ANATOMY OF LARYNX ANATOMY OF LARYNX AND TRACHEAAND TRACHEA

DEPT OF DEPT OF OTORHINOLARYNGOLOGYOTORHINOLARYNGOLOGY

P I M SP I M S

DEVELOPMENT OF LARYNXDEVELOPMENT OF LARYNX

Larynx develops from the Larynx develops from the tracheobroncheal groove which is tracheobroncheal groove which is ventral midline respiratory ventral midline respiratory diverticulum of the foregut.diverticulum of the foregut.

Epiglottis and the Thyroid cartilage Epiglottis and the Thyroid cartilage develop from the fourth branchial develop from the fourth branchial arch.arch.

SITUATION OF LARYNXSITUATION OF LARYNX

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

CONSTITUTION OF LARYNXCONSTITUTION OF LARYNX

Formed by a cartilaginous skeleton Formed by a cartilaginous skeleton held together by ligaments.held together by ligaments.

At puberty male larynx increases in At puberty male larynx increases in size rapidly, and the thyroid cartilage size rapidly, and the thyroid cartilage projects to form the Adam’s apple.projects to form the Adam’s apple.

CARTILAGES OF LARYNXCARTILAGES OF LARYNX

CARTILAGES OF LARYNX-CARTILAGES OF LARYNX-EPIGLOTTISEPIGLOTTIS

Epiglottis-leaf shaped fibro elastic Epiglottis-leaf shaped fibro elastic cartilage and projects behind the cartilage and projects behind the base of the tongue.base of the tongue.

The narrow lower border is attached The narrow lower border is attached by the thyro-epiglottic ligament to by the thyro-epiglottic ligament to the posterior surface of thyroid alae the posterior surface of thyroid alae below thyroid notch.below thyroid notch.

CARTILAGES OF LARYNX-CARTILAGES OF LARYNX-THYROID CARTILAGETHYROID CARTILAGE

Largest cartilage of larynx with two Largest cartilage of larynx with two wings or alae joined anteriorly in wings or alae joined anteriorly in midline.midline.

Two alae form a right angle between Two alae form a right angle between them in male while in female the angle them in male while in female the angle is obtuse. the alae project backwards is obtuse. the alae project backwards and have superior and inferior cornu. and have superior and inferior cornu.

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 cricoid, thyroid and epiglottis are

unpaired cartilages of larynx where unpaired cartilages of larynx where as arytenoid,corniculate and as arytenoid,corniculate and cuneiform cartilages are paired.cuneiform cartilages are paired.

CARTILAGES OF LARYNX-CARTILAGES OF LARYNX-ARYTENOIDARYTENOID

Shaped like a pyramidShaped like a pyramid Base participates in crico-arytenoid Base participates in crico-arytenoid

joint.joint. Anterior vocal process gives Anterior vocal process gives

attachment to vocal cord.attachment to vocal cord. The lateral mescular process provides The lateral mescular process provides

attachment to the posterior and attachment to the posterior and lateral cricoarytenoid muscleslateral cricoarytenoid muscles

CARTILAGES OF LARYNX-CARTILAGES OF LARYNX-CORNICULATE & CUNEIFORMCORNICULATE & CUNEIFORM

Corniculate are situated at the apex Corniculate are situated at the apex of the arytenoids cartilages.of the arytenoids cartilages.

Cuneiform lie in the aryepiglottic Cuneiform lie in the aryepiglottic folds, lateral to the Corniculate folds, lateral to the Corniculate cartilages.cartilages.

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

Extrinsic ligamentsExtrinsic ligaments

1)Thyrohyoid membrane1)Thyrohyoid membrane

2)Medial and lateral thyrohyoid 2)Medial and lateral thyrohyoid ligamentligament

3)Cricothyroid membrane3)Cricothyroid membrane

4)Cricotracheal membrane4)Cricotracheal membrane

MUSCLES OF LARYNX-MUSCLES OF LARYNX-INTRINSICINTRINSIC

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-Cricothyroid, vocalis and thyro-

arytenoid- tensors and adductorsarytenoid- tensors and adductors Thyro-epiglottic-Opener of laryngeal inletThyro-epiglottic-Opener of laryngeal inlet Interarytenoid, aryepiglottic- Closers of Interarytenoid, aryepiglottic- Closers of

laryngeal inletlaryngeal inlet

EXTRINSIC MUSCLESEXTRINSIC MUSCLES

Strap musclesStrap muscles

Pharyngeal muscles including inferior Pharyngeal muscles including inferior constrictor muscleconstrictor muscle

CAVITY OF LARYNXCAVITY OF LARYNX

EXTENT- from laryngeal inlet above EXTENT- from laryngeal inlet above to lower border of cricoid cartilage.to lower border of cricoid cartilage.

Inlet of larynx communicates with Inlet of larynx communicates with laryngopharynx.laryngopharynx.

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 mucus membrane: False cords and True vocal cordsTrue vocal cords

Parts are Vestibule, ventricle and Parts are Vestibule, ventricle and subglottic spacesubglottic space

Length of glottis is about 2.5cm in Length of glottis is about 2.5cm in adult male and about 7-9mm in a adult male and about 7-9mm in a childchild

HISTOLOGY OF LARYNXHISTOLOGY OF LARYNX

Mucous membrane lines the entire Mucous membrane lines the entire larynx.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

BLOOD SUPPLY OF LARYNXBLOOD SUPPLY OF LARYNX

Superior thyroid arterySuperior thyroid artery

Inferior thyroid arteryInferior thyroid artery

Cricothyroid arteryCricothyroid artery

NERVE SUPPLY OF LARYNXNERVE SUPPLY OF LARYNX

Superior laryngeal nerve-internal branch Superior laryngeal nerve-internal branch is sensory supplies larynx above the is sensory supplies larynx above the level of vocal cords and external branch level of vocal cords and external branch supplies cricothyroid muscle.supplies 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 cricothyroid and sensory branch supplies subglottis.supplies subglottis.

LYMPHATIC DRAINAGELYMPHATIC DRAINAGE

SUPRAGLOTTIS-pre-epiglottic and SUPRAGLOTTIS-pre-epiglottic and upper deep cervical nodes.upper 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

LARYNGEAL SPACESLARYNGEAL SPACES

PRE-EPIGLOTTIC SPACEPRE-EPIGLOTTIC SPACE

PARAGLOTTIC SPACEPARAGLOTTIC SPACE

REINKE’S SPACEREINKE’S SPACE

ANATOMY OF TRACHEA-ANATOMY OF TRACHEA-DEVELOPMENTDEVELOPMENT

Tracheobronchial tree develops from Tracheobronchial tree develops from median tracheobronchial groove.median tracheobronchial groove.

ANATOMY OF TRACHEAANATOMY OF TRACHEA

Tube made up of cartilage and Tube made up of cartilage and membrane and measures approx 10-membrane and measures approx 10-11cm in adult11cm in adult

Extends from C-6 to T-5Extends from C-6 to T-5 There are 16-20 incomplete There are 16-20 incomplete

cartilaginous rings. In neck 6-7 rings cartilaginous rings. In neck 6-7 rings are present.are present.

BLOOD SUPPLYBLOOD SUPPLY

Mainly by inferior thyroid arteryMainly by inferior thyroid artery

NERVE SUPPLYNERVE SUPPLY

Vegus, recurrent laryngeal nerve and Vegus, recurrent laryngeal nerve and sympathetic trunk sympathetic trunk

LYMPHATICSLYMPHATICS

Pretracheal and paratracheal lymph Pretracheal and paratracheal lymph nodesnodes

FUNCTIONS OF FUNCTIONS OF TRACHEOBRONCHIAL TREETRACHEOBRONCHIAL TREE

RespirationRespiration Protection to lungsProtection to lungs Warming and moistening of inspired Warming and moistening of inspired

airair phonationphonation