The larynx extends from the laryngeal inlet to the inferior border of the cricoid cartilage. There are 9 cartilages that make up the framework of the larynx, connected by joints, ligaments, and membranes. The larynx contains 8 muscles that move the cartilages and open/close the laryngeal inlet and vocal cords. The larynx develops from the endoderm, branchial arches, and surrounding mesenchyme during embryological development. The infant larynx differs from the adult larynx in its higher position, softer cartilages, and funnel shape.

1. ANATOMYOFLARYNX
DR.PRASANNA DATTA ,

2. Thelarynx extends from the laryngeal inletto
the inferior border of the cricoid cartilage.

3. • Larynx lies opposite the third tosixth cervical
vertebrae, being alittle higher
in women thanin
men.
•Theinfantile larynx
is proportionally
smaller and is more
funnel shaped.

4. Measurements
• Until puberty there is little difference b/w male &
female larynx.
• After puberty:- Male larynxundergoes
considerable increase
In Males In Females
Length 44 mm 36 mm
Transversediameter 43 mm 41mm
A-Pdiameter 36 mm 26 mm
Circumference 136 mm 112 mm

5. Theframework of the larynx
• Hyoid bone
• 9 Cartilages: –
Connected by
• Joints
• Ligaments
• Membranes
• Moved by
• 8 Muscles(Intrinsic)
• Cavity – Mucous membrane

6. Cartilages
• 3 Paired
• Arytenoid
• Corniculate
• Cuneiform
• 3 Unpaired
• Thyroid
• Cricoid
• Epiglottis

7. HYOIDBONE
U-shapedbone

8. ThyroidCartilage
• Shield shaped, open posteriorly, angulated
anteriorly
• Largest cartilage of larynx
• Protect larynx
• Provide an attachment to vocalcords

13. • Thelateral thyrohyoid ligament connectsthe
tip of the superior cornua of the thyroid
cartilage to the posterior ends of the greater
cornua of thehyoid.
• Theligaments often contain asmall nodule of
cartilage, the cartilagotriticea

15. Onthe external surface of eachlamina, anoblique
line
curves downwards and forwards from thesuperior
thyroid tubercle, situated just in front of the root of
the superior horn, to the inferior thyroid tubercle
on the lower border of the lamina.
Thisline marks the attachment ofthe
 Thyrohyoid,
Sternothyroid
Inferior constrictor muscles.

18. • Avertical ridge in the midline of thelamina
givesattachment to
longitudinal muscleof the oesophagus
and produces ashallow concavity on each
side for the origin ofthe
posterior cricoarytenoidmuscle.
• Theentire inner surface of the cricoid
cartilage is lined with mucousmembrane.

19. Of laryngealinlet

21. • Hyoepiglottic ligament divides epiglottis into
– Suprahyoid Epiglottis
– Infrahyoid Epiglottis

22. Lateral

23. Pre-epiglottic spaceof Boyer
Anterior surface of infrahyoid epiglottis is
separated from thyrohyoid membrane and
thyroid cartilage by fat filled pre-epiglottic
space.
Pre-epiglottic space invaded by carcinoma of
supraglottic larynx and the base of tongue.

25. Boundaries
Anterior: Upper part of thyroid cartilageand
thyrohyoid membrane.
Superior: Hyoepiglottic ligament.
Posterior: Infrahyoid epiglottis.
Inferior: Thyroepiglottic ligament.
Communication: Laterally itis continuous with
paraglottic space.

29. • Thyroid
• Cricoid
• Arytenoids
(Exceptits tip)
Hyaline Cartilage
May ossify after 20
yrs (Male)(T→C→A)
complete by 65yrs.
Fibroelastic
Theydo not ossify
• Epiglottis
• Corniculate
• Cuneiform
• Tip ofArytenoid

30. Arytenoid Gliding-medially & Laterally
closing and opening the post part of
glottis

31. MEMBRANES&LIGAMENTS
Extrinsic Intrinsic
Thyrohyoid Quadrangular membrane
Cricotracheal vestibular ligament
Hyoepiglottic Crico-vocal membrane&
vocal ligament

33. Thyrohyoidmembrane
median thyrohyoid ligament 2lateral thyrohyoid ligament
superior cornua of the
thyroid cartilage to the
posterior ends of the
greater cornua of the
hyoid. Small nodule of
cartilage, CARTILAGO
TRITICEA

34. Epiglottic
cartilage to
the body
of hyoid
bone
Lower
border of
cricoid
cartilage
to 1st
tracheal
ring

35. Intrinsic
•Part of Fibro-elasticMembrane
which lies beneaththe
mucous membrane of the
larynx.
•Thefibro-elastic membrane
is divided into anupper
and lower part bythe
laryngeal ventricle.

36. Cricovocal membrane

37. & Cricothyroidmembrane

40. Quadrangular membrane

41. Laryngeal Cavity
•From Inlet
of Larynx to
Lower border
of Cricoid
Cartilage
(Lower border
Of 6th cervical
vertebra)

43. Vestibule:
• This region lies between the laryngeal inletand
vestibular folds.
Boundaries:
• Anterior wall:
– Posterior surfaceof
epiglottis.
• Lateralsides:
-Aryepiglottic folds.
• Posterior wall:
-Arytenoids.

44. contains vestibular
ligament, afew fibres
of thyroarytenoideus
muscle and mucous
glands.
(true vocalcords).

45. Broyle’sligament

46. Ventricle (Sinus of larynx) /sinus of
Morgagni:
• This deep elliptical spacelies
between
vestibular
and vocal folds.

47. • Thesubmucosaof the ventricle
contains numerous seromucinous
glands.
• Thesecretions produced by these
exocrine glands provide both
mechanical and immune (lysozyme)
protection for the vocalfolds.

48. Laryngeal saccule/ Sacculeof Hilton
• At the anterior endof
the ventricle is a
diverticulum
• Thesaccule (of Hilton) is
lined with mucous
glands, which are
thought to lubricate the
vocal folds

49. • Abnormal dilatation of the saccule results
in an air-filled laryngocele that should be
distinguished
from amucoceleof the saccule(saccular
cyst),which lacks free communication with the
ventricle not airfilled

50. CTshowslaryngocele

52. • most of the laryngeal foreignbodies are seen
in supraglotticregionlying above the vocal
cords.
• Subglotticregion(Infraglottic larynx):
• Extendsfrom below the vocal cords tolower
border of cricoidcartilage.

53. Glottis (Rimaglottidis):
• This narrowest part of an adultlaryngeal
cavity liesbetween
vocal cords and
arytenoids of the
two sides.

54. Anteroposterior length of glottisis
men (24 mm)
women (16mm).

55. Pyriform fossa

56. SPACESOFTHELARYNX
Pre-epiglottic space ofBoyer:

57. Pre-epiglottic space ofBoyer
• Pre-epiglottic space can be invaded by
carcinoma of supraglottic larynx and the base
of tongue.

58. Paraglottic space lTuckersSpace:
It communicates withpre-epiglottic
space (Anteriorsuperioly)
•Boundaries:
Laterally:
Thyroid cartilage and
cricothyroid membrane.
Medial:
Conus elasticus,
Ventricle and quadrangular
membrane.
Posterior:
Anterior mucosa ofpyriform
fossa.

59. Paraglottic space lTuckersSpace:
• Growths invading paraglottic spacedestroy
cricothyroid Membrane
• Ventricle tumors -> spread transglottically
• Vocal cord tumors involving thyroarytenoid
muscle -> subglottic and extralaryngeal region.
• Lateral supraglottic tumors cantravel to
subglottic region ->the inner surface of
thyroid.
• Pyriformfossa tumor ->into endolarynx andfix
vocal folds

60. Reinke’sspace
• This potential space has scantysubepithelial
connective tissues and lies under the
epithelium of vocalcords.
• It is boundedby–
Above and below:Arcuatelines.
Anterior: Anterior commissure.
Posterior: Vocal process ofarytenoids.

61. Layered structure of the vocalfold
• Lamina Propria- 3Layers
1. Superficial-fibrous Substance(Reinkesspace)
2. Intermediate –elastic
3. Deep– Collagen fibres
VOCALLIGAMENT formed
By Intermediate and deep
layer
Body contain Vocalismuscle

62. MUSCLESOFLARYNX
• There are two types of laryngealmuscles
intrinsic (connecting laryngeal cartilages
to eachother)
extrinsic(connecting larynx to the
surrounding structures).

63. Intrinsic muscles
They are further divided intotwo:
1) muscles acting on vocalcords
2) muscles acting on laryngealinlet.
Vocal cords
Abductors: Posterior cricoarytenoid
Adductors: Lateralcricoarytenoid
Interarytenoid (transverse andoblique
arytenoids)
Thyroarytenoid (external part)
Tensors:
Relaxers:
Cricothyroid
Vocalis & Thyroarytenoid internalpart

64. Cricothyroid
Action: lengthensvocal
folds(tensor)
• Nerve(motor supply):
Supplied by the
external laryngeal
nerve,a branch of
superior laryngeal
nerve.

65. Posterior cricoarytenoid
• Action: Abduction of
Vocal Cord

67. Interarytenoid
• Transverse
interarytenoid
Action : Adductsvocal
folds
• oblique
interarytenoids
Action : Closeslaryngeal
inlet

68. Thyroarytenoid –
Internal part (Vocalis)
• Action : Shortens
vocal folds &
thickness

69. Relaxersof VC:Vocalis and
thyroarytenoid

70. Laryngeal inlet
• Openers:
Thyroepiglottic
(part ofthyroarytenoid)
• Closers:
- Interarytenoid
(oblique part)
-Aryepiglottic (posterior
oblique part of
interarytenoid)

71. (1) digastric, (2)stylohoid,
(3) mylohyoid, (4) sternocleidomastoid, (5) thyroidhyoid,
(6)sternothyroid, (7) cricothyroid, (8)
sternohyoid and (9) omohyoid
Omohyoid

73. Extrinsic muscles:
• Secondary elevators: They are attached tothe
hyoid bone
Mylohyoid (main)
Digastrics
Stylohyoid
Geniohyoid.

76. Lymphatic Drainage

77. EMBRYOLOGICALDEVELOPMENT
Structure Source
laryngeal mucosa Endoderm of cephalic part
of foregut
laryngeal cartilages mesenchyme
Epiglottis Hypobranchial eminence
Upper part of body ofhyoid bone
Lessercornua of hyoid bone
Stylohyoid ligament
2nd branchial arch
Lower part of body of hyoidbone
and greater cornua
3rd branchial arch

78. 4th branchialUpper part of thyroidcartilage
arch
arch
lower part of thyroidcartilage,
th
cricoid, corniculate, and cuneiform 6
cartilages
Intrinsic muscles of larynx 6th branchialArch

79. Infant LarynxVSAdultLarynx
Infant Larynx Adult Larynx
higher in the neck
Vocalcords lie at C3/C4level
During swallowing go up to C1/C2level.
Low
Vocal cords lie at C5level.
Laryngeal cartilages are soft and
collapse easily.
Cartilage undergo ossification
Epiglottis: omegashaped& Floppy Firmand flatter
Arytenoids: large
Thyroid:flat.
Cricoid: Thediameter of cricoidissmaller
than glottis
subglottisis the narrowest portion
Glottisis the narrowest portion
Cricothyroid and thyrohyoid spaces:They
are very narrow

80. Infant Larynx Adult Larynx
Size:smaller and hasanarrower lumen. Wider lumen
Shape:It is conicalandfunnel-shaped columnshaped
Submucosal tissue: It is thick andloose
and becomes easily
edematous in response to traumaor
inflammation

81. Infant Adult

82. Adult Larynx Infant Larynx

83. Applied anatomy