilage
 Hyaline cartilage
 Smaller in size
 Responsible for opening and closing of the
larynx
 Shape: pyramidal

17. Arytenoid Cartilage
 Anterior
◦ Vocal process
 Lateral
◦ Muscular process
 Articulation
◦ Cricoarytenoid joint at
superolat aspect of lamina
of cricoid.c
17
Arytenoid
Cartilage

18. Corniculate Cartilages
 Fibroelastic ,horn shaped
 Cartilages of Santorini
 Small cartilages above
the arytenoids in
aryepiglottic folds
• Serve to prolong arytenoids
posteromedially

19. Cuneiform Cartilages
 Firboelastic, clubshaped
 Cartilages of Wrisberg
 Elongated pieces of
small yellow elastic
cartilage in the
aryepiglottic folds.
 support the vocal folds
& lateral aspects of the
epiglottis.
.

20. Laryngeal Ligaments
Extrinsic
Thyrohyoid
membrane and
ligaments
Cricothyroid
membrane and
ligaments
Cricotracheal
ligament
Intrinsic
Quadrangular
membrane
Conus elasticus
(cricovocal membrane)
Median cricothyroid
ligament
Vocal Ligament
Thyroepiglottic
ligament

21. 2. Cricothyroid
Membrane
links thyroid to
cricoid;
Median Cricothyroid
Ligament - thickened
midline part
3. Cricotracheal
ligament
links Cricoid to first
tracheal cartilage
LIGAMENTS OF LARYNX
A. Structural ligaments - hold larynx, hyoid, trachea together
1. Thyrohyoid Membrane
links larynx to hyoid;
Median
Thyrohyoid
Ligament
Median
Cricothyroid
Ligament

22. INTRINSIC LIGAMENTS
 Quadrangular membrane
Sub mucosal Layer
Between lat aspect of epiglottis & ary.c on
each side
Contains cuneiform.c
Superior border is in ary epiglottic fold
Inferior border is free & forms vestibular lig

24. INTRINSIC LIGAMENTS
 Crico vocal memb or Conus elasticus
Vibrating lips that arise
from entire upper edge of arch of cricoid.c
Attached ant to laryngeal prominence of
Thyroid.c
post to vocal process of Arytenoid.c
Free upper border-vocal lig
Anteriorly thickens into Crico thyroid lig

25. Upper free
Edges
Deep to
Vocal
Folds
Rima Glottidis -
Opening Between
Vocal ligaments
Conus Elasticus -
Vibrating lips
that arise
from entire upper edge of
arch of cricoid
Attach: ant. to Thyroid,
post. to Arytenoid
Vocal
Ligaments -
INTRINSIC LIGAMENTS

26. Cavity of the Larynx
epiglottis
VESTIBULE - inlet above false
vocal folds
VESTIBULAR (FALSE VOCAL)
FOLDS - overlie vestibular
ligaments
VENTRICLE - area between true
and false vocal folds; lateral
extension is Laryngeal
Sinus
VOCAL (TRUE VOCAL) FOLDS
- overlie vocal ligaments

27. Cavity of the Larynx
Divided into 3
parts:
Vestibule
Ventricle
Subglottic space

28. MUSCLES OF LARYNX
Extrinsic Muscles
Sternohyoid
Thyrohyoid
Omohyoid
Sternothyroid
Geniohyoid
Digastrics
Mylohyoid
Stylohyoid
Intrinsic Muscles
Interarytenoid Muscle
• Transverse
• Oblique
Posterior Cricoarytenoid m.
Lateral cricoarytenoid m.
Thyroarytenoid m.
Cricothyroid m.

29. MUSCLES OF LARYNX
A. Extrinsic muscles (ex. hyoid muscles) – Move whole
larynx as in swallowing
B. Intrinsic Muscles 1) change tension in vocal
ligaments,
changes pitch
2) open & close Rima Glottidis
1) CRICOTHYROID Muscle-
Tenses
Vocal Ligament
Increasing Pitch
Slack Tense

30. MUSCLES OF LARYNX
INTERARYTENOID
(Transverse and
oblique arytenoid) -
Adduct vocal folds
LATERAL CRICO-
ARYTENOID –adduct
vocal folds by internal
R rotation of arytenoids
3) POSTERIOR CRICO-
ARYTENOID – Abducts
vocal fold by ext rot of
arytenoids
Arytenoids
Can rotate/slide

32. MUSCLES OF LARYNX
THYROARYTENOID
MUSCLE
Origin-junction of laminae
of thyroid.c
Insertion-ant lat aspect of
arytenoids
Function-
Relaxes vocal ligaments.

33. NERVE SUPPLY

35. Recurrent Laryngeal Nerves
Right & Left

36. Left Recurrent
Laryngeal Nerve
Course

37. NERVE SUPPLY
SUP. LARYNG. N.
A. Superior Laryngeal N.
divides to -
1. Internal Laryngeal N.
Sensory to Larynx
• Above True Vocal Folds
2. External Laryngeal N.
Motor to Cricothyroid
Int. Laryng. N.
B. Recurrent Laryngeal N.
Ext. Laryng. N.
RECURRENT
LARYNG. N.
- Sensory to Larynx
Below True Vocal Folds
motor to all other
Muscles of Larynx

38. ARTERIAL SUPPLY
Sup. Laryngeal A.
from Sup. Thyroid artery
Inf. Laryngeal A.
from Inf. Thyroid artery

39. VENOUS DRAINAGE
•Upper Larynx
Superior laryngeal vein
Superior thyroid vein
Internal jugular vein
•Lower Larynx
Inferior laryngeal vein
Inferior thyroid vein
Innominate vein

40. LYMPHATIC DRAINAGE
Superior Deep
Cervical Nodes
(Larynx above true vocal folds)
Inferior Deep
Cervical Nodes
(Larynx below true vocal folds)

41. Post.
Ant.
Epiglottis
Tongue Vocal Folds
(true vocal
folds)
LARYNGOSCOPE VIEW
vocal folds
adducted when
talking or singing
Vestibular Folds
(false vocal folds)

42. Normal Vocal Cord Positions

43. Laryngoscopy Grading
 Most Popular grading system
is
Cormack and Lehane
Grade 1
All Structures Visible
Grade 2
Only posterior part of glottis
is visible
Grade3
Only epiglottis is seen
Grade4
No Recognizable Structures

44. Microscopic Feature Of Larynx
 Mucosa is lined by ciliated columnar
epithelium with
scattered mucus secreting goblet cells
 Stratified Squamous epithelium
 Over Vocal Cords
 At the entrance to larynx

45. Paediatric Larynx
Infants – smaller, narrow lumen, funnel
shaped
In newborn- at the level of C2-C3v
Cartilages softer & collapse easily
Narrowest Portion: Cricoid cartilage
in infant

46. Paediatric Laryngoscopic View

47. Paediatric Larynx
 Epiglottis: Longer, narrower and stiffer in
infant
 Aryepiglottic folds closer to midline
in infant
 Vocal folds: Anterior angle with respect
to perpendicular axis of larynx

48. Cord Palsies
 1.Unilateral Pure Abductor Palsy
 a)On Phonation: Cords meet in midline because
adductor fibers on damaged side are still active
 b)On Inspiration: Injured side cord remains in
same position
 Normal side cord moves into full abduction

49. 2)Unilateral abductor and adductor palsy:
Damaged cord lies slightly in abduction
a)On Phonation:
 Normal side cord crosses the midline in an
attempt to meet its opposite cord

50. b)On Inspiration:
 Normal side cord moves into full
abduction

51. 3)BiLateral damage to Recurrent Laryngeal.N
a)Mild trauma on both sides
• Bilateral Abductor Paralysis
• Adductor fibres are still functioning
• So vocal cords lie near midline
• Airway is greatly reduced
• Patient shows severe respiratory obstruction

52. b)Severe trauma on both sides:
• Loss of both abductors and adductors
• Both vocal cords lie in midposition
• Fair sized lumen between them
• Airway is fairly adequate with
Marked Respiratory effort
• Cords sucked in with each inspiration

53. 4)Bilateral Palsy of recurrent laryngeal.N with
palsy of external branch of superior laryngeal.N
 Paralysis of crico thyroid muscles leads to loss
of tension of the cords and reduced antero-
posterior diameter of glottis

54. Superior Laryngeal Nerve Block
Tracheal
Injection
Pharyngeal Gargle

55. SUPERIOR LARYNGEAL N BLOCK
 Locate the hyoid bone
 1cm below each greater cornu (where the
internal branch of the superior laryngeal
nerve penetrates the thyrohyoid
membrane)
 Infiltrate 3ml 2% lignocaine
 Feel a ‘pop’ as the needle penetrates the
membrane

56. TRANSTRACHEAL BLOCK
 Extend the neck.
 Identify the cricothyroid membrane.
 Inject 4ml 4% lignocaine at the end of
inspiration.
 A resultant cough will distribute the
anaesthetic.

57. Summary
 Larynx is a Vital Organ for Breathing, Speech
and Protection of Lungs.
 Formed by Nine Cartilages, Ligaments and Muscles.
 The Narrowest part in Adults is Rima Glottidis.
 The Narrowest part in Children is Cricoid Cartilage.
 Nerve supply is by Vagus Nerve. (Sup & Rec L N)
 Blood Supply is by the branches of Ext Carotid A.

58. THANK YOU