The document provides information on the anatomy of the larynx. It discusses the larynx's location and functions. It describes differences between infant and adult larynxes. It also details the cartilages, joints, membranes, muscles, blood supply, nerve supply, and development of the larynx. Key points include that the larynx contains thyroid, cricoid, and various paired and unpaired cartilages which form joints. It also lists the intrinsic and extrinsic muscles that control vocal fold movement and laryngeal functions.

1. Dr.Jayashree.S
Junior Resident
Dept of Oral Pathology &Microbiology
GDC Trivandrum

3. Introduction
Sphincter of the LRT
Air passage
Organ of Phonation

4. Location
 Adult male : Opposite C 3-6
 Children : Opposite C 1-4

5. Neonetal

6. Differences between adult & infant larynx
1. Size- smaller in infants
2. Shape-funnel shaped in infants ,
cylindrical in adults
3. Softness-laryngeal cartilages are softer in infants
4. Superiorly placed in infants
5. Straighter and less oblique than in adults
6. Sensitivity is greater in infants more prone to spasm
7. Sub glottis is very narrow ,even a small swelling can lead to airway
obstruction in infants

7. Dimensions
Male
(mm)
Female
(mm)
Vertical 44 36
Transverse 43 41
AP 36 26
According to Sappey the average measurements of the adult
larynx are as follows:

8. General principles of development
The development of the larynx - prenatal and postnatal stages.
At birth - larynx is located high in the neck b/w C1 and C4 vertebrae,
allowing concurrent breathing or vocalization and deglutition.
At 2 years - larynx descends inferiorly;
At 6 years - 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. Laryngeal frame work consists of :
 Cartilages
 Joints
 Ligaments
 Membranes
 Muscles
 Mucous membrane
 Hyoid bone

10. 1.CARTILAGES OF LARYNX
 3 paired
 3 unpaired
 Paired :
 Arytenoid
 Corniculate
 cunieform
 Unpaired:
 Thyroid
 Cricoid
 Epiglottic

13.  Pyramidal
 Apex – Corniculate
 Base –
Ant –Vocal process
Lat – Muscular process
Arytenoid cartilage

15. Muscles attached
 Ant aspect- lateral cricoarytenoid
 Post aspect-post cricoaytenoid
 Across two arytenoid cartilage- transverse arytenoid
 b/w base and apex-oblique arytenoid

16. Conical
Apex of arytenoid
Lie in Ary epiglottic fold
Corniculate cartilage

17. Rod shaped
Anterior to corniculate
Cuneiform cartilage

19. Thyroid cartilage
V shaped in C.S.
 Quadrilateral laminae
 90o in male ; 120o in female
 Oblique line : Thyrohyoid & Inf Constrictor

20. Laryngeal protuberance
Thyroid notch

21. Cricoid cartilage
 Ring shaped
 Lamina – Posterior articulates with
Arytenoid
 Arch – Anterior articulates with
Thyroid cartilage

22. Epiglottic cartilage
 Leaf shaped
 Behind the hyoid and
tongue

23. Stalk  Angle between
the laminae of thyroid
cartilage

24.  R/L margins –
Ary-epiglottic fold
 Ant surface :
Median glosso epiglottic fold
 Post surface : Tubercle

25. Aryepiglottic folds

26. • The tongue and the epiglottis are
connected by folds of mucous
membranes which form a small
space called the vallecula.

27. Vallecula

28. 2.LARYNGEAL JOINTS
 2 pairs of synovial joints
 Between the major cartilages of the
larynx:
 the cricothyroid and
 the cricoarytenoid.

29. Crico thyroid joint
 Synovial
 Rotatory
 around a transverse axis

30. Crico arytenoid joint
 Synovial
 Rotatory
 around a vertical
axis

31. Arytenocorniculate
Synovial or cartilaginous joints link the
arytenoid and corniculate cartilages

32. 3. MEMBRANES
 Extrinsic
Thyrohyoid membrane
Cricotracheal membrane
 Intrinsic
Quadrangular membrane
Conus elasticus

33. Thyrohyoid membrane
Provides an extensive
connection between the
thyroid cartilage and the
hyoid bone bilaterally
and anteriorly.

34. Cricotracheal membrane
connects the most
superior tracheal cartilage
with the inferior border of
the cricoid cartilage

35. QUADRANGULAR MEMBRANE
 The paired
Quadrangular
Membranes connect
the epiglottis with the
arytenoid and thyroid
cartilages

36. CONUS ELASTICUS
 Cricovocal membrane
 connects the cricoid
cartilage with the
thyroid and arytenoid
cartilages.

37.  Having 2 parts
Medial cricothyroid ligament
Lateral cricothyroid membranes

38. 4.LIGAMENTS &FOLDS OF LARYNX
 Epiglottic ligaments
 Aryepiglottic fold
 Vestibular ligament (vestibular folds or false
vocal cords)
 Vocal ligaments

39. Epiglottic ligaments
 Hyoepiglottic ligament
 Thyroepiglottic
ligament
 Median glossoepiglottic
ligament
 Lateral glossoepiglottic
or
pharyngoepiglottic fold

40. Aryepiglottic folds
 associated with the superior border of the
quadrangular membrane.
 constrict the entrance to the larynx and protect
the respiratory pathway

41. Vocal & vestibular folds

43. Boundaries
Ant : Epiglottis
Post :Ary epi glottic &
Inter arytenoid folds
Cavity of Larynx

44. Inter arytenoid notch

45. Divisions
Above VC : Supra glottic part
Below VC : Infra glottic part

46. ><Vestibular Rima Vestibuli / Introitus
><Vocal  Rima Glottidis
>< A-E folds  Aditus

47.  Sinus / Ventricle of the larynx
Cleft between vestibular & vocal folds
 Saccule : Upward prolongation of the anterior part of the sinus
Mucous glands ++

48. Vocal cord
 Ant 3/5 –
Inter membranous part
 Post 2/5 – Inter
cartilaginous part

49. 5.Mucous membrane
 Stratified squamous :
Epiglottis, Ary epi glottic folds , & Vocal folds
 Ciliated columnar :
Below vocal cords
 No mucous glands over the vocal cords

50. Histology of Cartilages
 Thyroid , cricoid & base of the Arytenoid :
Hyaline cartilage
 Epiglottis , Corniculate & Cuneiform , apex of
Arytenoid : Elastic cartilage

51. ELEVATORS OF THE PHARYNX
 The Suprahyoid Muscles
 Digastric
 Stylohyoid
 Mylohyoid
 Geniohyoid
 The Longitudinal Muscles of the
Pharynx
 Stylopharyngeus
 Salpingopharyngeus
 Palatopharyngeus
DEPRESSORS OF THE PHARYNX:
 The Infrahyoid Muscles
 Sternohyoid
 Sternothyroid
 Omohyoid
Extrinsic muscles
6.Muscles

52. Intrinsic
muscles

53. Intrinsic muscles

54. Crico thyroid
 Only intrinsic muscle of the larynx lying externally
 Supplied by Ext laryngeal N

55. Posterior crico arytenoid
 Lamina of cricoid posteriorly
 To muscular process of the arytenoid
 Only abductor of the vocal cords

56. Lateral crico arytenoid
 Arch of the cricoid
 Muscular pr of the arytenoid

57. Transverse arytenoid
 Only unpaired intrinsic muscle
 B/w Arytenoids

58. Oblique Arytenoid
 Cross each other obliquely
 Muscular process of one arytenoid to the apex of the
opposite arytenoid

59. Ary epiglotticus
 Fibers of the Oblique arytenoid
 Ary epiglottic fold
 Reach the edge of the epiglottic
cartilage

60. Thyro arytenoid
Angle of the thyroid cartilage &
Crico thyroid ligament
to
A/L surface of Arytenoid

61. Vocalis
Fibers of the Thyro arytenoid
to
Vocal ligament

62. Thyro epiglotticus
Fibers of the thyroarytenoid to aryepiglottic fold
which reach the edge of the epiglottis

63. ACTIONS

64. Muscles controlling the laryngeal inlet
 Oblique arytenoid
 Aryepiglottic muscle

65. Movements of the vocal cords
Adduction
Abduction
Folds closed (adducted) Folds open (abducted)
(View from above)
Glottis (space between folds)

66. Adductors of the vocal cords
Lateral cricoarytenoid
Transverse arytenoid

67. Abductor of the vocal cords
Posterior
cricoarytenoid

68. Muscle increasing the length &
tension of the vocal cords
 Cricothyroid: increases the
distance between the angle of
the thyroid cartilage & the
vocal processes of the
arytenoid cartilages, and
results in increase in the length
& tension of the vocal cords

69. Muscle decreasing the length &
tension of vocal cords
 Thyroarytenoid
(vocalis): pulls the
arytenoid cartilage
forward toward the
thyroid cartilage and
thus shortens and
relaxes the vocal
cords

70. Sphincteric function of the Larynx
There are two sphincters:
 At the inlet: used only
during swallowing
 At the rima glottis: used in
coughing and sneezing

71. Position of rest in quiet respiration
 Intermembranous part
of the rima glottidis
Triangular
 Intercartilaginous part
Rectangular

72. Forced inspiration
 Both parts of the
rima glottidis 
Triangular

73. Abduction of the vocal folds
The arrows indicate the lines of
pull of the Posterior Crico-
Arytenoid
Both parts of the rima glottidis
are triangular.

74. Closure of the rima glottidis
 The arrows indicate the
line of pull of the
Transverse arytenoid
 Both the vocal folds and
the arytenoid cartilages are
adducted
 No rotation of the
Arytenoid

81. BLOOD SUPPLY OF LARYNX :
ARTERIAL SUPPLY
 Upper Larynx
 External carotid artery
 Superior thyroid artery
 Superior laryngeal artery
 Lower Larynx
 Subclavian artery
 Thyrocervical artery
 Inferior thyroid artery
 Inferior laryngeal artery

82. Arteries to larynx
Superior laryngeal
Inferior Laryngeal

83. VENOUS DRAINAGE
 Upper Larynx
 Superior laryngeal
vein
 Superior thyroid vein
 Internal jugular vein
 Lower Larynx
 Inferior laryngeal
vein
 Inferior thyroid vein
 subclavian vein

84. Nerve supply
All intrinsic muscles except the
Cricothyroid by
Recurrent laryngeal nerve
Cricothyroid by
External laryngeal nerve

86. LYMPHATIC DRIANAGE
SUPRA GLOTTIC AREA
 upper deep cervical nodes-level of
the carotid bifurcation.
 prelaryngeal nodes.
INFRA GLOTTIC AREA
o pretracheal lymph nodes
paratracheal nodes
o deep cervical and superior
mediastinal nodes.

87. APPLIED ANATOMY
Unilateral palsy B/L palsy

88. Singer’s or teacher’s nodules

89. Laryngeal edema

90. laryngitis

91. laryngotomy

92. Thank you…