Anatomy Of Larynx t3h1

Anatomy of Larynx Dr. Prashant Yarlagadda

Function

• Sphincter at inlet of air ages. • Organ of Phonation.

Location • Extent  Tongue → Trachea.

• Projects ventrally between great vessels of neck. • Anterior coverings  Skin  Fasciae  Hyoid depressor muscles

• Opposite to C3 → C6 vertebrae (adult male)

General features • Opens into  Above – Laryngopharynx  Below – Trachea

• Mobile on deglution

Size • Same in males and females till puberty. • Enlarges considerably in males after puberty. Male Female  Thyroid cartilage age 40 years. Length 44grows mm till 36 mm Transverse 43 mm 41 mm Sagittal 36 mm 26 mm

Surface anatomy C3

Body of hyoid

C3 – C4 junction

Upper border of thyroid cartilage

C4 – C5 junction

Thyroid cartilage

C6

Cricoid cartilage

Cartilages Unpaired Cricoid Thyroid Epiglottic

Paired Arytenoid Cuneiform Corniculate Tritiate

Cartilages Hyaline cartilage Thyroid Cricoid Most of arytenoid

Elastic fibro-cartilage Corniculate Cuneiform Tritiate Epiglottic Apex of arytenoid

• Hyaline cartilage – calcify with age. • Elastic cartilage – do not calcify with age.

Cartilages

Thyroid cartilage • Largest laryngeal cartilage • Two quadrilateral laminae  Anterior borders fused  Posterior borders diverge Prolonged horns Superior cornu Inferior cornu

Thyroid Cartilage •

Laminae  Internal surface smooth  Covered by mucosa  Attachments to angle of laminae  Ligaments  Thyro-epiglottic  Vestibular  Vocal  Muscles  Thyro-arytenoid  Thyro-epiglottic  Vocalis

Thyroid cartilage • Laminae  Superior border Thyro-hyoid membrane

• Angle between laminae  Men - 90⁰  Women - 120⁰

• Shallower angle  Larger laryngeal prominenece  Lengthier vocal cords  Deeper pitch voice

Cricoid • Only ring shaped laryngeal cartilage • Attahcments  Below  Trachea

 Above  Thyroid cartilage  Arytenoid cartilages

• Parts  Anterior – narrow curved arch  Posterior – broad flat lamina

Cricoid • Cricoid arch  Palpable below laryngeal prominence  Separated by depression Contains crico-vocal membrane

Cricoid •

Cricoid lamina  Junction of lamina and arch  facet for inf. thyroid cornu  Inferior border  crico-tracheal ligament  Superior border  Anterio-laterally – cricothyroid membrane.  Postero-superior  facet for arytenoid cartilage

Cricoid • Internal surface  smooth.  lined by mucosa.

Epiglottis • Thin, leaf like • Projects upwards behind tongue and hyoid • Stalk attached to back of laryngeal prominence by thyro-epiglottic ligament

Epiglottis • •

Lateral attachments  Ary-epiglottic folds Upper anterior surface  Non-stratified keratinized squamous epithelium  Reflections  Post tongue Median glosso-epiglottic fold  Post tongue and lateral pharyngeal wall  Lateral glosso-epiglottic folds  Depressions in between – vallecula.

Epiglottis • Anterior space between epiglotts  Hyoid  Thyroid cartilage Pre-epiglottic space  Thyro-hyoid membrane (adipose tissue)

• Posterior surface  Ciliated respiratory mucosa

Epiglottis • Function  Bent posteriorly during deglutition  Food bolus splits and slips into pyriform fossae  Not essential for swallowing Minimal aspiration even if destroyed.

•

Arytenoid

Articulate on  supero-lateral portion of cricoid lamina. • Pyramidal  Surfaces – three  Posterior Muscular process  Antero-Lateral  Vestibular ligament  Vocal process  Medial  Mucosa  Lateral boundary of intercatilaginous part or rima glottidis

Arytenoid • Processes – two  Vocal  Antero-lateral surface  Attachment - Vocalis

 Muscular  Posterior surface  Attachment – Muscles

• Base  Articulates - Cricoid

• Apex  Articulates Corniculate

Corniculate • Conical nodules • Articulate with  Arytenoid

• Constitute  Posterior part of aryepiglottic folds.

Cuneiform • Located in  Ary-epiglottic fold whitish elevation through mucosa  Antero-superior to corniculate • Elongated, club-like nodule