Produced by turbulence of airflow
through a partial obstruction in
--- Content provided by FirstRanker.com ---
the airway passage
ANATOMY OF LARYNX
--- Content provided by FirstRanker.com ---
Situated in midline of neck from the levelof C-3 to C-6 vertebrae lying in front of
laryngopharynx.
--- Content provided by FirstRanker.com ---
LARYNX
? Musculocartilagenous structure,
--- Content provided by FirstRanker.com ---
? Lined with mucous membrane? Connected to pharynx and superior part of
trachea
--- Content provided by FirstRanker.com ---
? Acts as essential sphincter guarding entrance
into trachea
--- Content provided by FirstRanker.com ---
? Secondarily function as organ of voice? Formed of nine cartilages connected by ligaments
and muscles
--- Content provided by FirstRanker.com ---
Topography of the extrinsic musculature of the
larynx
--- Content provided by FirstRanker.com ---
ADAM'S APPLE
At puberty male larynx increases in size
--- Content provided by FirstRanker.com ---
rapidly, and the thyroid cartilage projectsto form the Adam's apple.
--- Content provided by FirstRanker.com ---
CACARTILARTILAGEGESS OFOF LARYR
NXN
--- Content provided by FirstRanker.com ---
CAVITY OF LARYNX
EXTENT- from laryngeal inlet above to
--- Content provided by FirstRanker.com ---
lower border of cricoid cartilage.
Inlet of larynx communicates with
--- Content provided by FirstRanker.com ---
laryngopharynx.CAVITY OF LARYNX
Divided into three parts by 2 folds of
--- Content provided by FirstRanker.com ---
mucus membrane: False cords and True
vocal cords
--- Content provided by FirstRanker.com ---
Parts are Vestibule, ventricle andsubglottic space
Glottis is the opening between vocal
--- Content provided by FirstRanker.com ---
folds
MUSCLES OF LARYNX- INTRINSIC
--- Content provided by FirstRanker.com ---
HISTOLOGY OF LARYNX
Mucous membrane lines the entire larynx.
--- Content provided by FirstRanker.com ---
Stratified squamous epithelium lines true
vocal cords and upper parts of vestibule.
--- Content provided by FirstRanker.com ---
Pseudostratified Columnar ciliatedepithelium lines rest of the cavity.
Mucous glands preset in all parts except
--- Content provided by FirstRanker.com ---
on free edges of vocal cords
LYMPHATIC DRAINAGE
--- Content provided by FirstRanker.com ---
SUPRAGLOTTIS-pre-epiglottic and upperdeep cervical nodes.
GLOTTIS-Lymphatics are practically
--- Content provided by FirstRanker.com ---
absent
SUBGLOTTIS-prelaryngeal and
--- Content provided by FirstRanker.com ---
pretracheal nodes also lower deepcervical nodes
LARYNX OF AN INFANT DIFFERENT FROM ADULT
--- Content provided by FirstRanker.com ---
Infant's larynx is positioned high in the neck opposite C3 or
C4 (vocal cord level ) at rest and reaches C1 or C2 during
--- Content provided by FirstRanker.com ---
swal owing.This high position al ows the epiglottis to meet soft palate
and make a nasopharyngeal channel for nasal breathing
--- Content provided by FirstRanker.com ---
during suckling.The milk feed passes separately over the dorsum of
tongue and the side of epiglottis, thus al owing breathing
--- Content provided by FirstRanker.com ---
and feeding to go on simultaneously.LARYNX OF AN INFANT
LARYNX OF AN INFANT DIFFERENT FROM ADULT
--- Content provided by FirstRanker.com ---
Laryngeal cartilages are soft and col apse easily.Epiglottis is omega-shaped and arytenoids
relatively large covering significant portion of
--- Content provided by FirstRanker.com ---
the posterior glottis .
LARYNX OF AN INFANT DIFFERENT FROM ADULT
--- Content provided by FirstRanker.com ---
Thyroid cartilage in an infant is flat.It also overlaps the cricoid cartilage and is in turn
overlapped by the hyoid bone.
--- Content provided by FirstRanker.com ---
Thus cricothyroid and thyrohyoid spaces are narrow and not
easily discernible as landmarks when performing
--- Content provided by FirstRanker.com ---
tracheostomy.LARYNX OF AN INFANT DIFFERENT FROM ADULT
Infant's larynx is smal and conical. The diameter of cricoid
--- Content provided by FirstRanker.com ---
cartilage is smal er than the size of glottis, making
subglottis the narrowest part.
--- Content provided by FirstRanker.com ---
It has a bearing in the selection of paediatric endotrachealtube.
In adults, subglottic-glottic dimensions are approximately
--- Content provided by FirstRanker.com ---
same and larynx is cylindrical.
LARYNX OF AN INFANT DIFFERENT FROM ADULT
--- Content provided by FirstRanker.com ---
Submucosal tissues of infant's larynx are comparativelyloose and easily undergo oedematous change
with trauma or inflammation leading to obstruction.
Infant's larynx shows two spurts in growth. In the first
--- Content provided by FirstRanker.com ---
three years of life larynx grows in width and length, andthus obviates the need for any airway surgery in certain
congenital anomalies.
LARYNX OF AN INFANT DIFFERENT FROM ADULT
--- Content provided by FirstRanker.com ---
The second spurt in growth occursduring adolescence when the thyroid angle
develops. The length of vocal cords then
--- Content provided by FirstRanker.com ---
increases leading to voicechanges associated with puberty.
With growth of the neck, larynx gradual y
descends to adult
--- Content provided by FirstRanker.com ---
position opposite Cs (vocal cord level).LARYNX OF AN INFANT DIFFERENT FROM ADULT
In childhood, vocal cord is 6 mm in
--- Content provided by FirstRanker.com ---
females and 8 mm in males.
It increases to 15-19 mm in adult females
and
--- Content provided by FirstRanker.com ---
17-23 in adult male.Adult male voices are usual y lower-pitched
and have larger folds.
--- Content provided by FirstRanker.com ---
INFANT AIRWAYThe subglottic diameter measures
approximately 4.5
--- Content provided by FirstRanker.com ---
A diameter of less then 3.5 mm suggests a
marginal subglottic airway and is consistent
--- Content provided by FirstRanker.com ---
with subglottic stenosisINFANT AIRWAY
?Circumferential mucosal edema of 1 mm within the larynx
--- Content provided by FirstRanker.com ---
of an infant causes a glottis to narrow by over 60% to
75%.
--- Content provided by FirstRanker.com ---
LOCATION OF OBSTRUCTION
Stridor can be localized to discrete areas of the
--- Content provided by FirstRanker.com ---
airway according to the nature of the soundin relationship to the phase of breathing
LOCATION OF OBSTRUCTION
--- Content provided by FirstRanker.com ---
These discrete regions can be divided into three
zones
--- Content provided by FirstRanker.com ---
Supraglottic and supralaryngeal zone which includes thepharynx
Extrathoracic tracheal zone including both glottis
--- Content provided by FirstRanker.com ---
subglottis and cervical trachea
Intrathoracic tracheal
--- Content provided by FirstRanker.com ---
zone which includesprimary and secondary bronchi
LOCATION OF OBSTRUCTION
--- Content provided by FirstRanker.com ---
Supraglottis or Pharynx - Inspiratory and high- pitched-
Glottis and Subglottis (extrathoracic tracheal zone)-
--- Content provided by FirstRanker.com ---
Biphasic of intermediate pitchIntrathoracic tracheal/bronchial zone- Expiratory often
confused with wheezing
--- Content provided by FirstRanker.com ---
ANATOMY OF TRACHEA
Tube made up of cartilage and membrane
--- Content provided by FirstRanker.com ---
and measures approx 10-11cm in adult
Extends from C-6 to T-5
There are 16-20 incomplete cartilaginous
--- Content provided by FirstRanker.com ---
rings. In neck 6-7 rings are present.
BLOOD SUPPLY
--- Content provided by FirstRanker.com ---
The inferior thyroid vessels and their
tracheoesophageal branches provide blood
--- Content provided by FirstRanker.com ---
supply to the proximal trachea while thebronchial arteries vascularize the distal
trachea, carina, and main bronchi
--- Content provided by FirstRanker.com ---
The trachea is also supplied by smal branches
originating from the subclavian artery, internal
--- Content provided by FirstRanker.com ---
mammary artery, and innominate artery.VENOUS AND LYMPHATIC DRAINAGE
Venous drainage is through the azygos and
--- Content provided by FirstRanker.com ---
hemi azygos systems while lymphatic
drainage is through the low and high
--- Content provided by FirstRanker.com ---
paratracheal nodal chains eventual yreaching the deep cervical nodes.
--- Content provided by FirstRanker.com ---
NERVE SUPPLYVagus, recurrent laryngeal nerve and
sympathetic trunk
--- Content provided by FirstRanker.com ---
LYMPHATICS
Pretracheal and paratracheal lymph nodes
--- Content provided by FirstRanker.com ---