5. • is a hollow muscular ligament structure with cartilagenous
framework.
• Its cavity continuous below with the trachea, and above
opens into the pharynx.
• is a valve (or sphincter) to close the lower respiratory tract
(protection)
• and an instrument to produce sound.(phonation)
• Respiration
• Deglutition
6.
7. • Extent
• Root of tongue – trachea
• Front of 3,4,5,6 cervical vertebrae
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20. Larynx
• Three
large unpaired cartilages
(cricoid, thyroid, and epiglottis)
• Three pairs of smaller cartilages
(arythenoid, corniculate, and cuneiform)
• A fibroelastic membrane and
numerous intrinsic muscles
21. Epiglottis
• is a leaf-shaped cartilage.
• is attached by its stem to the
posterior aspect of the thyroid
cartilage by thyro-epiglottic
ligament.
• projects posterosuperiorly.
• Its upper margin is behind the
pharyngeal part of the tongue.
• Its inferior half of the posterior
surface of the epiglottis is
raised slightly to form an
epiglottic tubercle.
22.
23. Thyroid cartilage
• is the largest of the
laryngeal cartilages.
• is formed by joining of a
right and a left lamina
anteriorly as the
laryngeal prominence
(A’dam’s apple ).
• are widely separated
posteriorly.
24. Thyroid cartilage
• The angle between
the two laminae is
more acute in men
(90 C) than in
women (120 C) so
the laryngeal
prominence is more
apparent in men
than women.
25.
26.
27.
28. Cricoid cartilage
• is inferior of the
laryngeal cartilage and
completely encircles the
airway.
• is shaped like a ‘signet
ring’ with a broad lamina
of cricoid cartilage.
• C6
• Foundation stone
31. Surface of Arytenoid cartilarges
• Base is concave and articulates with the
sloping articular facet on the lamina of
cricoid cartilarge.
• Apex articulates with a corniculate
cartilage.
• Medial surface of each cartilage faces the
other.
• Anterolateral surface has two depressions
for muscle (vocalis) and ligament
(vestibular ligament) attachment.
32. Base of Arytenoid Cartilarges
• Elongated Anterior angle is vocalis process
for the vocal ligament attachment.
• Lateral angle is muscular process for
attachment of the posterior and lateral
crico-arythenoid muscles.
33. • Corniculate cartilages
articulate with the apices
of the arytenoid cartilage.
• Corniculate apices project
posteromedially towards
each other.
• Cuneiforms are suspend in
the part of the
fibroelastic membranearyepiglottic membrane.
34. • Thyroid, cricoid and basal parts of
arytenoid are composed of hyaline
cartilage – ossify after 25
• Apex of arytenoid and all other are
elastic cartilage
35.
36. Laryngeal Joint; Crico-thyroid Joint
•
•
1.
2.
•
Synovial joint
Compose of
Crico-thyroid joint
Crico-arytenoid joint
The cricothyroid joints
enable the thyroid cartilage
to move forward and tilt
downwards on the cricoid
cartilage (effectively
lengthens and puts tension on
the vocal ligaments).
37. Laryngeal Joint; Crico-aretynoid Joint
• between the cricoid
cartilage and of the
arytenoid cartilages.
• enable the arythenoid
cartilages to slide away or
towards each other and to
rotate so that
• The vocal process pivot
either towards or away from
the midline (abduct and
adduct the vocal ligament).
39. Cricothyroid ligament
• is attached to the arch of
cricoid cartilage and extends
superiorly.
• Thyroid cartilage anteriorly
and vocal process posteriorly.
• The free margin of this
ligament is thickened to form
the vocal ligament, which is
under the vocal fold (true
‘vocal cord’) of the larynx.
• is also thickened anteriorly in
the midline to form a distinct
median cricothyroid ligament.
40. Quadrangular Membrane
• Run between the lateral
margin of the
anterolateral surface of
the arytenoid cartilage on
the same side to epiglottis
superiorly
• Its free lower margin is
thickened to form the
vestibular ligament under
the vestibular fold (false
‘vocal cord’).
41. Vestibular Ligament
• Vestibular ligament
is attached
posteriorly to the
arytenoid cartilage
and anteriorly to
the thyroid angle
just superior to
the attachment of
the vocal ligament.
42.
43. Cavity of the larynx
• is tubular in shape.
• is lined by the mucosa.
• opens superiorly (laryngeal inlet) into the anterior
aspect of the pharynx just below and posterior to
the tongue.
• opens inferiorly into the lumen of trachea.
• Laryngeal inlet can be closed by downward movement
of epiglottis whereas the inferior opening is
continuously open.
• Wall of laryngeal cavity:
Lateral wall: aryepiglottic folds.
Anterior border: mucosa covering the superior
margin of the epiglottis.
Posterior border: interarytenoid notch (between the
two corniculate tubercles).
44.
45. Three Division of Laryngeal Cavity
•
Two pairs of mucosal fold (vestibular and vocal
folds) divide the cavity into three major regions;
1. Vestibule is (upper chamber) between the
laryngeal inlet and the vestibular ligament.
2. (Laryngeal) Ventricle (middle chamber) is
between the vestibular folds above and the vocal
folds below.
3. Infraglottic space (inferior chamber) is between
the vocal folds and the inferior opening of the
larynx.
46.
47. Laryngeal Ventricles and Saccules
• produce an expanded
trough-shaped space.
• Larygeal saccule is an
elongate tubular
extension of each
ventricle projects
anterosuperior between
the vestibular fold and
thyroid cartilage.
• Within the walls of the
saccule are numerous
mucous glands which
secrete the mucus to
lubricate the vocal folds.
48. Rima Vestibuli
• is a triangular-shaped
opening.
• is between the two
adjacent vestibular folds
at the entrance to the
middle chamber of the
laryngeal cavity.
• Its apex is anterior.
• Its base is formed by
the posterior wall of the
laryngeal cavity.
49. Rima Glottidis
• is between the two
adjacent vocal folds.
• separates the middle
chamber above from
the infraglottic cavity
below.
• It base is formed by
the fold of mucosa
(inter-arytenoid fold)
at the bottom of the
inter-arytenoid notch.
Both the rima glottidis and the
rima vestibuli can be opened and
closed by movement of the
arytenoid cartilages and associated
fibro-elastic membrane.
50. Function of Intrinsic Muscles
• adjust tension in the vocal ligaments.
• open and close the rima glottidis.
• control the inner dimensions of the
vestribule.
• close the rima vestibuli.
• facilitate closing of the laryngeal inlet.
51. Action of Intrinsic Muscles
• Acting on the cricothyroid and cricoarytenoid joints.
• Adjusting the distance between the
epiglottis and arytenoid cartilage.
• Pulling directly on the vocal ligament.
• Forcing soft tissues associated with the
quadrangular membranes and vestibular
ligaments toward the midline.
52.
53. Cricothyroid Muscles
• 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.
54. Cricothyroid Muscles
• move the cricothyriod joints.
• pull the thyroid cartilage forward and rotate it down
relative to the cricoid cartilage-lengthen the vocal
folds.
• are the only one intrinsic (lies outside) muscles
innervated by the superior laryngeal branches of the
vagus nerve (CN X).
• All other intrinsic muscles are innervated by the
recurrent laryngeal branches of the vagus nerves.
55.
56. Posterior crico-arytenoid muscle
• originate from shallow
depression on the 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).
57.
58. Lateral Crico-arytenoid Muscles
• 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).
59.
60.
61. Transverse arytenoid m.
• 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).
62.
63. Oblique arytenoid muscles
•
•
•
•
•
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)
64. Vocalis
• 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.
• adjust tension in the vocal folds.
• are innervated by the recurrent
laryngeal branches of the vagus
nerve (CN X).
65. Thyro-arytenoid Muscles
• 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.
66.
67.
68. 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.
69. 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.
70. 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.
71. 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.
72. 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 intraabdominal 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.
73. 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.
74.
75. Tracheostomy
• is a procedure in which a hole is made in the
trachea and a tube is inserted to enable
ventilation when the foreign body obstruct to the
larynx.
• A small transverse incision is placed in the lower
third of the neck anteriorly (at level 2nd and 3rd
tracheal rings), deviates the strap muscle laterally
and divides the isthmus of the thyroid gland.
• Pateint with long-term tracheostomies are unable
to vocalize because no air is passing through the
vocal cords.
76. Arterial Supply
• Superior laryngeal a.
originates from the
superior thyroid a. and
accompaneis the internal
branch of the superior
laryngeal nerve through
the thyrohyoid membrane.
• Inferior laryngeal a.
originates from the
inferior thyroid branch of
thyrocerical trunk,
together with the
recurrent laryngeal n.
77. Veins draining the larynx
• Superior laryngeal veins
drain into superior
thyroid veins, which in
turn drain into the
internal jugular vein.
• Inferior laryngeal veins
drain into inferior
thyroid veins, which drain
into the left
brachiocephalic veins.
78. Lymphatics
• drain regions above and below the vocal folds:
• Those above the vocal fold follow the superior
laryngeal a. and terminate in deep cervical nodes
associated with the bifurcation of the common
carotid a.
• Those below the vocal folds drain into deep nodes
associated with the inferior thyroid a. or with
nodes associated with the front of the
cricothyroid ligament or upper trachea.
79. Nerves
Sensory and
motor is supplied
by 2 branches of
vagus nerve:
1. Superior laryngeal
nerve
2. Recurrent
laryngeal nerve
•
80. Superior Laryngeal Nerve
Originate from the inferior vagal
ganglia.
Divide into internal and external
•
branches just above the level of
the superior horn of the hyoid
bone.
1.
External branch (external
laryngeal br.) decends along the
lateral wall of the pharynx to
supply and penetrate the inferior
constrictor of the pharynx and
ends by the supplying the
cricothyroid muscle.
2. Internal branch (internal laryngeal
nerve) passes anteroinferiorly to
penetrate the thyrohyoid
membrane.
(it is mainly sensory and supplies the
laryngeal cavity above
level of the vocal folds.)
•
81. Recurrent Laryngeal Nerves
• Sensory to the laryngeal
cavity below the level of the
vocal folds.
• Motor to all intrinsic muscles
of the larynx except for the
cricothyroid.
• Left recurrent laryngeal n.
originates in the thorax.
• Right recurrent laryngeal n.
originates in the root of
neck.
• Enter the larynx deep to the
margin of the inferior
constrictor.
82. • Sinus of morgagni [ventricle of
larynx]
• Singer’s nodule
• Piriform fossa
