Download MBBS Anatomy PPT 25 Ent Larynx Notes

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