1. ANATOMY OF LARYNX
AND TRACHEA
DEPT OF
OTORHINOLARYNGOLOGY
P I M S

2. DEVELOPMENT OF LARYNX
 Larynx develops from the
tracheobroncheal groove which is ventral
midline respiratory diverticulum of the
foregut.
 Epiglottis and the Thyroid cartilage
develop from the fourth branchial arch.

3. SITUATION OF LARYNX
 Situated in midline of neck from the level
of C-3 to C-6 vertebrae lying in front of
laryngopharynx.

4. CONSTITUTION OF LARYNX
 Formed by a cartilaginous skeleton held
together by ligaments.
 At puberty male larynx increases in size
rapidly, and the thyroid cartilage projects
to form the Adam’s apple.

5. CARTILAGES OF LARYNX

6. CARTILAGES OF LARYNX-
EPIGLOTTIS
 Epiglottis-leaf shaped fibro elastic
cartilage and projects behind the base of
the tongue.
 The narrow lower border is attached by
the thyro-epiglottic ligament to the
posterior surface of thyroid alae below
thyroid notch.

7. CARTILAGES OF LARYNX-
THYROID CARTILAGE
 Largest cartilage of larynx with two wings
or alae joined anteriorly in midline.
 Two alae form a right angle between them
in male while in female the angle is
obtuse. the alae project backwards and
have superior and inferior cornu.

8. CARTILAGES OF LARYNX-
CRICOID
 It is signet ring shaped with a broad
lamina posteriorly and narrow arch in
front.
 cricoid, thyroid and epiglottis are unpaired
cartilages of larynx where as
arytenoid,corniculate and cuneiform
cartilages are paired.

9. CARTILAGES OF LARYNX-
ARYTENOID
 Shaped like a pyramid
 Base participates in crico-arytenoid joint.
 Anterior vocal process gives attachment to
vocal cord.
 The lateral mescular process provides
attachment to the posterior and lateral
cricoarytenoid muscles

10. CARTILAGES OF LARYNX-
CORNICULATE & CUNEIFORM
 Corniculate are situated at the apex of the
arytenoids cartilages.
 Cuneiform lie in the aryepiglottic folds,
lateral to the Corniculate cartilages.

11. JOINTS AND LIGAMENTS
 Two synovial joints on either side
1) Cricothyroid joint
2) crico-arytenoid joint
 Intrinsic ligaments
1) Quadrangular membrane
2) Conus elasticus
3) thyro-epiglottic ligament

12.  Extrinsic ligaments
1)Thyrohyoid membrane
2)Medial and lateral thyrohyoid ligament
3)Cricothyroid membrane
4)Cricotracheal membrane

13. MUSCLES OF LARYNX-
INTRINSIC

14. INTRINSIC MUSCLES OF
LARYNX AND THEIR ACTION
 Posterior crico-arytenoid- Abductor
 Lateral crico-arytenoid, inter arytenoid,
thyro arytenoid, cricothyroid- Adductors
 Cricothyroid, vocalis and thyro-arytenoid-
tensors and adductors
 Thyro-epiglottic-Opener of laryngeal inlet
 Interarytenoid, aryepiglottic- Closers of
laryngeal inlet

15. EXTRINSIC MUSCLES
 Strap muscles
 Pharyngeal muscles including inferior
constrictor muscle

16. CAVITY OF LARYNX
 EXTENT- from laryngeal inlet above to
lower border of cricoid cartilage.
 Inlet of larynx communicates with
laryngopharynx.

20. 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
 Length of glottis is about 2.5cm in adult
male and about 7-9mm in a child

21. HISTOLOGY OF LARYNX
 Mucous membrane lines the entire larynx.
 Stratified squamous epithelium lines true
vocal cords and upper parts of vestibule.
 Columnar ciliated epithelium lines rest of
the cavity.
 Mucous glands preset in all parts except
on free edges of vocal cords

22. BLOOD SUPPLY OF LARYNX
 Superior thyroid artery
 Inferior thyroid artery
 Cricothyroid artery

24. NERVE SUPPLY OF LARYNX
 Superior laryngeal nerve-internal branch is
sensory supplies larynx above the level of
vocal cords and external branch supplies
cricothyroid muscle.
 Recurrent laryngeal nerve-motor branch
supplies all muscles of larynx except the
cricothyroid and sensory branch supplies
subglottis.

26. 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

27. LARYNGEAL SPACES
 PRE-EPIGLOTTIC SPACE
 PARAGLOTTIC SPACE
 REINKE’S SPACE

28. ANATOMY OF TRACHEA-
DEVELOPMENT
 Tracheobronchial tree develops from
median tracheobronchial groove.

29. 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.

31. BLOOD SUPPLY
 Mainly by inferior thyroid artery

32. NERVE SUPPLY
 Vegus, recurrent laryngeal nerve and
sympathetic trunk

33. LYMPHATICS
 Pretracheal and paratracheal lymph nodes

34. FUNCTIONS OF
TRACHEOBRONCHIAL TREE
 Respiration
 Protection to lungs
 Warming and moistening of inspired air
 phonation