ANATOMY OF
LARYNX
MODERATOR: Dr.MANAS
PRESENTER:RAVINDRA.D
INTRODUCTION


The LARYNX is an
apparatus made up of
cartilage, ligaments,
muscles, and mucous
membrane, which
guards the...
DEVELOPMENT

OF LARYNX

Development of larynx
occur during the 4th
week of intra uterine life
 The respiratory
primordium...






The groove gradually
deepens and its edges
fuse to form a septum,
this septum separates
the laryngotracheal
tube ...






Between 5th & 6th weeks,
— 3 swellings
appear at the laryngeal
aditus.
An anterior swelling , a
derivative of the...


Laryngeal lumen— temporarily occluded at 8 weeks gestational
age as a result of epithelial proliferation.



By the 10...
EXTERNAL FEATURES










OF LARYNX

Larynx is located anterior to the
3rd, 4th, 5th, and 6th cervical
vertebrae.
E...
The carotid sheath and
its contents lie just
posterolateral to the
larynx.
 The recurrent laryngeal
nerve ascends in the
...
PRINCIPAL INTERNAL FEATURES OF THE LARYNX
The cavity of the larynx
extends
above – from the area
of the tip of the
epiglot...
INTERNAL CAVITY OF THE LARYNX
divided into 3 spaces:


Supraglottic,



Glottic, And



Subglottic spaces
DIFFERENCES BETWEEN ADULT & INFANT
LARYNX
7

S

1. Size- smaller in infants

2. Shape- funnel shaped in infants , cylindr...
Differences between adult & infant Larynx
Average measurements of larynx
SKELITAL ANATOMY
Laryngeal frame work consists of :
Cartilages
 Joints
 Ligaments
 Membranes
 Muscles
 Mucous membran...
HYOID












BONE

Described with the larynx
because of its anatomic
association with the
laryngeal apparatus...
ATTACHMENTS TO THE HYOID BONE















Medial end of the middle
constrictor muscle and the
stylohyoid ligamen...
SURGICAL CONSIDERATIONS
In tracheal resection and anastomosis, a tension-free
closure of the distal airway is essential.
...
During the excision of a
thyroglossal duct cyst,


excising the entire
tract along with the
central body of the
hyoid bon...
CARTILAGES OF LARYNX :















3
3

paired
unpaired

Paired :
Arytenoid
Corniculate
cunieform
Unpaired:
T...
THYROID CARTILAGE








located anterior to the
4th and 5th cervical
vertebrae.
formed by 2 laminae which
fuse ventr...










1.

2.
3.

Posterior border of each lamina
extends upward and downward
as hornlike projections,the
superio...
o











The thyrohyoid membrane and
median thyrohyoid ligament
are attached to the upper
border of the thyroid
...
SURGICAL CONSIDERATIONS
The thyroid cartilage is divided in the midline to
expose the endolarynx for various procedures
(f...
CRICOID CARTILAGE












Shaped like a signet ring.
signet-shaped portion of the
cricoid faces posteriorly
th...
Arising from the arch of
the cricoid cartilage
anteriorly and externally
are the cricothyroid
muscles.
 The lamina has a ...
SURGICAL CONSIDERATIONS










Injury to the cricoid cartilage from intubation or trauma
may result in perichondri...
ARYTENOID CARTILAGES













Almost pyramidal in
shape,
with
3 surfaces,
a base, and
an apex.
Each triangle-...


1.

2.

3.






Arytenoid has 3
surfaces
Posterior surface —
Transverse and oblique
arytenoid muscles attach
Media...
SURGICAL CONSIDERATIONS








Cricoarytenoid fixation may occur from arthritis or
perichondritis
(intubation
injury)...
CORNICULATE CARTILAGES ( OF SANTORINI )
small fibroelastic nodules
that sit on the apices of the
arytenoid cartilages.
 I...
TRITIATE
CARTILAGE
an occasional,
minute nodule.
 located in the
posterior margin of
the thyrohyoid
membrane

EPIGLOTTIS















Oblong leaf shaped
Located behind the root of the
tongue and the body of the hyoid
bon...
The space between the anterior surface of the
epiglottis and the thyrohyoid membrane and
thyroid cartilage is called the p...
SURGICAL CONSIDERATIONS
Acute epiglottiditis, may cause airway
obstruction in children.
 To rule out foreign bodies, a la...
LARYNGEAL LIGAMENTS

AND

MEMBRANES

Membranes — Extrinsic – Thyrohyoid membrane
Crico tracheal membrane
Intrinsic — Quadr...
LARYNGEAL MEMBRANES
THYROHYOID
MEMBRANE








provides an extensive
connection between the
thyroid cartilage and the...
SURGICAL CONSIDERATIONS
The superior laryngeal
neurovascular bundle
may be injured by
surgical approaches to
the pharynx.
...
THE CRICOTRACHEAL MEMBRANE



connects the most
superior tracheal
cartilage with the
inferior border of the
cricoid carti...
INTRINSIC MEMBRANES
connect the laryngeal
cartilages with each
other to regulate
movement.
 There are 2
intrinsic membran...
CONUS ELASTICUS
Conus Elasticus connects the
cricoid cartilage with the thyroid
and arytenoid cartilages.
 composed of de...
QUADRANGULAR MEMBRANE






Extends from the sides
of the epiglottic cartilage
anteriorly to the
anterolateral surface ...
The paired Quadrangular
Membranes connect the
epiglottis with the arytenoid
and thyroid cartilages.
 Course posteriorly d...
LIGAMENTS & FOLDS OF LARYNX


Epiglottic ligaments



Aryepiglottic fold





Vestibular ligament (vestibular folds or...
1 . EPIGLOTTIC LIGAMENTS
FOLDS


Hyoepiglottic ligament



Thyroepiglottic ligament



Median glossoepiglottic
ligament...
2 . ARYEPIGLOTTIC FOLDS






one on each side,
contain the aryepiglottic
muscles.
associated with the
superior border...
3 . VESTIBULAR FOLDS
(FALSE VOCAL CORDS)









formed by the inferior edge of
the quadrangular membrane.
Attached ...
4.VOCAL LIGAMENTS, VOCAL CORDS,
AND VOCAL FOLDS




The thickened,
ligamentous, upper
edges of the elastic
tissue of the...
STRUCTURE OF VOCALCORD











Histologically 5 layers:
LAYER 1: is the squamous epithelial lining. It is very ...










Vocalis muscle is infact a portion of
thyro arytenoid muscle.
At the anterior most portion of the vocal
fol...
RIMA GLOTTIDIS
Subdivided into 2 parts,




2/5 – intercartilaginous
part (respiratory
glottis,or interarytenoid
space),...
SURGICAL CONSIDERATIONS






The epithelium of the true vocal cords does not have
lymphatics. Therefore, metastatic di...
LARYNGEAL MUCOSA












Is mostly of the respiratory type called ciliated columnar
epithelium,

certain areas...
LARYNGEAL SPACES




o

o




Internal laryngeal
spaces :
vestibule,
ventricles,
subglottic or
infraglottic spaces
Ex...
INTERNAL SPACES (LARYNGEAL CAVITY)
VESTIBULE
 pyramid -shaped space
extends from the
laryngeal inlet or aditus
to the ves...
LARYNGEAL VENTRICLES








sinuses (of Morgagni), are
diverticula of the interval
between the false and true
vocal c...
SURGICAL CONSIDERATIONS.










Enlargement of the laryngeal
saccule is often referred to
as a laryngocele.
Any ob...
SUBGLOTTIC (INFRAGLOTTIC) SPACE








the distal part of the
laryngeal cavity.
extends from the glottis
to the infe...
EXTERNAL SPACES







Supraglottic laryngeal area is subdivided into 3
laryngeal spaces
Paired Lateral Paraglottic
One...
PARAGLOTTIC SPACES ( TUCKER’S
SPACE)
Bounded laterally by
the thyroid cartilage,
 inferomedially by the
conus elasticus,
...
PRE-EPIGLOTTIC SPACE ( BOAYER’S SPACE )







Bounded superiorly by the
hyoepiglottic ligament,
anteriorly by the thy...
SURGICAL CONSIDERATIONS
Epiglottic (supraglottic) carcinoma may spread
through perforations in the epiglottis into the
pre...
LARYNGEAL JOINTS








2 pairs of synovial joints
Between the major cartilages of the larynx:
the cricothyroid and
t...
1.CRICOTHYROID
JOINT








The joints between the
inferior cornua of the
thyroid cartilage and the
sides of the cric...
2.CRICOARYTENOID JOINT
 The crico-arytenoid joints
between articular facets on
the superolateral surfaces
of the cricoid ...
LARYNGEAL MUSCLES





Extrinsic muscles — which move the entire
larynx,

Intrinsic muscles — which move the vocal cords...
EXTRINSIC MUSCLES





ELEVATORS OF THE PHARYNX
The Suprahyoid Muscles
 Digastric
 Stylohyoid
 Mylohyoid
 Geniohyoi...
INTRINSIC MUSCLES










The intrinsic muscles
are:
Cricothyroid
Posterior cricoarytenoid
Lateral cricoarytenoid
...
MUSCLES CONTROLLING
INLET

Oblique arytenoid
 Aryepiglottic muscle


THE

LARYNGEAL
MOVEMENTS OF THE VOCAL CORDS
Adduction

Abduction

Glottis (space between folds)
Folds closed (adducted)

Folds open (ab...
ADDUCTORS
 Lateral

OF THE

VOCAL CORDS

cricoarytenoid
 Transverse arytenoid
ABDUCTOR OF THE VOCAL CORDS
Posterior

cricoarytenoid
MUSCLE INCREASING
THE VOCAL CORDS
 Cricothyroid:

THE

LENGTH & TENSION

increases the
distance between the angle of
the ...
MUSCLE DECREASING
VOCAL CORDS

 Thyroarytenoid

THE

(vocalis): pulls the
arytenoid cartilage
forward toward the
thyroid ...
SPHINCTERIC FUNCTION OF THE
LARYNX
There are two sphincters:
 At the inlet: used only
during swallowing
 At the rima glo...
SHAPE OF GLOTTIS
Quiet Respiration

Forced Inspiration
INSPIRATION
SHAPE OF GLOTTIS
Normal voice

Whisper
NORMAL PHONATION
WHISPER
BLOOD SUPPLY OF LARYNX :
ARTERIAL SUPPLY
 Upper Larynx
 External carotid artery
 Superior thyroid artery
 Superior lar...
VENOUS
DRAINAGE
Upper Larynx
 Superior laryngeal
vein
 Superior thyroid vein
 Internal jugular vein


Lower Larynx
 I...
LYMPHATIC DRIANAGE
SUPRA GLOTTIC AREA
superior lymphatics drain to
the upper deep cervical
nodes, located at the level of
...
 GLOTIC AREA ( VOCAL FOLDS) is relatively
devoid of lymphatics.




The space deep to the thin mucosa of the true vocal...
SURGICAL IMPORTANCE








Elective dissection of node
levels II to IV for N-0
laryngeal and hypopharyngeal
carcinoma...
NERVE SUPPLY



1.
2.








Supplied by Vagus nerve:
Superior laryngeal nerve
Internal branch (sensory) –
areas a...
BIBLIOGRAPHY
SCOTT&BROWN 6TH EDITION
 GRAY’S ANATOMY 40TH EDITION
 THE LARYNX -HUGH D. CURTIN

THANK YOU…
anatomy of larynx by ravindra daggupati
anatomy of larynx by ravindra daggupati
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anatomy of larynx by ravindra daggupati

  1. 1. ANATOMY OF LARYNX MODERATOR: Dr.MANAS PRESENTER:RAVINDRA.D
  2. 2. INTRODUCTION  The LARYNX is an apparatus made up of cartilage, ligaments, muscles, and mucous membrane, which guards the entrance to the lower respiratory passages (trachea, bronchi, and lungs) and houses the vocal cords.
  3. 3. DEVELOPMENT OF LARYNX Development of larynx occur during the 4th week of intra uterine life  The respiratory primordium appears in the floor of the foregut in the 4th week of gestational life.  The larynx begins as a slit like diverticulum(laryngotrac heal groove ) in the ventral wall of the primitive pharynx . 
  4. 4.    The groove gradually deepens and its edges fuse to form a septum, this septum separates the laryngotracheal tube from the pharynx and oesophagus. The process of this fusion starts caudally and extend cranially
  5. 5.    Between 5th & 6th weeks, — 3 swellings appear at the laryngeal aditus. An anterior swelling , a derivative of the hypobranchial eminence from 4th arch—forms Epiglottis. 2 lateral arytenoid swellings appear, derived from the 6th branchial arch, move medially and form a T-shaped aperture
  6. 6.  Laryngeal lumen— temporarily occluded at 8 weeks gestational age as a result of epithelial proliferation.  By the 10th week of gestation, recanalization occurs and consequently pair of laryngeal ventricles are formed.  The laryngeal ventricles are bound by mesenchyme tissue that condense and progress into false and true vocal cords.  Laryngeal cartilages develop from the mesenchyme of the branchial arches.  Thyroid cartilage-- from the 4th arch mesenchyme as two lateral plates meet in the midline.    Arytenoids , Corniculate , Cricoid & Tracheal cartilages-- 6th branchial arch Epiglottis — develops from Hypobranchial eminence Intrinsic laryngeal muscles develop from the mesoderm of the 4th and 6th arches
  7. 7. EXTERNAL FEATURES      OF LARYNX Larynx is located anterior to the 3rd, 4th, 5th, and 6th cervical vertebrae. Extends from the base of the tongue to the proximal portion of the trachea. Laryngeal skeleton is suspended from the hyoid bone by the medial and lateral thyrohyoid membrane. The lateral lobes of the thyroid gland lie anterolateral to the thyroid and cricoid cartilage. Isthmus of the thyroid gland lies just below the cricoid cartilage and often covers the first 1 or 2 tracheal rings.
  8. 8. The carotid sheath and its contents lie just posterolateral to the larynx.  The recurrent laryngeal nerve ascends in the tracheoesophageal groove and enters the larynx just posterior to the cricothyroid articulation  The 3rd to 6th cervical vertebrae, prevertebral muscles, and fascia lie posterior to the larynx. 
  9. 9. PRINCIPAL INTERNAL FEATURES OF THE LARYNX The cavity of the larynx extends above – from the area of the tip of the epiglottis,aryepiglotti c folds, and interarytenoid folds below — to the 1st tracheal ring
  10. 10. INTERNAL CAVITY OF THE LARYNX divided into 3 spaces:  Supraglottic,  Glottic, And  Subglottic spaces
  11. 11. DIFFERENCES BETWEEN ADULT & INFANT LARYNX 7 S 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
  12. 12. Differences between adult & infant Larynx
  13. 13. Average measurements of larynx
  14. 14. SKELITAL ANATOMY Laryngeal frame work consists of : Cartilages  Joints  Ligaments  Membranes  Muscles  Mucous membrane  + Hyoid Bone 
  15. 15. HYOID         BONE Described with the larynx because of its anatomic association with the laryngeal apparatus. located in front of the 3rd cervical vertebra. serves as an attachment for the larynx via the thyrohyoid membrane and the extrinsic muscles of the larynx. The hyoid bone is suspended from the skull base (temporal bone) via the stylohyoid ligaments It is an U-shaped bone with Body 2 lesser horns (cornua) 2 greater horns (cornua)
  16. 16. ATTACHMENTS TO THE HYOID BONE        Medial end of the middle constrictor muscle and the stylohyoid ligament attach to the lesser cornu. The middle constrictor and hyoglossus muscles attach to the greater cornu. geniohyoid and genioglossus attaches to the inner and upper surfaces of the body of the hyoid bone. The mylohyoid attaches to the anterior surface of the hyoid. The tendon of the digastric muscle attaches to the anterolateral portion of the body. sternohyoid, omohyoid, and thyrohyoid attaches to the inferior surface of body. Each muscle acts to depress the hyoid bone.
  17. 17. SURGICAL CONSIDERATIONS In tracheal resection and anastomosis, a tension-free closure of the distal airway is essential.  The larynx can be released and "dropped" from the hyoid bone to reduce tension on the distal suture line.  This is accomplished by detaching the infrahyoid muscles from the inferior surface of the hyoid bone body and cutting the hyoid bone just lateral to the lesser cornua  This releases the central body of the hyoid and larynx.  Additional relaxation can be achieved by cutting the suspensory ligament of the superior cornu of the thyroid cartilage  This can lower the larynx to a maximum of 4.5 cm.  The hyoid bone serves as a site of access to the supraglottic larynx and pharynx. 
  18. 18. During the excision of a thyroglossal duct cyst,  excising the entire tract along with the central body of the hyoid bone (Sistrunk procedure) reduces the recurrence rate.
  19. 19. CARTILAGES OF LARYNX :           3 3 paired unpaired Paired : Arytenoid Corniculate cunieform Unpaired: Thyroid Cricoid Epiglottic
  20. 20. THYROID CARTILAGE     located anterior to the 4th and 5th cervical vertebrae. formed by 2 laminae which fuse ventrally in the midline of the neck, forming a protuberance, the laryngeal prominence or "Adam's apple,― The 2 laminae meet at an angle of 90° in the male and 120° in the female. The upper limit of fusion of the two laminae forms the superior thyroid notch
  21. 21.       1. 2. 3. Posterior border of each lamina extends upward and downward as hornlike projections,the superior and inferior cornua The cornua are characterized further at their origins from the thyroid laminae by superior and inferior tubercles. Both of the superior horns are anchored to the tips of the greater horns of the hyoid bone; both inferior horns articulate with the cricoid cartilage. On the lateral, external surface of each thyroid lamina is—ridge ,called the oblique line, attaches to 3 muscle Sternothyroid, Thyrohyoid,and Thyropharyngeus (a portion of the inferior pharyngeal constrictor).
  22. 22. o       The thyrohyoid membrane and median thyrohyoid ligament are attached to the upper border of the thyroid cartilage. The lateral thyrohyoid ligaments attach to the greater cornua of the thyroid cartilage. The cricothyroid ligaments (cricothyroid membrane) attach to the inferior border of the thyroid cartilage 5 ligaments attach as one to the posterior surfaces of the thyroid laminae near the union of the laminae (angle): The median thyroepiglottic ligament, The 2 vestibular ligaments,And The 2 vocal ligaments.
  23. 23. SURGICAL CONSIDERATIONS The thyroid cartilage is divided in the midline to expose the endolarynx for various procedures (for example, partial laryngectomy, laryngotracheoplasty, and arytenoidectomy).  The vocalis muscle and vocal ligaments attach to the inner surface of the thyroid cartilage at the anterior commissure  On the external laryngeal surface in adult males this point is halfway between the thyroid notch and the inferior border of the thyroid cartilage. It is slightly higher in adult females.  In many laryngofissure approaches, it may be beneficial to stay below the midpoint in order to avoid dividing the anterior commissure. 
  24. 24. CRICOID CARTILAGE         Shaped like a signet ring. signet-shaped portion of the cricoid faces posteriorly the arch is located anteriorly, The cricoid cartilage is situated at vertebral level C6 (occasionally reaching the middle of C6), just below the thyroid cartilage The cricoid lamina has 2 superior facets– articulate with the arytenoid cartilages and attach to them by the posterior cricoarytenoid ligaments 2 lower lateral facets of the lamina articulate with the inferior horns of the thyroid cartilage. The lower border of the cricoid cartilage is joined to the first tracheal ring by means of the thick cricotracheal ligament.
  25. 25. Arising from the arch of the cricoid cartilage anteriorly and externally are the cricothyroid muscles.  The lamina has a midline ridge for the tendinous attachment of longitudinal fibers of the esophagus.  Lateral to this ridge are the sites of origin for the bilateral posterior cricoarytenoid muscles. 
  26. 26. SURGICAL CONSIDERATIONS      Injury to the cricoid cartilage from intubation or trauma may result in perichondritis and lead to subglottic stenosis. Surgical approaches to repair long-standing subglottic stenosis involve the expansion of the circumference of the cricoid ring with autologous cartilage grafts. Tracheotomies are usually performed at least one tracheal ring below the cricoid cartilage (2nd or 3rd tracheal ring) to avoid subglottic stenosis. During an emergency cricothyroidotomy, the tracheostomy tube is inserted through the median cricothyroid ligament — the quickest and easiest access to the airway. To avoid permanent laryngeal stenosis — cricothyroidotomy must be converted to a standard tracheotomy within days.
  27. 27. ARYTENOID CARTILAGES          Almost pyramidal in shape, with 3 surfaces, a base, and an apex. Each triangle-shaped base articulates with the cricoid cartilage by way of a diarthrodial joint. Base has 2 processes: Anteromedially directed vocal process – vocal ligament is attached Short, broad, laterally projecting Muscular process – lateral and posterior cricoarytenoid muscles are attached
  28. 28.  1. 2. 3.     Arytenoid has 3 surfaces Posterior surface — Transverse and oblique arytenoid muscles attach Medial surface – covered with mucous-secreting laryngeal mucosa. Anterolateral surface – insertion of thyroarytenoid muscle, part of the vocalis muscle,and the vestibular ligament. The apex of the arytenoid cartilage supports the corniculate cartilage
  29. 29. SURGICAL CONSIDERATIONS     Cricoarytenoid fixation may occur from arthritis or perichondritis (intubation injury) and limit vocal fold mobility. Cricoarytenoid subluxation during blind intubation with a lighted stylet. Arytenoidectomy through an external or endoscopic approach may alleviate arytenoid fixation or paralysis. submucosal arytenoidectomy which preserves an intact laryngeal mucosa
  30. 30. CORNICULATE CARTILAGES ( OF SANTORINI ) small fibroelastic nodules that sit on the apices of the arytenoid cartilages.  It has little functional importance in humans   CUNEIFORM CARTILAGES (OF WRISBERG) rod-shaped (like ancient cuneiform script).  situated in the aryepiglottic folds anterior to the corniculate cartilages,  may be entirely absent. 
  31. 31. TRITIATE CARTILAGE an occasional, minute nodule.  located in the posterior margin of the thyrohyoid membrane 
  32. 32. EPIGLOTTIS           Oblong leaf shaped Located behind the root of the tongue and the body of the hyoid bone and in front of the laryngeal entrance (laryngeal aditus or vestibule). It has: 2 ends— upper & Lower 2 surfaces— Anterior & Posterior 2 Lateral borders Upper end:broad lower end: narrow –― petiolus / stalk ‖ attaches to inner surface of thyroid cartilage below thyroid notch by the thyroepiglottic ligament It attaches to the posterior body of the hyoid bone via the hyoepiglottic ligament it lies dorsal to the thyroid cartilage and thyrohyoid membrane, guarding the laryngeal entrance.
  33. 33. The space between the anterior surface of the epiglottis and the thyrohyoid membrane and thyroid cartilage is called the preglottic space  The epiglottis is attached to the thyroid cartilage by the thyroepiglottic ligament.  The aryepiglottic folds and the quadrangular membranes attach to the lower part of the lateral margins of the epiglottis. 
  34. 34. SURGICAL CONSIDERATIONS Acute epiglottiditis, may cause airway obstruction in children.  To rule out foreign bodies, a lateral x-ray may be ordered if the general condition of the child permits.  Laryngeal visualization must be done in the operating room to avoid airway occlusion, aspiration, and cardiac arrest.  Intubation and tracheostomy are the procedures of choice 
  35. 35. LARYNGEAL LIGAMENTS AND MEMBRANES Membranes — Extrinsic – Thyrohyoid membrane Crico tracheal membrane Intrinsic — Quadrangular membrane Conus elasticus Ligaments & Folds  Epiglottic ligaments  Aryepiglottic fold  Vestibular ligament (vestibular folds or false vocal cords)  Vocal ligaments 
  36. 36. LARYNGEAL MEMBRANES THYROHYOID MEMBRANE     provides an extensive connection between the thyroid cartilage and the hyoid bone bilaterally and anteriorly. Extending from the upper border and the greater horns of the hyoid bone to the superior horns of the thyroid cartilage and its laminae Thickens anteriorly, forming the median thyrohyoid ligament Thickened posterior margin on each side is called the lateral thyrohyoid ligament.
  37. 37. SURGICAL CONSIDERATIONS The superior laryngeal neurovascular bundle may be injured by surgical approaches to the pharynx.  One must observe great care when dissecting the greater cornu of the hyoid bone and the superior horn of the thyroid cartilage during various pharyngotomy approaches 
  38. 38. THE CRICOTRACHEAL MEMBRANE  connects the most superior tracheal cartilage with the inferior border of the cricoid cartilage
  39. 39. INTRINSIC MEMBRANES connect the laryngeal cartilages with each other to regulate movement.  There are 2 intrinsic membranes : 1. Conus Elasticus and 2. Quadrangular membranes. 
  40. 40. CONUS ELASTICUS Conus Elasticus connects the cricoid cartilage with the thyroid and arytenoid cartilages.  composed of dense fibroconnective tissue with abundant elastic fibers.  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 membrane. 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 
  41. 41. 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
  42. 42. 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. 
  43. 43. LIGAMENTS & FOLDS OF LARYNX  Epiglottic ligaments  Aryepiglottic fold   Vestibular ligament (vestibular folds or false vocal cords) Vocal ligaments
  44. 44. 1 . EPIGLOTTIC LIGAMENTS 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 AND
  45. 45. 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.
  46. 46. 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.
  47. 47. 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.
  48. 48. 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.
  49. 49.      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
  50. 50. RIMA GLOTTIDIS Subdivided into 2 parts,   2/5 – intercartilaginous part (respiratory glottis,or interarytenoid space), between the arytenoid cartilages and 3/5 — the intermembranous part or glottis vocalis.
  51. 51. 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.
  52. 52. 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.
  53. 53. LARYNGEAL SPACES    o o   Internal laryngeal spaces : vestibule, ventricles, subglottic or infraglottic spaces External laryngeal spaces Paraglottic space pre-epiglottic. Space
  54. 54. 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.
  55. 55. LARYNGEAL VENTRICLES     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, This extends upward deep to the internal face of the thyroid cartilage.
  56. 56. 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
  57. 57. 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
  58. 58. EXTERNAL SPACES    Supraglottic laryngeal area is subdivided into 3 laryngeal spaces Paired Lateral Paraglottic One midline Pre-Epiglottic Spaces Space
  59. 59. PARAGLOTTIC SPACES ( TUCKER’S SPACE) Bounded laterally by the thyroid cartilage,  inferomedially by the conus elasticus,  medially by the ventricle and the quadrangular membrane 
  60. 60. 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.
  61. 61. 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 
  62. 62. LARYNGEAL JOINTS     2 pairs of synovial joints Between the major cartilages of the larynx: the cricothyroid and the cricoarytenoid.
  63. 63. 1.CRICOTHYROID JOINT     The joints between the inferior cornua of the thyroid cartilage and the sides of the cricoid cartilage are synovial The primary movement at the joint is rotation around a transverse axis which passes transversely through both cricothyroid joints The effect of these movements is to lengthen the vocal folds, provided the arytenoid cartilages are stabilized at the cricoarytenoid joint. This may also increase vocal fold tension
  64. 64. 2.CRICOARYTENOID JOINT  The crico-arytenoid joints between articular facets on the superolateral surfaces of the cricoid cartilage and the bases of the arytenoid cartilages enable the arytenoid cartilages to slide away or towards each other and to rotate so that the vocal processes pivot either towards or away from the midline. These movements abduct and adduct the vocal ligaments 3.ARYTINOCORNICULATE JOINT  Synovial or cartilaginous joints link the arytenoid and corniculate cartilages
  65. 65. LARYNGEAL MUSCLES   Extrinsic muscles — which move the entire larynx, Intrinsic muscles — which move the vocal cords.
  66. 66. EXTRINSIC MUSCLES    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
  67. 67. INTRINSIC MUSCLES       The intrinsic muscles are: Cricothyroid Posterior cricoarytenoid Lateral cricoarytenoid Arytenoid with its transverse and oblique fibers Thyroarytenoid and its thyroepiglottic and components
  68. 68. MUSCLES CONTROLLING INLET Oblique arytenoid  Aryepiglottic muscle  THE LARYNGEAL
  69. 69. MOVEMENTS OF THE VOCAL CORDS Adduction Abduction Glottis (space between folds) Folds closed (adducted) Folds open (abducted) (View from above)
  70. 70. ADDUCTORS  Lateral OF THE VOCAL CORDS cricoarytenoid  Transverse arytenoid
  71. 71. ABDUCTOR OF THE VOCAL CORDS Posterior cricoarytenoid
  72. 72. MUSCLE INCREASING THE VOCAL CORDS  Cricothyroid: THE LENGTH & TENSION 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 OF
  73. 73. MUSCLE DECREASING VOCAL CORDS  Thyroarytenoid THE (vocalis): pulls the arytenoid cartilage forward toward the thyroid cartilage and thus shortens and relaxes the vocal cords LENGTH & TENSION OF
  74. 74. 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
  75. 75. SHAPE OF GLOTTIS Quiet Respiration Forced Inspiration
  76. 76. INSPIRATION
  77. 77. SHAPE OF GLOTTIS Normal voice Whisper
  78. 78. NORMAL PHONATION
  79. 79. WHISPER
  80. 80. 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 
  81. 81. VENOUS DRAINAGE Upper Larynx  Superior laryngeal vein  Superior thyroid vein  Internal jugular vein  Lower Larynx  Inferior laryngeal vein  Inferior thyroid vein  subclavian vein 
  82. 82. LYMPHATIC DRIANAGE SUPRA GLOTTIC AREA superior lymphatics drain to the upper deep cervical nodes, located at the level of the carotid bifurcation.  Some drainage passes to prelaryngeal nodes.  INFRA GLOTTIC AREA drain to the pretracheal lymph nodes of the proximal trachea anteriorly paratracheal nodes laterally and then to the deep cervical and superior mediastinal nodes. 
  83. 83.  GLOTIC AREA ( VOCAL FOLDS) is relatively devoid of lymphatics.   The space deep to the thin mucosa of the true vocal cords, which is called Reanke's space, has no direct lymphatic drainage. The spread of carcinoma is, likewise and fortunately, retarded until an invasive process involves tissue peripheral to the true vocal cord.  DELPHIAN  NODE : a midline prelaryngeal lymph node, adjacent to the thyroid gland, enlargement of which is indicative of metastasis from thyroid or laryngeal carcinoma.
  84. 84. SURGICAL IMPORTANCE     Elective dissection of node levels II to IV for N-0 laryngeal and hypopharyngeal carcinoma, Bilateral selective dissection is justified by the prevalence of bilateral metastases in midline and bilateral tumors. The superior neurovascular bundle may be injured during anterior and lateral pharyngotomy approaches to the larynx. Branches of the cricothyroid artery may be accidentally injured during emergency cricothyroidotomy.
  85. 85. NERVE SUPPLY   1. 2.      Supplied by Vagus nerve: Superior laryngeal nerve Internal branch (sensory) – areas above the glottis External branch (motor and sensory) Motor – Cricothyroid muscle Sensory – Anterior infraglottic larynx at level of cricothyroid membrane Inferior (recurrent) laryngeal n. Motor – all intrinsic laryngeal muscles of SAME side (except cricothyroid) and interarytenoid muscle of BOTH sides Sensory – areas below the glottis
  86. 86. BIBLIOGRAPHY SCOTT&BROWN 6TH EDITION  GRAY’S ANATOMY 40TH EDITION  THE LARYNX -HUGH D. CURTIN 
  87. 87. THANK YOU…

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