Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Human Anatomy ppt lectures Topic 25 Ent Larynx Notes. - anatomy ppt free download human anatomy ppt lectures, medicine notes ppt, anatomy handwritten notes pdf, mbbs 1st year anatomy notes pdf download, best anatomy notes pdf, human anatomy notes pdf, anatomy easy notes pdf, anatomy notes online, anatomy short notes, Anatomy ppt, Powerpoint Presentations and lecture notes.
STRIDOR
Harsh, high-pitched musical
sound
Produced by turbulence of airflow
through a partial obstruction in
the airway passage
ANATOMY OF LARYNX
Situated in midline of neck from the level
of C-3 to C-6 vertebrae lying in front of
laryngopharynx.
LARYNX
? Musculocartilagenous structure,
? Lined with mucous membrane
? Connected to pharynx and superior part of
trachea
? Acts as essential sphincter guarding entrance
into trachea
? Secondarily function as organ of voice
? Formed of nine cartilages connected by ligaments
and muscles
Topography of the extrinsic musculature of the
larynx
ADAM'S APPLE
At puberty male larynx increases in size
rapidly, and the thyroid cartilage projects
to form the Adam's apple.
CACARTILARTILAGEGESS OFOF LA
RYR
NXN
CAVITY OF LARYNX
EXTENT- from laryngeal inlet above to
lower border of cricoid cartilage.
Inlet of larynx communicates with
laryngopharynx.
CAVITY OF LARYNX
Divided into three parts by 2 folds of
mucus membrane: False cords and True
vocal cords
Parts are Vestibule, ventricle and
subglottic space
Glottis is the opening between vocal
folds
MUSCLES OF LARYNX- INTRINSIC
HISTOLOGY OF LARYNX
Mucous membrane lines the entire larynx.
Stratified squamous epithelium lines true
vocal cords and upper parts of vestibule.
Pseudostratified Columnar ciliated
epithelium lines rest of the cavity.
Mucous glands preset in all parts except
on free edges of vocal cords
LYMPHATIC DRAINAGE
SUPRAGLOTTIS-pre-epiglottic and upper
deep cervical nodes.
GLOTTIS-Lymphatics are practically
absent
SUBGLOTTIS-prelaryngeal and
pretracheal nodes also lower deep
cervical nodes
LARYNX OF AN INFANT DIFFERENT FROM ADULT
Infant's larynx is positioned high in the neck opposite C3 or
C4 (vocal cord level ) at rest and reaches C1 or C2 during
swal owing.
This high position al ows the epiglottis to meet soft palate
and make a nasopharyngeal channel for nasal breathing
during suckling.
The milk feed passes separately over the dorsum of
tongue and the side of epiglottis, thus al owing breathing
and feeding to go on simultaneously.
LARYNX OF AN INFANT
LARYNX OF AN INFANT DIFFERENT FROM ADULT
Laryngeal cartilages are soft and col apse easily.
Epiglottis is omega-shaped and arytenoids
relatively large covering significant portion of
the posterior glottis .
LARYNX OF AN INFANT DIFFERENT FROM ADULT
Thyroid cartilage in an infant is flat.
It also overlaps the cricoid cartilage and is in turn
overlapped by the hyoid bone.
Thus cricothyroid and thyrohyoid spaces are narrow and not
easily discernible as landmarks when performing
tracheostomy.
LARYNX OF AN INFANT DIFFERENT FROM ADULT
Infant's larynx is smal and conical. The diameter of cricoid
cartilage is smal er than the size of glottis, making
subglottis the narrowest part.
It has a bearing in the selection of paediatric endotracheal
tube.
In adults, subglottic-glottic dimensions are approximately
same and larynx is cylindrical.
LARYNX OF AN INFANT DIFFERENT FROM ADULT
Submucosal tissues of infant's larynx are comparatively
loose and easily undergo oedematous change
with trauma or inflammation leading to obstruction.
Infant's larynx shows two spurts in growth. In the first
three years of life larynx grows in width and length, and
thus obviates the need for any airway surgery in certain
congenital anomalies.
LARYNX OF AN INFANT DIFFERENT FROM ADULT
The second spurt in growth occurs
during adolescence when the thyroid angle
develops. The length of vocal cords then
increases leading to voice
changes associated with puberty.
With growth of the neck, larynx gradual y
descends to adult
position opposite Cs (vocal cord level).
LARYNX OF AN INFANT DIFFERENT FROM ADULT
In childhood, vocal cord is 6 mm in
females and 8 mm in males.
It increases to 15-19 mm in adult females
and
17-23 in adult male.
Adult male voices are usual y lower-pitched
and have larger folds.
INFANT AIRWAY
The subglottic diameter measures
approximately 4.5
A diameter of less then 3.5 mm suggests a
marginal subglottic airway and is consistent
with subglottic stenosis
INFANT AIRWAY
?Circumferential mucosal edema of 1 mm within the larynx
of an infant causes a glottis to narrow by over 60% to
75%.
LOCATION OF OBSTRUCTION
Stridor can be localized to discrete areas of the
airway according to the nature of the sound
in relationship to the phase of breathing
LOCATION OF OBSTRUCTION
These discrete regions can be divided into three
zones
Supraglottic and supralaryngeal zone which includes the
pharynx
Extrathoracic tracheal zone including both glottis
subglottis and cervical trachea
Intrathoracic tracheal
zone which includes
primary and secondary bronchi
LOCATION OF OBSTRUCTION
Supraglottis or Pharynx - Inspiratory and high- pitched-
Glottis and Subglottis (extrathoracic tracheal zone)-
Biphasic of intermediate pitch
Intrathoracic tracheal/bronchial zone- Expiratory often
confused with wheezing
ANATOMY OF TRACHEA
Tube made up of cartilage and membrane
and measures approx 10-11cm in adult
Extends from C-6 to T-5
There are 16-20 incomplete cartilaginous
rings. In neck 6-7 rings are present.
BLOOD SUPPLY
The inferior thyroid vessels and their
tracheoesophageal branches provide blood
supply to the proximal trachea while the
bronchial arteries vascularize the distal
trachea, carina, and main bronchi
The trachea is also supplied by smal branches
originating from the subclavian artery, internal
mammary artery, and innominate artery.
VENOUS AND LYMPHATIC DRAINAGE
Venous drainage is through the azygos and
hemi azygos systems while lymphatic
drainage is through the low and high
paratracheal nodal chains eventual y
reaching the deep cervical nodes.
NERVE SUPPLY
Vagus, recurrent laryngeal nerve and
sympathetic trunk
LYMPHATICS
Pretracheal and paratracheal lymph nodes
This post was last modified on 05 April 2022