Describes in-depth anatomy of larynx for mbbs and pg students.

1. Anatomy of larynx
• Dr ARSHAQUE HUSSAIN
• DNB 1ST YEAR
• DEPARTMENT OF ENT
• GMSH 16, CHANDIGARH

2. CONTENTS
• INTRODUCTION AND HISTORY
• EMBRYOLOGY
• LARYNGEAL FRAMEWORK
• CAVITY OF LARYNX
• JOINTS
• SPACES WITHIN LARYNX
• BLOOD AND NERVE SUPPLY OF LARYNX
• PAEDIATRIC LARYNX

3. INTRODUCTION AND HISTORY
• LARYNX protects the lower respiratory tract, provides a controlled airway, allows
phonation & allows generation of high intrathoracic pressure for coughing and lifting.
• The ability of LARYNX to facilitate speech is only found in humans.
• To fulfil its complex functions, it has to be mobile, coordinated and sensate.
• In 1743, LEVERETT attempted to examine the throat with a bent mirror.
• In 1807, Dr. BENJAMIN GUY BABINGTON presented the first LARYNGOSCOPE to
HUNTERIAN SOCIETY in London.
• FATHER OF LARYNGOLOGY - MANUEL GARCIA.

4. Also called as GLOTTISCOPE.

5. “The manner in which the glottis silently opened and shut and moved in the act of phonation, filled
me with wonder.”
- MANUEL GARCIA, The Inventor of LARYNGOSCOPE and A WORLD RENOWNED
SINGING TEACHER.

6. EMBRYOLOGY OF LARYNX
• LARYNX extends from laryngeal inlet to inferior border of cricoid cartilage.
• In absence of respiration at neutral lung volume, it lies front of C3 to C6 vertebra,a little
higher in women than in men.
• DERIVATIVES: INTERNAL LINING OF LARYNX - ENDODERM
• DERIVATIVES: CARTILAGES AND MUSCLES – MESENCHYME OF 4TH AND
6th PHARYNGEAL ARCHES.

7. ARCH NERVE BLOOD SUPPLY SKELETAL
DERIVATIVES
MUSCLE
DERIVATIVES
3RD ARCH GLOSSOPHARYNGEAL
NERVE
CCA
PROXIMAL ICA
GREATER CORNU
OF HYOID
LOWER Part of
HYOID body
Stylopharyngeus
4th ARCH SUPERIOR
LARYNGEAL NERVE
OF VAGUS
RIGTH: RIGHT SCA
LEFT: ARCH OF
AORTA
THYROID
CARTILAGE
CORNICULATE
CARTILAGE
CUNEIFORM
CARTILAGE
CRICOTHYROID
6TH ARCH RECURRENT
LARYNGEAL NERVE
OF VAGUS
RIGHT: RIGHT
PULMONARY
ARTERY
LEFT: LEFT
PULMONARY
ARTERY
ARYTENOID
CARTILAGE
ALL INTRINSIC
MUSCLES OF
LARYNX EXCEPT
CRICOTHYROID

8. • Rapid proliferation of mesenchyme
results slit shape laryngeal inlet to
Tshaped. Further mesenchym forms
THYROID, CRICOID and
ARYTENOID CARTILAGE and
give characteristic adult shape.
• When mesenchyme of the two arches
transforms into the THYROID,
CRICOID, AND ARYTENOID
CARTILAGES, the characteristic
adult shape of the laryngeal orifice can
be recognised.

9. At about the time the cartilages are formed, the laryngeal epithelium also proliferates rapidly,
causing temporary occlusion of the lumen.
Subsequently vacuolisation and recanalisation produce a pair of lateral recesses called
LARYNGEAL VENTRICLES.
These recesses are bounded by folds of tissue that differentiate into FALSE and TRUE
vocal cords.
STRUCTURES DERIVED FROM DERIVED FROM
SUPRAGLOTTIS BUCCOPHARYNGEAL
PRIMORDIUM
3RD AND 4TH
PHARYNGEAL ARCH
GLOTTIS AND
SUBGLOTTIS
TRACHEOBRONCHIAL
PRIMORDIUM
6TH PHARYNGEAL
ARCH

10. EMBRYOLOGICAL IMPORTANCE
• Embryological development of larynx determines the pattern of metastatic spread of
laryngeal cancer
• Conservational laryngeal surgery- basis of the THEORY OF SUBMUCOSAL
COMPARTMENTALISATION of larynx, evolved from the work of Frazer, Pressman
and colleagues, and Tucker and Smith.
• Pressman found that this separate embryological derivation explains why
SUPRAGLOTTC Tumors of substantial bulk do not spread across the laryngeal ventricle
to the vocal cord.
• On experiments, submucosal vital dyes and radioisotopes injection, noted that the inferior
extent of supraglottic injection was the inferior false vocal cord. The ventricle was an
anatomical barrier to the inferior flow of the dye and thus was confirmed as a barrier to
Tumor spread.

11. LARYNGEAL FRAMEWORK
• TOPICS OF DISCUSSION :
• HYOID BONE
• CARTILAGES
• MEMBRANES AND LIGAMENTS
• MUSCLES

12. HYOID BONE

13. Development and Ossification
Lesser cornua 2nd arch
Greater cornua 3rd arch
Ossification centres of HYOID BONE : 6, A pair for the body, 2 greater cornua and 2
lesser cornua.
Ossification starts in greater cornu at the end of fetal life- to body- to lesser cornu by 1-2
year after birth.

14. Muscles attached to hyoid bone
• GENIOHYOID is attached to most of the anterior surface of the body, above and below
the transverse ridge.
• MEDIAL PART OF HYOGLOSSUS invades the lateral geniohyoid area.
• MYLOHOID attaches to lower anterior surface.
• LOWEST FIBRES OF GENIOGLOSSUS, HYOEPIGLOTTIC LIGAMENT AND
(MOST POSTERIORLY) THYROHYOID MEMBRANE are all attached to the
rounded superior border.
• STERNOHYOID is attached to the inferior border medially and OMOHYOID is attached
laterally.

16. LARYNGEAL CARTILAGES
• 3 PAIRED:
• ARYTENOID CARTILAGE
• CORNICULATE CARTILAGE AKA CARTILAGE OF SANTORINI.
• CUNEIFORM CARTILAGE AKA CARTILAGE OF WRISBERG.
• 3 UNPAIRED:
• THYROID CARTILAGE
• CRICOID CARTILAGE
• EPIGLOTTIS
• CARTILAGES OF LUSCHKA: these are acessesory cartilages, may be variable present,
may include the TRITICEAL( in the lateral thyrohyoid ligaments), the interarytenoid, and a
small caartilage sometimes found within vocal ligament of the vocal folds.

17. Histology and Ossification of laryngeal cartilages
•HYALINE cartilage can undergo ossification, which begins at THYROID at 25 years> CRICOID AND ARYTENOID >
COMPLETES BY 65 YEARS
•Calcification of posterior part of cricoid and ARYTENOID cartilages can be confused with foreign body on x ray.
HYALINE
CARTILAGE
ELASTIC
FIBROCARTILAGE
THYROID
CRICOID
MOST OF
ARETENOID
EPIGLOTTIS
CORNICULATE
CUNEIFORM
TIP OF ARYTENOID

18. THYROID CARTILAGE
• SHEILD LIKE(GREEK)
• Largest laryngeal cartilage
• 2 lamina fused in the midline superiorly forming THYROID NOTCH.
• ANGLE OF FUSION is about 90 degree in men and 120 degree in women.
• Fused anterior border forms a projection k/a LARYNGEAL PROMINENCE OR ADAM’S
APPLE. Also called MALE BUMP.
• Posteriorly the lamina diverge. Superiorly curves upward, backward and medially forming
SUPERIOR CORNUA -LATERAL THYROID LIGAMENT ATTACHES TO IT.
• Inferiorly curves downward and medially forming INFERIOR CORNUA- CONTAINS
SMALL FACET FOR ARTICULATION OF CRICOID.

21. Muscles attachment to thyroid cartilage
• Inner aspect is loosely attached to mucous membrane.
• Just below the thyroid notch in the midline is the attachment of Thyroepiglottic ligament.
Below this on each side of the midline is vestibular and vocal ligament.
• Superior border of thyroid cartilage gives attachment to thyrohoid membrane.
• Inferior border gives attachment to CRICOTHYROID MEMBRANE.
• On external surface, oblique line is present downward and forward from superior thyroid
tubercle to inferior thyroid tubercle. This gives attachment to THYROHYOID,
STERNOTHYROID and INFERIOR CONSTRICTOR.

22. Extension of cancer
• The extension of cancer into the thyroid cartilage tends to occur in areas of ossification of
the cartilage.
• MODE OF INVASION INTO OSSIFIED BONE :
• 1.OSTEOCLAST FORMATION.
• 2.EXTENSION ALONG COLLAGEN BUNDLES.
• 3.THROUGH AREAS OF HIGH VASCULARITY.
• MOST COMMON SITE OF INVASION OF THYROID CARTILAGE – angle of thyroid
cartilage, others : points of attachment of CRICOTHYROID membrane and the anterior
origin of the thyroarytenoid musculature.
• Although the perichondrium is an excellent barrier to invasion, but once the carcinoma is
within the cartilage, the cancer can extend throughout the cartilage behind the intact
perichondrium.

23. CRICOID
CARTILAGE
• The cricoid cartilage is the only complete
cartilaginous ring in the airway.
• It forms the inferior part of the anterior and
lateral walls and most of the posterior wall
of the larynx
• It has a deep broad lamina posteriorly and a
narrow arch anteriorly with a facet for
articulation with the inferior cornu of the
thyroid cartilage, near the junction of the
arch and lamina.
• The lamina has sloping shoulders on which
the articular facets for the arytenoid
cartilages are found.

24. Attachments to CRICOID CARTILAGE
• The vertical ridge in the midline of lamina gives attachment to longitudinal muscle of
esophagus and produces a shallow con cavity on each side for attachment of posterior
cricoarytenoid muscle.
• Entire inner surface is lined by mucous membrane. This mucosa is at risk of necrosis and
circumferential scarring, which leads to debilitating subglottic stenosis.
• Most common site of cricoid cartilage invasion by carcinoma is at its posterior superior
border.

25. EPIGLOTTIS
• Its leaf like, yellow elastic cartilage which forms anterior wall of laryngeal inlet.
• Projects upward and behind the tongue and the body of hyoid bone.
• Attached to hyoid bone by hyoepiglottic ligament dividing it into supra hyoid and
infrahyopid parts.
• Petiole which is stalk like process attaches to below thyroid notch by thyroepiglottic
ligament.
• From the sides aryepiglottic folds pass down to the apex of ARYTENOIDs.
• The anterior (lingual) surface of the epiglottis is covered with mucous membrane
superiorly and forms the posterior wall of the vallecula. The mucous membrane overlying
the epi- glottis is reflected onto the base of the tongue, forming the glossoepiglottic fold in
the midline and laterally the lateral glossoepiglottic folds.

26. •Posterior surface of epiglottis has numerous pits into which mucous glands projects. This is a
weak area where Tumor from posterior surface perforates to other side.

27. ARYTENOID
CARTILAGE
• Means LADLE(Greek) = means form
• It’s an irregular three sided pyramidal
structure, irregular, placed closed together
on upper and lateral border of cricoid
lamina.
• Most common site of ARYTENOID
invasion is at the points of attachment of the
joint capsule.

28. •Three surfaces : posterior, medial,
anterolateral
•Two fossa on anterolateral surface :
upper triangular fossa – vestibular
ligament and lower fossa - vocalis and
lateral cricoarytenoid.
•Two projections : the vocal process
and the muscular process
•Apex of the cartilage curved medially,
backwards and flattened for articulation
with CORNICULATE cartilage.

29. Muscles attached to muscular process-
1. POSTERIOR CRICOARYTENOID
2. LATERAL CRICOARYTENOID
CRICOAREYTENOID JOINT:
Base is concave forming joint with
cricoid lamina.
SYNOVIAL JOINT
MOVEMENTS :
1. SLIDING IN DORSOVENTRAL
AXIS
2. SLIDING IN LATERAL-
MEDIAL AXIS
3. ROTATION ABOUT THE
CRANIOCAUDAL AXIS
These movements affect the positions of the
vocal process, and therefore the attached vocal
folds.

30. CORNICULATE
CARTILAGE
• Aka CARTILAGE OF
SANTORINI, it’s horn shaped,
small conical nodular elastic
fibrocartilage.
• Articulates through a synovial
joint with apices of arytenoid,
sometimes fused
• Present in posterior part of
aryepiglottic fold

31. CUNEIFORM
CARTILAGE
• Cartilage of Wrisberg• Two small
elongated flakes of fibro-elastic
cartilages (rod shaped) one in
each margin of Aryepiglottic
fold• Present in front of
Corniculate cartilage and provide
passive support to the fold

32. MEMBRANES And LIGAMENTS
•
EXTRINSIC :
When attaches to structures outside
the larynx i.e, HYOID, TRACHEA
INTRINSIC: When attaches within
but not extending to HYOID,
TRACHEA
1. THYROHYOID
MEMBRANE: pierced by superior
laryngeal vessels and internal
laryngeal nerve
1. CRICOVOCAL MEMBRANE
2. CRICOTRACHEAL MEMBRANE:
cricoid to 1st tracheal ring
2. QUADRANGULAR MEMBRANE
3. HYOEPIGLOTTIC LIGAMENT 3. CRICOTHYROID MEMBRANE
4. THYROEPIGLOTTIC LIGAMENT

33. CRICOVOCAL
membrane

34. QUADRANGULAR
MEMBRANE

35. THYROEPIGLOTTIC
LIGAMENT

36. MUSCLES OF LARYNX
EXTRINSIC INTRINSIC
ELEVATORS. DEPRESSORS. ACTING ON
VOCAL CORD
ACTING ON
LARYNGEAL
INLET

37. PRIMARY ELEVATORS SECONDARY
ELEVATORS
STYLOPHARYNGEUS MYLOHYOID
SALPINGOPHARYNGE
US
DIGASTRIC
PALATOPHARYNGEUS STYLOHYOID
THYROHYOID GENIOHYOID
ELEVATORS DEPRESSORS
STERNOHYOID
STERNOTHYROID
OMOHYOID

38. ABDUCTORS POSTERIOR
CRICOARYTENOID
ADDUCTORS LATERAL
CRICOARYTENOID,
THYROARTENOID
external part,
TRANSVERSE
ARYTENOID
TENSORS CRICOTHYROID,
VOCALIS
OPENERS THYROEPIGLOTT
IS
CLOSERS OBLIQUE INTER
ARYTENOID,
ARYEPIGLOTTIS
ACTING ON VOCAL CORDS ACTING ON LARYNGEAL
INLET

39. ORIGIN Medial aspect of styloid
process, gap between
middle and superior
constrictor
INSERTION Posterior border of thyroid
cartilage
NERVE SUPPLY GLOSSOPHARYNGEAL
nerve
Stylopharyngeus

40. SALPINGOPHARYNGEUS
ORIGIN Pharyngeal part of
eustachian tube
INSERTION Blend with
palatopharyngeus
NERVE SUPPLY Cranial part of accessory
nerve

41. PALATOPHARYNGEUS
ORIGIN Hard palate and
palatine aponeurosis
INSERTION Lateral wall of pharynx
NERVE SUPPLY Pharyngeal plexus

42. Secondary elevators
• 1) MYLOHOID: it’s a flat, triangular sheet attached to the whole length of the mylohyoid
line of the mandible- along the mylohyoid line ending before the lower 3rd molar tooth.
• Insertion: lower border of hyoid
• Blood supply: SUBLINGUAL BRANCH OF LINGUAL ARTERY, MAXILLARY
ARTERY, VIA THE MYLOHOID BRANCH OF INFERIOR ALVEOLAR ARTERY,
SUBMENTAL BRANCH OF FACIAL ARTERY
• Nerve supply: MYLOHYOID BRANCH OF INFERIOR ALVEOLAR NERVE

43. STYLOHYOID:
ORIGIN : posterior surface of styloid process
INSERTION : at the junction between hyoid bone and cornua
BLOOD SUPPLY : facial artery, posterior auricular and occipital artery.
NERVE SUPPLY: STYLOHYOID branch of facial nerve
DIGASTRIC :
ORIGIN: mastoid notch of temporal bone
INSERTION : DIGASTRIC fossa on the base of the mandible, 2 tendons meet in an intermediate
tendon which perforates the styloid & continues the fibrous sling.
BLOOD SUPPLY : POSTERIOR BELLY - posterior auricular & occipital arteries, ANTERIOR
BELLY – submental branch of facial artery
NERVE SUPPLY: MYLOHOID branch of inferior alveolar nerve, and the posterior belly is
supplied by facial nerve.

45. Depressors of LARYNX

46. Posterior
Cricoarytenoid
• Origin: Posterior surface of
lamina of cricoid cartilage
• Insertion: Muscular process of
arytenoid cartilage
• Nerve supply: Recurrent
Laryngeal Nerve (RLN)
• Abduct Vocal fold

48. Lateral
cricoarytenoid
• Origin: Arch of Cricoid Cartilage
• • Insertion: Muscular process of
arytenoid cartilage
• • Nerve supply :Recurrent
Laryngeal Nerve (RLN)
• • Adduct Vocal Fold

49. Thyroarytenoid
• Origin: Back of Thyroid
prominence and cricothyroid
ligament
• Insertion: Vocal process of
arytenoid cartilage and
anterolateral surface of Arytenoid
• Nerve supply: Recurrent
Laryngeal Nerve (RLN)
• Adducts and Relaxes vocal fold

50. Cricothyroid
• Origin: Anterolateral part of cricoid cartilage
• • Insertion: Inferior margin and Inferior horn of
Thyroid Cartilage
• • Nerve supply: External Branch of Superior
Laryngeal Nerve
• • Tenses Vocal Cord

51. Transverse
arytenoid
• Origin: Posterior surface of
muscular process and outer edge
of arytenoid
• Insertion: Same point on opposite
Arytenoid Cartilage
• Nerve supply: Recurrent
Laryngeal Nerve (RLN)
• Adductor of vocal fold

52. Oblique arytenoid
• Origin: Posterior aspect of Muscular
process (superficial to transverse
arytenoid)
• Insertion: Apex of other Arytenoid
• Nerve supply: Recurrent Laryngeal
Nerve (RLN)
• Adductor, Closes Laryngeal inlet

58. Key points
• Phonasthenia: Weakness of Voice due to fatigue of phonatory muscles
• • Elliptical space between cords- Weakness of Thyroarytenoid
• • Triangular gap near posterior commissure - weakness of Interarytenoid
• • Key hole appearance of glottis - both muscles are involved.

59. Anatomically larynx is divided into
SUPRAGLOTTIS
GLOTTIS
SUBGLOTTIS

60. CAVITY OF LARYNX
• Laryngeal inlet or aditus•
• Vestibular fold (False Vocal cord)•
• Glottis•
• Laryngeal Ventricle•
• Saccule•
• Vocal fold (True Vocal cord)•
• Subglottis

61. LARYNGEAL INLET OR ADITUS
• Aditus laryngis' is the aperture between the larynx and pharynx.
• This faces backwards and upwards.
• Anteriorly by the upper edge of the epiglottis
• Posteriorly - Transverse mucosal fold between the two arytenoids (posterior commissure)
• On each side by the aryepiglottic fold.
• The midline groove between the two CORNICULATE tubercles is termed the interaytenoid
notch.

64. VESTIBULAR FOLD( FALSE VOCAL
CORDS)
• Two thick folds of mucus membrane Enclosing vestibular ligament
• Anteriorly –Angle of thyroid cartilage
• Posteriorly- Fossa on anterolateral surface of Arytenoid
• Contains: vestibular ligament, few fibers of thyroarytenoid muscle and mucous glands.
• SPACE BETWEEN THE VESTIBULAR FOLD IS RIMA VESTIBULIS

65. GLOTTIC REGION
• Its an elongated fissure between vocal folds anteriorly and vocal processes and base of
arytenoid cartilage posteriorly
• Rima glottidis- narrowest part of laryngeal cavity , it’s the opening through which the
glottic part communicates with infraglottic part of larynx
• Anterior 2/3rd –Intermembranous part
• Posterior 1/3rd –Intercartilagenous part
• GLOTTIC CHINK: opening between the cords is called the GLOTTIC chink. In cadevric
position it is :14 mm. In full abduction it is about : 19 mm. During whispers it is :
paramedian

66. • Tumour restricted to Cords are detected earlier- present as Voice changes.
• Early Presentations and no local lymphatic spread – Good prognosiS
• Tumor of Subglottic present late ,spread to deep cervical lymphatic , it needs to grow large
to be visible beyond Vocal cord . Laryngoscopy is required

67. LARYNGEAL VENTRICLE/
VENTRICLE OF MORGAGNI
• On each side of the larynx, a slit between the
vestibular and vocal cords opens into a fusiform
recess called the laryngeal ventricle .
• The ventricle extends upwards into the laryngeal
wall lateral to the vestibular fold

69. SACCULE/ APPENDIX OF
VENTRICLE
• A pouch , ascends forwards from anterior part of ventricle, between the vestibular fold and
thyroid cartilage, and occasionally reaches the upper border of the cartilage.
• It is conical, and curves slightly forwards
• Mucous glands- 60-70, sited in the submucosa, open ontoits luminal surface.
• The ventriculosaccular fold.

70. LARYNGOCELE
• It is an abnormally large laryngeal saccule containing air or mucus
• Types- 1)Internal, 2)External, 3)Combined
• Internal-expand into the paraglottic space and extend superiorly to expand the aryepiglottic
fold and reach the vallecula
• External/combined- Expand through the thyrohyoid membrane at the point of entry of the
internal laryngeal neurovascular bundle- present as a lump in the neck overlying the
thyrohyoid membrane. Expands on raised Expiratory pressure
• If infected- Laryngopyocoele

71. VOCAL FOLD( TRUE VOCAL FOLD)
• The free thickened upper edge of the Cricovocal membrane forms the vocal ligaments .
• Middle of the angle of thyroid cartilage to the vocal processes of the arytenoids.
• The vocal cords form the anterolateral edges of the Rima Glottidis
• ANTERIOR 2/3 : MEMBRANOUS
• POSTERIOR 1/3 : CARTILAGENEOUS
• The mucosa overlying the vocal ligament is thin and lies directly on the vocal ligament, so
the vocal cord appears pearly white in vivo.
• The site where the vocal cords meet anteriorly is known as the anterior commissure.

72. Superficial layer- Stratified non Keratinizing squamous epithelium
Lamina propria – has three layers :
Superficial/Reinke’s space
The intermediate layer
Deep layer
Intermediate and deep layers forms the vocal ligament.
Vocalis- lateral and deep
BROYLE’S LIGAMENT : fibers of vocal ligament pass through the thyroid cartilage to
blend with the overlying perichondrium, forming BROYLE’S LIGAMENT
CONTENT: blood vessels and lymphatics.
Therefore it’s a potential route for the escape of malignant tumours from larynx

73. Cut section of vocal cord

74. • Reinke's oedema• Any tissue swelling
above the vocal cord exaggerates the
potential space deep to the mucosa
(Reinke's space), causing accumulation
of extracellular fluid and flabby swelling
of the vocal cords (Reinke's oedema).
• Smoking and vocal abuse may initiate
such changes.
• Vocal Nodule• At the junction of the
anterior third and the posterior two-
thirds of the vocal ligament
• Excessive trauma at this point,
haemorrhage or bruising, and subsequent
subepithelial scarring ('singer's nodes' or
'clergyman's nodes').

76. Different
positions of
VOCAL CORD

77. SUBGLOTTIS (LOWER PART)
• The lower part of the laryngeal cavity, extends from the vocal cords to the lower border of
the cricoid.
• In transverse section it is elliptical above , wider and circular below and is continuous with
the trachea.
• Its walls are lined by respiratory mucosa
• Subglottic region consists of mobile upper half and fixed lower half
• Upper portion is formed by the mucosa over conus elaticus
• During phonation upper half presumes the shape of “Gothicarch”
• Junction between the upper half and the lower half is 1cm below the vocal fold, coinciding
with cricothyroid membrane

78. JOINTS: 1. CRICOTHYROID JOINT
• Between the inferior cornua of the thyroid cartilage and the cricoid cartilage - synovial.
• Each is enveloped by a capsular ligament strengthened posteriorly by fibrous bands .
• Capsule and ligaments are rich in elastin fibres.
• The cricoid rotates on the inferior cornua around a transverse axis and to a limited extent, it
also glides in different directions on the thyroid cornua.

81. JOINT: 2. CRICOARYTENOID
• Synovial joints- between the upper border of the lamina of the cricoid cartilage and the
bases of the arytenoids.
• Each joint is enclosed by a capsular ligament and strengthened by a ligament that, although
called the posterior cricoarytenoid ligament, is medial in position.
• The posterior cricoarytenoid ligaments limit forward movements of the arytenoid cartilages
on the cricoid cartilage.

82. MUCOUS MEMBRANE OF THE LARYNX
• Closely attached over posterior surface of epiglottis, the corniculate, cunieform cartilages
and over vocal ligament.
• Elsewhere loosely attached, so liable to become swollen
• Lined by pseudostratified columnar epithelium EXCEPT at : 1) UPPER1/2 OF
POSTERIOR SURFACE OF EPIGLOTTIS. 2)UPPER PART OF ARYEPIGLOTTIC
FOLD 3) POSTERIOR COMMISURE 4) VOCAL FOLDS
• Most of the mucosa in supraglottic area covers the epiglottis
• Epithelium of vocal cords is prone to desiccation if the mucus glands of the saccule does
not function

83. SPACES
WITHIN
LARYNX

84. PRE EPIGLOTTICS SPACE
• Wedge shaped fat filled space with point of wedge inferiorly
• Anterior- Thyrohyoid ligament & Hyoid bone
• Posteriorly- Epiglottis
• Superiorly- Hyoepiglottic ligament
• Inferiorly- Thyroepiglottic
• Tumor may spread into this area through small perforations in the epiglottis or directly
through the hyo-epiglottic ligament. Dehiscence in thyrohyoid membrane for superior
laryngeal neurovascular bundle allows extension of tumor from pre- epiglottic space into
the neck.
• Can be invaded by carcinoma of supraglottic larynx and base of tongue

86. PARAGLOTTIC SPACE
• Antero-Laterally- Thyroid cartilage and cricothyroid membrane
• Medially- Conus elasticus and quadrangular membrane
• Posteriorly- Pyriform fossa mucosa
• The submucosa of the ventricle is continuous with the paraglottic space
• Potential space and together with pre-epiglottic space forms horse shoe shaped, fatty space
around laryngeal structures.

87. • Thus tumors involving the ventricle invade the paraglottic space and spread transglottically
• Vocal cord tumors which extend deep into the thyroarytenoid muscle invade paraglottic
resulting in subglottic and extralaryngeal spread.
• Proximity of pyriform sinus with posterior paraepiglottic space leads to spread of pyriform
fossa tumor into endolarynx

88. Nerve supply of LARYNX
• VAGUS NERVE:
• 1)Superior laryngeal nerve-
• External Branch
• Internal Branch
• 2)Recurrent laryngeal nerve

89. SUPERIOR LARYNGEAL NERVE
• Arises from the inferior ganglion of the Vagus and receives branch from superior cervical
sympathetic ganglion
• At level of greater horn of the hyoid divides into External & Internal branches
• Small external branch supplies CRICOTHYROID MUSCLE
• Large INTERNAL branch – pierces THYROHYOID MEMBRANE and divided into
UPPER & LOWER branches and pierces INFERIOR CONSTRICTOR and unites with
ASCENDING BRANCH OF RLN – AKA GALEN’S ANASTOMOSIS OR LOOP. It’s
purely sensory.
• Sensory supply to mucosa of larynx above vocal cord.

92. RECURENT LARYNGEAL NERVE
• Right – Loops around right subclavian artery
• Left – Loops around the aortic arch & ligamentum arteriosum
• Ascends in the tracheo-esophageal groove
• Enters the larynx behind cricotracheal joint
• Divides into motor & sensory branch
• Motor – all intrinsic muscles of larynx exceptcricothyroid
• Sensory – below the level of vocal folds

93. • Mediastinal, Oesophageal and lung tumor, aneurysm of aortic arch , may present as Voice
changes, more common on left side recurrent laryngeal nerve injury.
• Left vocal cord palsy twice more common than right
• NON RECUURENT RLN : associated with anomalous retroesophageal right subclavian
artery.

96. Recurrent laryngeal nerve injury
• Recurrent laryngeal nerve injury occurs during thyroidectomy, benign or malignant
enlargement of Thyroid gland, enlarged lymph nodes or cervical trauma.
• Unilateral Recurrent laryngeal nerve injury- Hoarseness, which resolves in 50%, either by
return of function or by compensatory mechanism
• .Bilateral Recurrent laryngeal nerve injury- complete loss of vocal power and marked
inspiratory stridor-requiring tracheostomy

97. Blood supply of
larynx
• Superior Laryngeal Artery branch
of Superior Thyroid Artery
(branch of External carotid
Artery).
• Inferior Laryngeal artery branch
of Inferior Thyroid Artery
(branch of Thyrocervical trunk of
1st part of Subclavian Artery).
• CRICOTHYROID artery –
branch of superior thyroid artery

98. Venous drainage
• Superior laryngeal vein - to superior
thyroid vein or facial vein – to internal
jugular vein
• Inferior thyroid vein – to inferior
thyroid vein – to brachiocephalic vein

99. Lymphatic
drainage
• Supraglottis-superior laryngeal
vessels-level II and III
• Anterior glottis and subglottis –
cricothyroid ligament-anteriorly
to level VI and laterally to Level
IV
• Posterior Glottis and Subglottis-
cricotracheal membrane to
paratracheal nodes in Level VI
and laterally to level IV

100. Paediatric larynx
• Funnel shaped, Subglottis is the narrowest part .
• It has a bearing in selecting Pediatricendotracheal tube.
• Cartilages are softer and collapse more easily on forced inspiration.Starts high up (infants
opposite C3-C4 at rest and reaches C1 or C2 during swallowing) under tongue , with age
assumes an increasingly lower position in the neck. Allows breathing during suckling
• Thyroid Cartilage is flat ,and overlaps cricoid cartilage and in turn is overlapped by hyoid
bone.
• Cricothyroid and Thyrohyoid spaces are narrow and not easily discernable as landmark
while doing Tracheostomy
• .Submucosal tissue comparatively loose .Easily undergo oedematous change with trauma or
inflammation leading to obstruction.

101. • Subglottis narrowest part- has complete cartilaginous ring
• Infant larynx shows two growth spurts :In first 3yrs of life larynx grows in width and length
• Second spurt during adolescence when thyroid angle develops, length of Vocal cords then
increases leading to voice change associated with puberty

102. Thank you