106 Malignant tumors of larynx Flashcards
Supraglottic larynx derived from:
Glottis and subtlottis derived from:
PRIMORDIUM
From which branchial arches?
Supraglottic larynx derived from:
BUCCOPHARYNGEAL PRIMORDIUM
Third and Fourth
Blood supply
Supraglottis:
Glottis, subglottis:
Blood supply
Supraglottis: superior laryngeal arteries
Glottis, subglottis: inferior laryngeal arteries
Lymphatic drainage:
Supraglottis:
Glottis, subglottis:
Lymphatic drainage:
Supraglottis: II, III
Glottis, subglottis: VI -> IV
The
supraglottis is supplied by the superior laryngeal arteries, and
its lymphatic drainage follows these vessels to the carotid sheath
to drain into deep cervical chain nodes in levels II and III. The
glottis and subglottis are supplied by the inferior laryngeal
arteries, and similarly, lymphatic drainage from these two
regions follows these arteries to drain into prelaryngeal and
pretracheal nodes (level VI), before it reaches the deep cervical
chain nodes in level IV.3
Lymphatic drainage: unilateral vs bilateral
Glottis
Supraglottis
Glottis: Unilateral
Supraglottis: Bilateral
The glottis is formed by paired structures that fuse in the
midline. The lymphatics drain unilaterally, and the vocal folds
have sparse lymphatics; therefore glottic cancers must invade
deeply before they gain access to lymphatic channels. These
factors explain the lower incidence of lymphatic metastasis in
glottic SCC and the propensity for unilateral metastases.
Because the supraglottis is formed without a midline union, its
lymphatics drain bilaterally. The increased likelihood of bilat
eral
lymphatic metastases from supraglottic carcinoma is
ascribed to this embryologic factor.
Laryngeal framework:
Unpaired:
1.
2.
3.
Paired:
1.
Unpaired:
- Thyroid cartilage
- Epiglottis
- Cricoid
Paired:
1. Arytenoid
Boundaries of the larynx:
Superior: Anterosuperior: Anterior: - Supraglottis - Glottis - Subglottis
Inferior:
Posterior and Lateral:
Boundaries of the larynx:
Superior: tip and lateral margin of epiottis, , superior edge of aryepiglottic folds
Anterosuperior:lingual surface of the suprahyoid epiglottis, hyoepoglottic ligament
Anterior:
- Supraglottis: thyroid cartilage, thyrohyoid membrane
- Glottis: thyroid cartilage
- Subglottis: cricoid cartilage, cricothyroid membrane
Inferior: horizontal line passing across inferior edge of cricoid
Posterior and Lateral: laryngeal surface of aryepiglottic folds, arytenoids, interarytenoid space, posterior surface of the subglottic space
Forma superior boundary of preepiglottic space
Hyoepiglottic ligament
Glottis and subglottis forebearers:
from which branchial arch?
tracheobronchial primordium
sixth branchial arch
Parts of supraglottis:
suprahyoid epiglottis infrahyoid epiglottis laryngeal surface of aryepiglottic folds arytenoids false vocal cords
Boundary between supra and infrahyoid epiglottis
hyoid bone
Inferior limit of supraglottis:
horizontal plane through the lateral margin of the VENTRICLE at its junction with the SUPERIORsurface of the TRUE VOCAL CORD
Components of the glottis:
True vocal cords
Anterior commissure
Posterior commissure
Inferior boundary of the glottis:
horizontal plane 1 cm inferior to the inferior limit of the supraglottis
(The inferior limit of the supraglottis is defined as the lateral margin of the ventricle at its junction with the superior surface of the vocal cord)
EPITHELIUM.
Supraglottis:
Glottis:
Subglottis:
Supraglottis: pseudostratified columnar (except at edges of the ARYEPIGLOTTIC FOLDS AND LATERAL BORDERS of the EPIGLOTTIS - Stratified Squamous)
Vocal cords: Stratified squamous
Subglottis: pseudostratified columnar
In summary:
Supra and subglottis: pseudostratified columnar
Forms the superior bordered of the conus elasticus:
and this structure is made up of ____ and ___
vocal ligament - made up of intermediate and deep layers of the lamina propria