ANATOMY

1. Anatomy Of Larynx

2. Principal Internal Features of the
Larynx
The cavity of the larynx
extends
above – from the area of
the tip of the
epiglottis,aryepiglottic
folds, and
interarytenoid folds
below — to the 1st
tracheal ring

3. Internal cavity of the larynx
divided into 3 spaces:
• Supraglottic,
• Glottic, And
• Subglottic spaces

4. Intrinsic Membranes
• connect the laryngeal
cartilages with each
other to regulate
movement.
• There are 2 intrinsic
membranes :
1. Conus Elasticus and
2. Quadrangular
membranes.

5. CONUS ELASTICUS
• Conus Elasticus connects
the cricoid cartilage with
the thyroid and arytenoid
cartilages.
• composed of dense
fibroconnective tissue
with abundant elastic
fibers.

6. CONUS ELASTICUS
• Having 2 parts
1 .Medial cricothyroid ligament
connects the anterior part of the
arch of the cricoid cartilage with
the inferior border of the thyroid
cartilage.
2. Lateral cricothyroid
membranes originate on the
superior surface of the cricoid
arch and rise superiorly and
medially to insert on the vocal
process of the arytenoid
cartilages posteriorly, and to the
interior median part of the
thyroid cartilage anteriorly.
• Its free borders form the
VOCAL LIGAMENTS

7. Quadrangular Membrane
• Extends from the sides of
the epiglottic cartilage
anteriorly to the
anterolateral surface of the
arytenoid cartilage and
posteroinferiorly to the
corniculate cartilage.
• With its covering of mucous
membrane forms the
aryepiglottic fold superiorly
and vestibular ligament
inferiorly.
• it forms the medial wall of
the piriform recess

8. • The paired Quadrangular
Membranes connect the
epiglottis with the arytenoid
and thyroid cartilages.
• Course posteriorly downward
and attach to the corniculate
cartilages and the lateral
surfaces of the arytenoids.
• The cuneiform cartilages are
embedded within the
aryepiglottic folds.
• The free inferior borders of the
quadrangular membranes form
the ventricular ligaments, also
known as the false vocal folds.

9. Intrinsic laryngeal muscles
1. Abductors of the vocal cords.
2. Adductors of the vocal cords.
3. Tensors of the vocal cords.
4. Openers of laryngeal inlets.

10. Intrinsic Muscles
• The intrinsic muscles are:
 Cricothyroid
 Posterior cricoarytenoid
 Lateral cricoarytenoid
 Arytenoid with its
transverse and oblique
fibers
 Thyroarytenoid and its
thyroepiglottic and
components

11. Abductors of the vocal cords
Posterior crico-arytenoid
muscle.
originate from posterior surface of the
lamina of cricoid cartilage.
run superolaterally to converge on the
muscular processes of the arytenoid
cartilage.
abduction and externally rotate the
arytenoid cartilage to open the rima
glottidis.
are innervated by recurent laryngeal
branches of the vagus nerve (CN X).

13. Posterior crico-arytenoid muscle

14. Adductors of the vocal cords
• Are 3 on each side:
1. Lateral crico-arytenoid muscle.
2. Transverse portion of interarytenoid muscle.
3. External portion of thyro-arytenoid muscle.

15. Lateral crico-arytenoid muscle

16. Lateral crico-arytenoid muscle
• originates from the upper
surface of the arch of the
cricoid cartilage.
• runs posterosuperiorly to
insert on the muscular
process of the arytenoid
cartilage.
• adduct and internally rotate
the arytenoid cartilage-
adducted vocal folds with
an open air channel
posteriorly between
adjacent arytenoid
cartilages.
• are innervated by the
recurrent laryngeal
branches of the vagus nerve
(CN X).

17. Transverse portion of interarytenoid muscle
• is a single muscle.
• spans the distance
between adjacent lateral
margins of the arytenoid
cartilages and covers the
posterior surfaces of
these cartilages.
• is innervated by the
recurrent laryngeal
branches of the vagus
nerve (CN X).

19. External portion of thyro-arytenoid muscle
• are broad flat muscles lateral
to the fibro-elastic membrane
of the larynx and the laryngeal
ventricles and saccules.
• run from a vertical line of
origin on the lower half of the
thyroid angle and adjacent
external surface of the
cricothyroid cartilage.
• Some of the fibers may
continue into the aryepiglottic
fold and reach part of thyro-
epiglottic muscle.

21. Thyro-arytenoid muscle

22. Tensors of the vocal cords
1. Cricothyroid muscle ( external tensor).
2. Internal portion of thyro-arytenoid (vocalis
muscle).

23. Cricothyroid muscle
(external tensor)
• are fan-shaped muscles.
• are attached to the arch of the
cricoid cartilage and attach to
the thyroid cartilage.
• have two parts; oblique and
straight.
• Oblique part runs in a
posterior direction from the
arch of the cricoid cartilage to
the inferior horn of the thyroid
cartilage.
• Straight part runs more
vertically from the arch of the
cricoid cartilage to the
posteroinferior margin of the
thyroid lamina.

24. Action of cricothyroid muscle
• move the cricothyriod joints.
• pull the thyroid cartilage
forward and rotate it down
relative to the cricoid cartilage-
lengthen the vocal folds.
• 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
• are the only one intrinsic (lies
outside) muscles innervated by
the superior laryngeal branches
of the vagus nerve (CN X).

25. Internal portion of thyro-arytenoid (vocalis muscle)
• are elongate muscles lateral to and
running parallel with each vocal
ligament.
• attaches posteriorly to the lateral
surface of the vocal process and
adjacent depression on the
anterolateral surface of the arytenoid
cartilage.
• insert anteriorly along the length of
the vacal ligament to the thyroid
angle.
• pulls the arytenoid cartilage forward
toward the thyroid cartilage and thus
shortens and relaxes the vocal cords
• adjust tension in the vocal folds.
• are innervated by the recurrent
laryngeal branches of the vagus
nerve (CN X).

27. Openers of the laryngeal inlet
Thyro-epiglottic muscle
are broad flat muscles
lateral to the fibro-
elastic membrane of
the larynx and the
laryngeal ventricles
and saccules.
run from a vertical line of
origin on the lower half
of the thyroid angle
and adjacent external
surface of the
cricothyroid cartilage.
Some of the fibers may
continue into the
aryepiglottic fold and
reach part of thyro-
epiglottic muscle.

28. Closers of the laryngeal inlet.
Oblique portion of interarytenoid muscle
• are pair muscles.
• run from the posterior surface of the
muscular process of one arytenoid
cartilage to the apex of the arytenoid
cartilage on the other side.
• Some fibers of this muscle continue
laterally around the margin of the
arytenoid cartilage and into the
aryepiglottic fold to continue as part
of aryepiglottic muscle.
• can narrow the laryngeal inlet by
constricting the distance between the
arytenoid cartilage and the epiglottis.
• is innervated by the recurrent
laryngeal branches of the vagus
nerve (CN X)

30. Closers of the laryngeal inlet
Aryepiglottic muscle

31. Cavity of the larynx
 2 folds
1. False vocal cord.
2. True vocal cord.
 3 parts
1. Vestibule.
2. Ventricle.
3. Subglottic space
• Extends from the inlet of the larynx to the lower
border of the cricoid cartilage, it is divided into 3
parts by 2 folds of mucous membrane:

32. Ligaments & Folds OF Larynx
• Epiglottic ligaments
• Aryepiglottic fold
• Vestibular ligament (vestibular folds or false vocal
cords)
• Vocal ligaments

33. 1 . Epiglottic Ligaments and Folds
• Hyoepiglottic ligament
• Thyroepiglottic ligament
• Median glossoepiglottic
ligament
• Lateral glossoepiglottic or
pharyngoepiglottic fold,
• attached between the base
of the epiglottic cartilage
and the pharyngeal wall at
the root of the tongue

34. 2 . Aryepiglottic Folds
• one on each side,
• contain the aryepiglottic
muscles.
• associated with the
superior border of the
quadrangular membrane.
• Both aryepiglottic folds
constrict the entrance to
the larynx and protect the
respiratory pathway by not
permitting food, liquids,
and foreign bodies to
enter the larynx and
trachea.

35. 3 . Vestibular Folds
(False Vocal Cords)
• formed by the inferior edge of the
quadrangular membrane.
• Attached in front to the thyroid
cartilage just below the attachment
of the epiglottic cartilage
• Connected behind to the
anterolateral surfaces of the
arytenoid cartilages.
• The vestibular ligaments are located
just above the vocal ligaments,
separated from them by bilateral
ellipsoid spaces called the laryngeal
ventricles.
• Overlap the true vocal folds just
prior to a cough or sneeze —
reinforcing the resistance offered
by the true vocal folds against the
internal expiratory pressures.

36. 4.Vocal Ligaments, Vocal
Cords, and Vocal Folds
• The thickened,
ligamentous, upper edges
of the elastic tissue of the
conus are the vocal
ligaments or vocal cords.
• Extend from the medial
extremities of the laminae
of the thyroid cartilage in
the midline anteriorly
(forming the anterior
commissure) to the apices
of the vocal processes of
the arytenoid cartilages on
each side posteriorly.

37. Structure of Vocalcord
• Histologically 5 layers:
• LAYER 1: is the squamous epithelial lining. It is very thin and helps to hold the
shape of the vocal fold. This layer doesnot contain any mucous glands.
• LAYER 2: superfical layer of the lamina propria. It is composed of loose fibers and
matrix .
• This layer contains only minimal elastic and collagenous fibers and offers least
resistance to vibration. The integrity of this layer is vital for proper phonatory
function.
• LAYER 3: intermediate layer of lamina propria.
• It contains a higher concentration of elastic and collagenous fibers when
compared to layer 2. This layer is thickened at the anterior and posterior ends of
the vocal folds. These thickened regions are known as anterior and posterior
macula flava. These structures provide protection to the vocal folds from
mechanical damage.
• LAYER 4 : deep layer of lamina propria.
• It contains a dense collection of elastic and collagenous fibers. This layer along
with the intermediate layer constitute the vocal ligament. Some of the
collagenous fibers present here gets inserted into the vocalis muscle. LAYER 5:
formed by the vocalis muscle. The fibers of this muscle run parallel to the
direction of the vocal fold.

39. • Vocalis muscle is infact a portion of thyro
arytenoid muscle.
• At the anterior most portion of the vocal fold a
mass of collagenous tissue is present--known
as the anterior commissure tendon
or Broyle's ligament.
• This ligament gets attached to the inner area
of thyroid cartilage which is devoid of
perichondrium.
• Lacking a submucosa and blood vessels, the
vocal ligaments appear to be pearly white and
shiny.
• The space between the true vocal cords (the
intermembranous space) is known as the rima
glottidis

40. Surgical Considerations
• The epithelium of the true vocal cords does not have lymphatics.
Therefore, metastatic disease is a rare phenomenon.
• The vocal folds are devoid of lymphatics, and it infact clearly forms
the watershed zone between the upper and the lower group of
lymphatics.
• The pathway of metastasis of glottic cancer is via the Delphian
node or paratracheal nodes and finally nodes of the superior
mediastinum.

41. Laryngeal Mucosa
• Is mostly of the respiratory type called ciliated columnar
epithelium,
• certain areas of the larynx covered with stratified squamous
epithelium are-
 upper area of the anterior , dorsal epiglottic surfaces,
 the ventral half of the aryepiglottic folds, and
 the vocal cords.
• Mucous membrane of the supraglottic larynx is a
downward continuation of the oropharyngeal mucosa.
• Infraglottic region of the larynx is made of normal
respiratory mucosa
• Mucous glands are found at the posterior surface of the
epiglottis, aryepiglottic fold, and laryngeal appendices.

42. Laryngeal Spaces
• Internal laryngeal
spaces :
 vestibule,
 ventricles,
 subglottic or
infraglottic spaces
o External laryngeal
spaces
 Paraglottic space
 pre-epiglottic. Space

43. Internal Spaces (Laryngeal Cavity)
VESTIBULE
• pyramid -shaped space
extends from the laryngeal
inlet or aditus to the
vestibular folds (false vocal
cords).
• Bounded ventrally by the
posteroinferior surface of
the epiglottis, dorsally by
the corniculate cartilages
and apices of the
arytenoids, and laterally by
the aryepiglottic folds and
the piriform recesses.

44. Laryngeal Ventricles
• Compsed of 2 parts
1. Saccule.
2. Rimaglottidis.
• sinuses (of Morgagni), are
diverticula of the interval
between the false and true
vocal cords.
• It is lined internally by
mucosa and covered
externally by a very thin
layer of elastic tissue and the
thin thyroarytenoid muscle.
• The anterior end of the
ventricle may possess an
additional external
expansion, the laryngeal
saccule,

45. Saccule
• The saccule is a conical
pouch which ascends
from the anterior part of
the ventricle
• It lies between the inner
surface of thyroid
cartilage and the false
cords.
• Numerous mucous glands
open onto the surface of
its lining mucosa.

46. Rima glottidis
Subdivided into 2 parts,
• Posterior 2/5 –
intercartilaginous part
(respiratory glottis,or
interarytenoid space), between
the arytenoid cartilages and
• Anterior 3/5 — the
intermembranous part or glottis
vocalis.
• Its average length:
In the adult male is about 2.5 cm.
In the adult female is about 1.6 cm.

47. Surgical Considerations.
• Enlargement of the laryngeal
saccule is often referred to as
a laryngocele.
• Any obstruction of the
laryngeal ventricle, such as a
ventricular carcinoma, may
lead to the formation of a
laryngocele.
• A laryngocele may bulge
through the aryepiglottic fold
and obstruct the endolarynx
( internal laryngocele ).
• It may be present outside of
the thyrohyoid membrane (
external laryngocele ).
• The enlargement may even be
a combined
internal and external
laryngocele

48. Subglottic (Infraglottic)
Space
• the distal part of the
laryngeal cavity.
• extends from the glottis to
the inferior border of the
cricoid cartilage.
• The subglottic space begins
below the curve formed by
the vocal fold to the lower
end of cricoid cartilage
• SURGICAL IMPORTANCE :
• Narrowest area in infants ,
so edema obstruction &
respiratory distress occur
early

49. External Spaces
• Supraglottic laryngeal area is subdivided
into 3 laryngeal spaces
• Paired Lateral Paraglottic Spaces
• One midline Pre-Epiglottic Space

50. Paraglottic Spaces
(Tucker’s space)
• Bounded laterally by
the thyroid cartilage,
• inferomedially by the
conus elasticus,
• medially by the
ventricle and the
quadrangular
membrane

51. Pre-Epiglottic Space ( Boayer’s space )
• Bounded superiorly by the
hyoepiglottic ligament,
anteriorly by the thyrohyoid
membrane and ligament, and
Posteroinferiorly by the
epiglottis and thyroepiglottic
ligament.
• The pre-epiglottic space
forms an inverted pyramid.
• continuous with the superior
portion of the
paraglottic space.
• contains abundant fat, blood
vessels, lymphatics,and
mucosal glands.

52. Surgical Considerations
• Epiglottic (supraglottic) carcinoma may
spread through perforations in the
epiglottis into the pre-epiglottic space.
• Since the pre-epiglottic space
communicates laterally with the
paraglottic spaces, a carcinoma is free to
spread beyond the internal boundaries of
the larynx.
• Therefore, supraglottic laryngectomy
may be contraindicated

53. Function of the Larynx
• is an elaborate sphincter for the lower
respiratory tract.
• provides a mechanism for producing sounds.
• adjusts the size of the ventricle cavity result
from changes in the dimensions of the rima
glottidis, rima vestibuli, vestibule, and the
laryngeal inlet.
• This changes result from the muscle actions
and laryngeal mechanics.

54. During Quiet Respiration
• The laryngeal inlet,
vestibule, rima
vestibule and rima
glottidis are open.
• The arytenoid
cartilages are
abducted.
• The rima glottidis in
triangular shaped

55. During Force Respiration
• The arytenoid cartilage
are rotated laterally,
mainly by action of the
posterior crico-
arytenoid m.
• As a result, the vocal
folds are abducted,
and the rima glottidis
widens into a
rhomboid shape,
which effectively
increases the diameter
of the laryngeal airway.

56. Phonation
• Arytenoid cartilages and
vocal folds are adducted and
air is forced through the
closed rima glottidis.
• This action causes the vocal
folds to vibrate against each
other and produce sounds,
which can then be modified
by the upper parts of the
airway and oral cavity.
• Tension in the vocal folds
can be adjusted by the
vocalis and cricothyroid
muscle.

57. Effort Closure
• occurs when air is retaind in
the thoracic cavity to stablize
the trunk, for example during
heavy lifting, or as part of the
mechanism for increasing
intra-abdominal pressure.
• During effort closure, the rima
glottidis is completely closed,
as is the rima vestibuli and
lower parts of the vestibule.
• The result is to completely and
forcefully shut the airway.

58. During Swallowing
• The rima glottidis, the rema
vestibuli, and vestibule are
closed and the laryngeal inlet
is narowed.
• The larynx is move upward and
forward causes the epiglottis
to swing downward towards
the aryngeal inlet (also
facilitate closing the laryngeal
inlet and opening the
esophagus).
• All these actions together
prevent solids and liquids from
entry into the airway and
facilitate their movement
through the piriform fossae
into the esopahgus.

59. Blood supply of the larynx
1. Laryngeal branches of the superior thyroid
artery.
2. Laryngeal branches of the inferior thyroid
artery.
3. Cricothryoid branches of superior thyroid
artery (cross the midline at the upper part of
the cricothyroid membrane).

60. Blood supply of
the larynx
Inferior thyroid artery
superior thyroid artery

61. Nerve supply of the larynx
supplied by branches of vagus
• Superior laryngeal nerve,
has 2 branches:
1. Internal.
2. External.
• Recurrent (Inferior)
laryngeal nerve :
1. Anterolateral (motor)
2. Posteromedial(sensory)

62. Superior laryngeal nerve
External branch
• Travel down on
the inferior
constrictor
muscle of the
pharynx.
• Supplies the
cricothyroid
muscle and part
of the anterior
subglottis.

63. Suprior laryngeal nerve
Internal branch
-Entirely sensoy.
- Pierces the
thyrohyoid
membrane with the
superior laryngeal
artery and vein.
-Supplies the cavity of
the larynx as far
down as the level
of the vocal cords.

64. Recurrent (Inferior) laryngeal nerve
• longer coarse on the
left.
• In the left it turns
round the arch of the
aorta.
• On the right it turns
round the subclavian
artery.
• In the neck it lies
between the trachea
and the oesophagus

65. Recurrent (Inferior) laryngeal nerve
• Its terminal part passes upward, under cover of the ala
of the thyroid cartilage immediately behind the
inferior cricothyroid joint, it then divided into:
1. Anterolateral (motor) branch which supplies all the
intrisic muscles of the larynx except cricothyroid
muscle.
2. Postromedial (sensory) branch which supplies the
cavity of the larynx below the level of the vocal cords.

66. Lymphatic drainage of the larynx
• Vocal cord has no lymphatic vessels.
• The edges of the vocal cord divide the lymphatic
of the larynx into 2 parts:
1. Supraglottic drain into:
2. Subglottic drain into:
 Pre-epiglottic nodes.
 Upper deep cervical nodes.
•Prelaryngeal and pretracheal nodes.
•Lower deep cervical.

67. Lymphatic drainage of the larynx

68. Symptoms of laryngeal disease
• Generally the laryngeal diseases are characterized by:
1. Hoarseness of the voice which means rough voice, maybe a
manifestation of any laryngeal disease whether congenital, traumatic,
inflammatory, or neoplastic, or as a systemic disease as hypothyroidism ,
lung cancer.
2. Stridor: this is produced by the turbulence of diminished air flow at the
nearly completely or partially obstructed larynx in the form of musical
sounds, it’s usually inspiratory at the supraglottic and glottic and by
phasic in the subglottic down to the carrina, expiratory stridor (wheez) at
the lower air passages.
3. Aspiration: inhalation of the food or saliva due to failure of the
protective sphencteric function of the larynx manifested as chocking or
coughing during swallowing or chest infection due to saliva soiling in the
lungs.
4. Pain: it maybe felt in the larynx or referred to the ear (otalgia) through IX
& X CN.

69. Signs of laryngeal disease
1) Voice abnormality (dysphonia): abnormal voice
ranging from aphonia to hoarseness of voice.
2) Stridor.
3) Mobility: laryngeal mobility due to swallowing
and phonation (which is normally palpable) may
be impalpable in laryngeal disease.
4) Neck lump: this is maybe due to lartngeal
disease itself or metastasis to the neck
lymphnodes.