2. INTRODUCTION
Anterior to the inferior portion of the pharynx and
superior to the trachea.
Protects the lower airway by closing abruptly upon
mechanical stimulation,
Production of sound (phonation),
Coughing,
Valsalva maneuver
Control of ventilation
Sensory organ
3. ZONES
1. Supraglottis – laryngeal inlet
to ventricle.
2. Glottis- true vocal volds.
3. Subglottis – true vocal fold to
lower border of cricoid.
4. EMBRYOLOGICAL DEVELOPMENT
4th week of life- laryngeal
development starts.
Tracheobronchial groove is a
outgrowth of primitive gut.
Supraglottis arises from
buccopharyngeal bud (4th
pharyngeal arch),Glottis and
sub-glottis from 6th arch.
8. RELATIONS OF LARYNX
Opposite 3rd to 6th vertebrae.
Anterior – skin, infrahyoid
muscles, pyramidal lobe of
thyroid.
Lateral – great vessels of neck,
thyroid.
Posterior – laryngopharynx, pre
vertebral fascia and muscles.
9. PAEDIATRIC VS ADULT
Positioned higher – inferior margin of cricoid
reaching C4 vertebra.
Thyroid cartilage is positioned almost inside the
arch of hyoid.
Simultaneous breathing and suckling.
Birth size is almost 1/3rd of adult size,
Subglottis is 5-7 mm in diameter.
Epiglottis is more tubular and omega shaped.
Shows acceleratated pattern of growth in the 1st
, 3 year .
13. THYROID CARTILAGE
Most prominent cartilage
Two laminae
Thyroid notch
Superior and inferior cornua
Vocal fold lies closer to the inferior
border of the thyroid cartilage
15. CRICOID CRTILAGE
Signet ring
Only cartilage to completely encircle the airway
Lumen of the larynx is fixed at this point
In infant larynx this part is narrowest
20. THYROARYTENOID
Allow larynx to produce pricise
changes in shape , position ,
tensioning .
Sphinteric action protects the
airway.
External belly is supplied by fast-
twitch nerve fibres- for coughing
and rapid protection of airway.
Vocalis is innervated by slow
twitch fibres – for accurate
movement of phonation.
23. CRICOTHYROID MUSCLE
The tensors of the vocal folds .
Laryngeal tilt / rocking – pivoting
the larynx – important for singers
while singing in high pitch .
24. EXTRINSIC MUSCLE OF LARYNX
Suprahyoid group- myelohyoid, digastric,
geniohyoid,
Stylohyoid.
Elevates the larynx.
Infrahyoid –sternohyoid, omohyoid,
thyrohyoid, sternothyroid.
Depress the larynx.
25. LIGAMENTS AND MEMBRANES
Thyrohyiod membrane-
Median and lateral thyrohyoid
ligaments
Pierced by neurovascular bundle.
Cricothyroid membrane-
Cricothyroid ligament
Cricothyrotomy
Reduces in MTD
26. CONT..
Quadrangular membrane – epiglottis to
arytenoid,
Aryepiglottic fold
False vocal cords
Medial wall of PFS.
Conus elasticus- cricovocal membrane –
thick fibroelastic support of glottis.
From superior border of cricoid to ant
commissure and vocal process
Forms vocal ligament.
30. SPACES IN THE LARYNX
Ventricle- space between true
and false vocal cords.
Paraglottic space- laterally by
perichondrium of thyroid
caetilage and cricothyroid
membrane.
Posterriorly by mucous
membrane of PFS.
Pyriform sinus- medially AE fold
, laterally thyroid cartilage and
thyrohyoid membrane.