anatomy of larynx, including the spaces associated with larynx the muscles and the paired unpaired cartilages, the attachment of the muscles and the associated functions . true and false vocal cords and the clinical pathology associated with larynx . the blood supply, nerve supply and the lymphatic drainage of the larynx

1. LARYNX
DR SANAYASEEN
ANATOMY DEPARTMENT

2. INTRODUCTION
 Is the organ of phonation also an air passage
 Situated in the anterior midline of neck
 Extend from root of tongue to trachea
 Adults : C3-C6
 Children : little higher
 Is made up of skeletal framework of cartilages, they are
moved by muscles
 The laryngeal cavity may be divided into 3 major regions:
the vestibule, the middle, and the infraglottic space. The
vestibule is the upper portion of the cavity, in between
the laryngeal inlet and the vestibular folds

4. CARTILAGES
PAIRED
CARTILAGES
UNPAIRED
CARTILAGES
1.Arytenoid
2.Corniculate
3.Cuneiform
1.Thyroid
2.Cricoid
3.Epiglottic

6. Thyroid Cartilage
 Shied shaped, open posteriorly, angulated
anteriorly
 Angulation more acute in males
 Its function is to shield larynx from injury
and provide an attachment to vocal cords

7. Cricoid Cartilage
 Signet ring shaped
 Stronger than thyroid
cartilage.
 Lamina – 2 to 3 cm
from above
downwards,
considerably broader
than anterior arch.

8.  Important from structural & functional point of
view
 Base for entire larynx
 Support to arytenoid
 Attachment to intrinsic muscles
 Only part of cartilagenous framework that
forms continuous 360 degree ring
 Once injured or strictured , difficult to resect
while preserving laryngeal function

9. Epiglottis
 Thin leaf shaped fibro-cartilage,
situated in midline
 Upper free end broad & rounded,
projects up behind base of
tongue.
 Narrow base called pitiole, are
pointed and attach to upper part
of between two lamina of thyroid
cartilage.
 This attachment forms lower limit
of pre-epiglottis space

10.  Half of epiglottis
projects above
hyoid
 This part has a
laryngeal and
lingual surfaces

11.  Infrahyoid portion has
no free anterior
surface
 Forms posterior wall
of Pre Epiglottic
Space
 Epiglottic cartilage
contains many pits
filled with mucous
glands
 Little barrier between
infrahyoid portion and
PES

12. ARYTENOIDS
 Paired cartilages, pyramidal
in shape
 Base articulated with cricoid
 PCA & LCA muscles attach
on muscular process
 Anterior angle elongated into
vocal process which
receives insertion of vocal
ligament

13. SUPRAGLOTTIS
 Consists of ventricles,
false cords, laryngeal
surface of epiglottis,
aryepiglottic folds and the
mucosal expanse.
 Posterior tapering shape
reduces area of mucosa in
posterior region
 So majority of SG tumors
are epiglottic

14. GLOTTIS
 Consists of true cords,
anterior commissure and
posterior commissure
 Narrow triangular space
between the true cords is
called rima glottis
 Anterior 2/3 is membranous
 Posterior third consists of
vocal processes of arytenoids
 Posterior 1/3 of cords and
covering mucosa are called
posterior commissure

15. SUB-GLOTTIS
 Begins about 5mm below free
margins of VC
 Consists of a mobile upper
and fixed lower part

16. Mucosa
 Mucosa of glottic and Supraglottic regions
is stratified squamous epithelium.
 Mucosa of ventricles and sub-glottic
regions is pseudo-stratified ciliated
epithelium
 Supra and sub glottic regions particularly
ventricles are rich in submucosal mucous
or minor salivary glands while glottis is not.

17. Pre-EPIGLOTTIC SPACE
 The pre-epiglottic space
(PES) is a triangular fat-
containing space between
the epiglottis and hyoid
bone.
 Bound sup by hyo-
epiglottic ligament, ant by
thyrohyoid memb. &
thyroid cartilage and
posteriorly by epiglottis

18. Boundaries
 superior: hyoepiglottic
ligament
 anterior: thyrohyoid
membrane, thyroid
cartilage
 inferior: thyroepiglottic
ligament
 posterior: epiglottis,
quadrangular membrane

19.  Filled with fat and
areolar tissue
 Continuous with
para-glottic space
 Cx of laryngeal
surface of epiglottis
readily spread to
PreEpiSpace

20. CLINICAL SIGNIFICANCE
 This area is rich in lymphatics which drain from the
supraglottic larynx to cervical nodes. The PES is at high
risk of involvement of oropharyngeal and supraglottic
laryngeal carcinomas.
 It is important in staging as invasion of the PES
automatically raises the TNM staging to T3 in
oropharyngeal and supraglottic laryngeal carcinomas.
 PES involvement necessitates more aggressive surgical
treatments with higher morbidity such as supraglottic or
total laryngectomy, in contrast to more conservative
treatment such as local resection or radiation therapy
which may be considered when the PES is not involved.

21. PARA-GLOTTIC SPACE
 The paraglottic space is a fat-containing space
located on either side of the larynx.
Boundaries and/or relations
 laterally: thyroid cartilage
 superomedially: pre-epiglottic space
 inferomedially: conus elasticus
 posteriorly: pyriform sinus
 The space surrounds the laryngeal ventricle.

23. Para-glottic space

24. CLINICAL SIGNIFICANCE
 squamous cell carcinoma of the larynx
 The paraglottic space offers a submucosal
pathway through which transglottic spread of
tumor occurs (crossing the ventricle to involve
both the false vocal cords in the
supraglottis and the true vocal cords in the
glottis)
 laryngocele

25. REINKE’S SPACE
 Is a submucosal potential
space of true vocal cord
bounded above an below
by the junctions of
squamous with
respiratory epithelium,
along most of the length
of truer Vocal cord.
 Mucosa over the vocal
ligament loosely attached
to ligaments
Reinke’s Space

26. BOUNDED
 Anteriorly: anterior commisure
 Posteriorly : tip of vocal process of arytenoid
REINKE’S EDEMA
 Is the edema of this space
 vocal cords (non-muscle part of the vocal cord,
sometimes called the vocal fold) are impacted by the
swelling, they cannot vibrate in the usual way. That
means the voice will sound different.
Reinke's edema symptoms
 A low, raspy voice.
 Shortness of breath

27. REINKE’S
EDEMA

28. Composition of the Larynx
 Composed of Muscle:
 Extrinsic Laryngeal Muscles
 Intrinsic Laryngeal Muscles

29. EXTRINSIC MUSCLES
TWO Groups of Extrinsic Muscles:
 Suprahyoids – Attach to points above the Hyoid
(Jaw, Skull and Tongue) when they contract they
raise or elevate the Larynx eg Swallowing
 Infrahyoids – Attach to points below the Hyoid
(one connects to the thyroid, however the others
connect to the sternum and the scapula) when
they contract they lower or depress the Larynx

30.  Namely
- Cricothyroid
- Posterior cricoarytenoid
- Lateral cricoarytenoid
- Transverse arytenoid
- Oblique arytenoid
- Thyroarytenoid
INTRINSIC MUSCLES

31. Intrinsic Muscles
 Adductors – vocal folds are together
 Abductors – vocal folds apart
 Tensors - Stiffen
 Relaxors - Relax

32. Adductors of LARYNX
 Lateral
Cricoarytenoids
 Interarytenoids
 Transverse
Arytenoids
 Oblique
Arytenoids

33. Adductors

34. Adductors of the Vocal Folds

35. Abductors of Larynx
 Posterior
Cricoarytenoids

37. CRICOTHYROID MUSCLE
This is the only instrinsic muscle lying on
the external aspect of larynx

38. MUSCLES ACTING ON LARYNX
MOVEMENT MUSCLES
Elevation of larynx Thyrohyoid, mylohyoid
Depression Sternothyroid. Sternohyoid
Opening inlet of larynx Throepiglotticus
Closing inlet Aryepiglotticus
Abdductor of vocal cords Posterior cricoarytenoid only
Adductor Lateral cricoarytenoid ,
transverse oblique
arytenoids
Tensor of vocal cord cricothyroid
Relaxor Thyroarytenoid

39. VOCAL FOLDS
 Muscle
 External Thyroarytenoids – inserts into the
muscular process on the Arytenoids and
the Thyroid notch (shorten and adduct)
 Internal Thyroarytenoids – inserts into the
vocal process on the Arytenoids and the
Thyroid Notch (shortens and stiffens), act
antagonistically to the Cricothyroids
 Membrane

40. ARTERIAL SUPPLY
 Up to the vocal folds:
Sup. Laryngeal A. from
Sup. Thyroid artery
 Superior laryngeal vein
drains into superior
thyroid vein.
 Below the vocal folds: Inf.
Laryngeal A. from Inf.
Thyroid artery
 Inferior laryngeal vein
drains into inferior thyroid
vein

41. NERVE SUPPLY:
Derived from the Vagus
 Motor: All muscles are supplied
by recurrent laryngeal nerve expt
for cricothyroid muscle which is
supplied by external laryngeal
nerve
 Sensory:
Up to vocal fold: internal laryngeal
nerve
Below vocal folds: recurrent
laryngeal nerve

42. LYMPHATIC DRAINAGE
 Above vocal cord: superior thyroid to antero
superior group of deep cervical lymphnodes
 Below vocal cords: posteroinferior group of deep
cevicle lymphnodes
 Few drains into prelaryngeal nodes

43. CLINICALS OF LARYNX

44.  Due to its long course, the recurrent laryngeal nerve is
susceptible to damage.
 In unilateral RLN palsy, one vocal cord is paralysed. The
other vocal cord tends to compensate, and speech is not
affected to a great degree, although the patient may
experience hoarseness of voice.
 In bilateral palsy, both vocal cords are paralysed in a position
between adduction and abduction. Breathing is impaired, and
phonation cannot occur.
 Damage to external laryngeal nerve causes some weakness
of phonation due to loss of tightening effect of cricothyroid on
the vocal cord

45.  Laryngitis: is infection of larynx , characterised by
hoarseness of voice
 Since larynx or epiglottis is the narrowest part of
repiratory passage foreign bodies are usualy lodge here
 SEMON’S LAW:
In progressive lession of recurrent laryngeal nerve posterior
cricoarytenoids are first to get paralysed and last to recover
as compare to adductors.

46. THANK YOU...