Anatomy of larynx

1. Anatomy and
physiology of
Larynx

2. OUTLINE
• CARTILAGES
• LIGAMENTS
• MUSCLES
• INNERVATION
• BLOOD SUPPLY
• LYMPHATICS

3. Larynx
• The larynx is the portion of the respiratory tract
containing the vocal cords
• Situated at the upper end of trachea Opposite 3rd – 6th
cervical vertebrae

5. The Larynx: Important Relations
• The larynx related to major
critical structures:
 Carotid arteries ,
jugular veins, and
vagus nerve
 Superior and inferior
thyroid arteries
 Superior and
recurrent laryngeal
nerves

6. Structure
• The larynx consists of four
basic components:
 A cartilaginous
skeleton
 Membranes and
ligaments
 Intrinsic and
extrinsic muscles
 Mucosal lining

7. Laryngeal Cartilages
• The cartilaginous skeleton
is comprised of :
 Single Cartilages:
 Thyroid
 Cricoid
 Epiglottis
 Paired Cartilages:
 Arytenoid
 Corniculate
 Cuneiform

9. • All the cartilages, except the
epiglottis, are of hyaline type.
• Epiglottis is formed of elastic
cartilage
• The cartilages are:
 Connected by
joints, membranes
& ligaments
 Moved by muscles

10. Laryngeal Cartilages
THYROID CARTILAGE:
Shield like , longest Meet at midline – Thyroid notch (
angle 90 /120 degrees) so-called Adam's apple.

11. • Has two laminae, which meet in
the midline and form a
prominent angle, called
laryngeal prominence (Adam’s
apple).
• Outer surface of each lamina
shows an oblique line which
gives attachment to thyrohyoid,
sternothyroid & inferior
constrictor of the pharynx
• The superior border gives
attachment to the thyrohyoid
membrane
Obliqu
e line
superio
r cornu
inferior
cornu

12. Superior cornu: long, narrow, curves upwards, backwards and
medially,

13. • Inferior cornu: shorter, thicker, curves downwards &
medially.

14. Cricoid Cartilage
• Lies below the thyroid
cartilage
• Forms a complete ring
• Has a narrow anterior arch
& a broad posterior lamina
• Has an articular facet on its:
• Lateral surface for articulation with
inferior cornu of the thyroid
cartilage.
• Upper border for articulation with
base of arytenoid cartilage.

15. EPIGLOTTIS
• - leaf shaped
• cartilage
• posterior to root
• of tongue
• - connected to
• body of hyoid
• and post side of
• thyroid cartilage
POST.
VIEW

16. Arytenoid Cartilages
• Small, pyramidal in shape
• Situated at the back of the
larynx
Has:
• A base articulating with the
upper border of the cricoid
cartilage
• An apex supporting the
corniculate cartilage
• A vocal process projecting
forward, gives attachment to
the vocal ligament
• A muscular process projecting
laterally, gives attachment to
muscles

18. Corniculate & Cuneiform Cartilages
Corniculate Cartilages
• Small nodules
• Articulate with the a pices of
arytenoid cartilages
E
CU
CO
V
F

20. Corniculate & Cuneiform Cartilages
Cuneiform Cartilages
• Small rod shaped, placed in each aryepiglottic fold,
producing a small elevation
• Do not articulate with any other cartilage
Serve as support for the ary-epiglottic fold
E
CU
CO
V
F

21. • Ligaments A
sheet or band of tough,
fibrous tissue connecting
bones or cartilages at a
joint or supporting an
organ.
• Membrane A
thin, pliable sheet or layer
of animal or vegetable
tissue, serving to line an
organ, connect parts.

22. • Muscle is a soft tissue found in most animals. Muscle cell
s contain protein filaments of actin and myosin that slide
past one another, producing a contraction that changes
both the length and the shape of the cell. Muscles
function to produce force and motion
The portion of the cavity of the larynx above the vocal folds is called the
vestibule; it is wide and triangular in shape, its base or anterior wall
presenting, however, about its center the backward projection of the
tubercle of the epiglottis. It contains the ventricular folds, and between
these and the vocal folds are the ventricles of the larynx.

23. Membranes & Ligaments
• Thyrohoid membrane, median &
lateral thyrohoid ligaments
• Median cricothyroid ligament
• Cricotracheal membrane
• Hyoepiglottic ligament
• Thyroepiglottic ligament

24. • Quadrangular membrane:
• Extends between the epiglottis
and the arytenoid cartilages
• Its lower free margin forms the
vestibular ligament that lies
within the vestibular fold
• Cricothyroid membrane
(conus elasticus):
• Lower margin is attached to
upper border of cricoid
cartilage
• Upper free margin forms vocal
ligament that is attached
anteriorly to deep surface of
thyroid cartilage & posteriorly
to the vocal process of
arytenoid cartilage

25. Cavity of the larynx
• Cavity of the larynx Divided by vestibular & vocal folds
into 3 compartments.
• Superior vestibule Ventricle
• sinus of the larynx
• Rima glottidis / glottis Rima vestibuli

27. Vestibule
• Vestibule is an opening in the lateral wall of larynx,
between the vestibular fold superiorly and vocal folds
inferiorly. It is the inlet to another cavity in the lateral wall
of larynx, namely ventricle. The vestibular fold is formed
by the vestibular ligament extending from lateral walls of
epiglottis to arytenoid cartilage covered with mucous
membrane. Vocal fold is the upper free margin of conus
elasticus which is covered by mucous membrane. The
conus elasticus forms inferiorly the lateral cricothyroid
ligament.

28. • Vestibule
The portion of the cavity of the larynx above the vocal
folds is called thevestibule; it is wide and triangular in
shape, its base or anterior wall presenting, however,
about its center the backward projection of the tubercle
of the epiglottis. It contains the ventricular folds, and
between these and the vocal folds are the ventricles of
the larynx.

29. LARYNGEAL
VENTRICLE
• LARYNGEAL VENTRICLE: Laryngeal sinus Elongated
recess between vestibular & vocal folds.

30. Vestibular folds
• Thick, pink folds of mucous membrane Encloses the
vestibular ligament.
• Anterior attachment is to angle of thyroid cartilage,
inferior to epiglottis
• Posterior attachment to anterolateral surface of arytenoid
cartilage superior to vocal process

31. Vocal fold
• Vocal fold Extends from the middle of angle of the
thyroid cartilage to vocal process of arytenoid cartilage
vibrates maximum during phonation

32. GLOTTIS
• Opening between the vocal folds.

33. Blood supply
• Laryngeal branch of superior thyroid artery (br. of
external carotid).
• Laryngeal branch of inferior thyroid artery (br. of
thyrocervical trunk of 1st part of subclavian)

34. Nerve supply
• muscles of the larynx receive their innervation via the
RECURRENT LARYNGEAL BRANCH of the vagus.
• Exception: The CRICOTHYROID MUSCLE, which
receives its innervation via the EXTERNAL LARYNGEAL
NERVE.

35. Sensory Innervations
• Above the vocal folds the sensory innervations of the
larynx is via the INTERNAL LARYNGEAL NERVE.
• Below the vocal folds it is by way of branches of the
RECURRENT LARYNGEAL NERVE.
• PARASYMPATHETIC INNERVATION OF THE LARYNX
is mainly by way of branches of the vagus nerve.

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