Anatomy of larynx and trachea final

1. ANATOMY OF LARYNX ANATOMY OF LARYNX
AND TRACHEAAND TRACHEA
DEPT OF DEPT OF
OTORHINOLARYNGOLOGYOTORHINOLARYNGOLOGY
P I M SP I M S

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

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

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

5. CARTILAGES OF LARYNXCARTILAGES OF LARYNX

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

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

8. CARTILAGES OF LARYNX- CARTILAGES OF LARYNX-
CRICOIDCRICOID

It is signet ring shaped with a broad It is signet ring shaped with a broad
lamina posteriorly and narrow arch in lamina posteriorly and narrow arch in
front.front.


cricoid, thyroid and epiglottis are unpaired cricoid, thyroid and epiglottis are unpaired
cartilages of larynx where as cartilages of larynx where as
arytenoid,corniculate and cuneiform arytenoid,corniculate and cuneiform
cartilages are paired.cartilages are paired.

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

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

11. JOINTS AND LIGAMENTSJOINTS AND LIGAMENTS
Two synovial joints on either sideTwo synovial joints on either side
1) Cricothyroid joint1) Cricothyroid joint
2) crico-arytenoid joint2) crico-arytenoid joint

Intrinsic ligamentsIntrinsic ligaments
1) Quadrangular membrane1) Quadrangular membrane
2) Conus elasticus2) Conus elasticus
3) thyro-epiglottic ligament3) thyro-epiglottic ligament

12. 
Extrinsic ligamentsExtrinsic ligaments
1)Thyrohyoid membrane1)Thyrohyoid membrane
2)Medial and lateral thyrohyoid ligament2)Medial and lateral thyrohyoid ligament
3)Cricothyroid membrane3)Cricothyroid membrane
4)Cricotracheal membrane4)Cricotracheal membrane

13. MUSCLES OF LARYNX-MUSCLES OF LARYNX-
INTRINSICINTRINSIC

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

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

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

20. CAVITY OF LARYNXCAVITY OF LARYNX

Divided into three parts by 2 folds of Divided into three parts by 2 folds of
mucus membrane: False cords and True mucus membrane: False cords and True
vocal cordsvocal cords

Parts are Vestibule, ventricle and Parts are Vestibule, ventricle and
subglottic spacesubglottic space

Length of glottis is about 2.5cm in adult Length of glottis is about 2.5cm in adult
male and about 7-9mm in a childmale and about 7-9mm in a child

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

22. BLOOD SUPPLY OF LARYNXBLOOD SUPPLY OF LARYNX

Superior thyroid arterySuperior thyroid artery

Inferior thyroid arteryInferior thyroid artery

Cricothyroid arteryCricothyroid artery

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

26. LYMPHATIC DRAINAGELYMPHATIC DRAINAGE

SUPRAGLOTTIS-pre-epiglottic and upper SUPRAGLOTTIS-pre-epiglottic and upper
deep cervical nodes.deep cervical nodes.

GLOTTIS-Lymphatics are practically GLOTTIS-Lymphatics are practically
absentabsent

SUBGLOTTIS-prelaryngeal and SUBGLOTTIS-prelaryngeal and
pretracheal nodes also lower deep pretracheal nodes also lower deep
cervical nodescervical nodes

27. LARYNGEAL SPACESLARYNGEAL SPACES

PRE-EPIGLOTTIC SPACEPRE-EPIGLOTTIC SPACE

PARAGLOTTIC SPACEPARAGLOTTIC SPACE

REINKE’S SPACEREINKE’S SPACE

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

29. ANATOMY OF TRACHEAANATOMY OF TRACHEA

Tube made up of cartilage and membrane Tube made up of cartilage and membrane
and measures approx 10-11cm in adultand measures approx 10-11cm in adult

Extends from C-6 to T-5Extends from C-6 to T-5

There are 16-20 incomplete cartilaginous There are 16-20 incomplete cartilaginous
rings. In neck 6-7 rings are present.rings. In neck 6-7 rings are present.

31. BLOOD SUPPLYBLOOD SUPPLY

Mainly by inferior thyroid arteryMainly by inferior thyroid artery

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

33. LYMPHATICSLYMPHATICS

Pretracheal and paratracheal lymph nodesPretracheal and paratracheal lymph nodes

34. FUNCTIONS OF FUNCTIONS OF
TRACHEOBRONCHIAL TREETRACHEOBRONCHIAL TREE

RespirationRespiration

Protection to lungsProtection to lungs

Warming and moistening of inspired airWarming and moistening of inspired air

phonationphonation