The larynx develops from two primordia - the supraglottis develops from the third and fourth branchial arches, while the glottis and subglottis develop from the sixth branchial arch. This gives the larynx a dual blood supply. The supraglottis includes the epiglottis, aryepiglottic folds, and arytenoids. The glottis is made up of the vocal cords. The subsite below the glottis is also called the subglottis. The larynx contains membranes like the cricovocal membrane and quadrangular membrane. It also contains spaces like the ventricle and pre-epiglottic space

1. larynx
Dr Somnath Saha

2. EMBRYOLOGY
 The supraglottic larynx
is derived from the
buccopharyngeal
primordium, which
develops from the third
and fourth branchial
arches.

3. EMBRYOLOGY
 The glottis and
subglottis are derived
from the
tracheobronchial
primordium from the
sixth branchial arch and
are formed by the union
of lateral furrows that
develop on each side of
the tracheobronchial
primordium. Therefore
the larynx has a dual
blood supply and
lymphatic drainage.

4. SUBSITES Site Subsite
Supraglottis
Suprahyoid epiglottis
Infrahyoid epiglottis
Aryepiglottic folds, right and left (laryngeal surfaces)
Arytenoids, right and left
Ventricular bands, right and left
Glottis
True vocal
cords, right and
left (including
the anterior
and posterior
commissures)
Subglottis
No separate
subsites
defined

5.  The supraglottis is composed of
the suprahyoid and infrahyoid
epiglottis (both the lingual and
the laryngeal surfaces),
aryepiglottic folds (laryngeal
surfaces only), arytenoids, and
ventricular bands (false vocal
cords).
 The boundary between the
suprahyoid and infrahyoid
epiglottis is a horizontal plane
passing through the hyoid
bone.
 The inferior limit of the
supraglottis is a horizontal
plane through the lateral margin
of the ventricle at its junction
with the superior surface of the
true vocal cord.

6.  The glottis is composed of
the true vocal cords (both
the superior and inferior
surfaces) and includes the
anterior and posterior
commissures. The inferior
boundary of the glottis is a
horizontal plane 1 cm
inferior to the inferior limit of
the supraglottis (defined as
the lateral margin of the
ventricle at its junction with
the superior surface of the
vocal cord). The subglottis
extends from the inferior
limit of the glottis to the
inferior edge of the cricoid
cartilage

7. LARYNGEAL MEMBRANES
 Cricovocal membrane:
triangular fibroelastic
memb—Upper border is
free—Stretches between
middle of thyroid angle
to the VP --forms –
VOCAL LIG. Lower
border attached to arch
of cricoid cartilage—Ant
end moves upward &
medially to meet its
fellow from opposite side
CONUS ELASTICUS –
resist extra laryn spread
of glottic &subglottic ca

8. LARYNGEAL MEMBRANES
 QUADRANGULAR
MEMBRANE
 Deep to the mucosa
of AE fold
 Not well defined
 Stretches between
epiglottis & arytenoid
cartilages.
 Lowr border forms
Vestibular lig –lies in
the false cord.

9. CAVITY OF THE LARYNX
 Ventricle/Sinus of
larynx
 Deep illiptical space
betw Vestibular & vocal
folds.
 Extend a short distance
above & lateral to
vestibular folds
 Saccule –a mucous
diverticulum from ant
part of ventricular cavity
extend upwords betw
VF & Thyroid lamina---
Laryngocele
 Absence of QM &CVM.

10. COMPARTMENTS OF LARYNX -contd
 Pre Epiglottic Space Of
Boyer.
 ANT –Thyrohyoid membr &
Thyroid cartilage above the
thyroepiglottic ligament.
 Superiorly hyoepiglottic lig
&mucosa of vallecula
 Posteriorly infrahyoid
epiglottis & thyroepiglottic
lig.
 laterally, the PES is open
and continuous with each
of the two PGSs

11. The PES contains fat and areolar
tissue[7] and is frequently invaded
by tumors because the cartilage of
the epiglottis has multiple small
fenestrations through which
cancers arising from the infrahyoid
epiglottis may pass. Superiorly, the
hyoepiglottic ligament provides a
barrier to spread of tumor to the
tongue base (Fig. 107-3). The
lymphatics of the PES drain
through the thyrohyoid membrane,
spreading to lymph nodes on both
sides of the neck, primarily in
zones II and III (Fig. 107-4).[5]
Supraglottic tumors with PES
involvement are staged as T3

15. Transglottic tumour
 a tumor that crosses the ventricle in a vertical
direction
 Tumors can become transglottic in four ways: by
crossing the ventricle directly; by crossing at the
anterior commissure; by spreading through the
paraglottic space; and by spreading along the
arytenoid cartilage posterior to the ventricle