Anatomyof

Larynx

Larynx (anterior)

Larynx (posterior)

Larynx (posterior)

Larynx (lateral)

Larynx (superior)

Larynx (superior)

Larynx (sagittal section)

Larynx (sagittal section)

Larynx (coronal section)

Vocal fold

Vocal fold

Laryngeal Cartilages

3 single & 3 paired

Single Paired

Epiglottis Arytenoid

Thyroid Corniculate (Santorini)

Cricoid Cuneiform (Wrisberg)

Cartilages (anterior)

Laryngeal Cartilages

Cartilages (posterior)

Cartilages (posterior)

Cartilage Histology

Elastic: Epiglottis, corniculate, cuneiform &

apex of arytenoid. Little or no calcification.

Hyaline: Thyroid, cricoid & remaining arytenoid.

Calcify as age advances. Ossification begins by

25-30 yr & is completed by 60 yr.

Indirect Laryngoscopy

Flexible LaryngoscopyLEFT RIGHT

Laryngeal cavity

1. Laryngeal inlet

2. Laryngeal Vestibule

3. Laryngeal Ventricle

4. Rima glottis

5. Subglottis

Pediatric Larynx

• Conical in shape & subglottis is narrowest part

• Positioned high (C3-C4)

• Moves higher during swallowing allowing

simultaneous breathing & feeding

• Loose sub-mucosal tissues (swell up easily)

• Soft cartilages that collapse easily

Membranes & Ligaments

• Extrinsic:

connect thyroid cartilage & epiglottis with

hyoid bone; cricoid cartilage with trachea.

• Intrinsic:

connect cartilages of larynx to each other.

Extrinsic

• Thyrohyoid

membrane

• Hyoepiglottic

ligament

• Cricotracheal

ligament

Intrinsic

Intrinsic

Intrinsic

1. Quadrangular membrane

Ary-epiglottic ligament Vestibular ligament

2. Crico-vocal membrane

Vocal ligament Cricothyroid membrane

3. Thyro-epiglottic ligament

Oncological Divisions

A. Supraglottis: laryngeal

inlet to apex of ventricle

B. Glottis: apex of

ventricle to 10 mm below

C. Subglottis: lower glottic

border to lower cricoid

border

Subsites

A. Supraglottis: 1. Epiglottis 2. Aryepiglottic

folds 3. Ventricular bands 4. Laryngeal

Ventricle

B. Glottis: 1. True vocal cords 2. Anterior

commissure 3. Posterior commissure

C. Subglottis

Intrinsic Muscles

A. Acting on vocal cords

Abduction Posterior crico-arytenoideus

Adduction Lateral crico-arytenoideus

Transverse inter-arytenoideus

Thyro-arytenoideus externa

Tension + lengthening Cricothyroid

Relaxation + shortening Vocalis

Intrinsic Muscles

B. Acting on laryngeal inlet

Opener Thyro-epiglottic

Closer Oblique inter-arytenoideus

Ary-epiglottic

Extrinsic MusclesPrimary Elevators Secondary Elevators

Stylopharyngeus Mylohyoid

Salpingopharyngeus Stylohyoid

Palatopharyngeus Geniohyoid

Thyrohyoid Digastric

Depressors

Sternohyoid Sternothyroid Omohyoid

Posterior cricoarytenoid

Lateral cricoarytenoid

Transverse Inter-arytenoid

Cricothyroid

Thyroarytenoid externa + Vocalis

Oblique Inter-arytenoid

Spaces of Larynx

Reinke’s space

Pre-epiglottic space

Para-glottic space

Communications

Shape of Glottis

Shape of Glottis

Quiet Respiration Forced Inspiration

Inspiration

Shape of Glottis

Normal voice Whisper

Normal phonation

Whisper

Mucous Membrane

• Stratified squamous epithelium:

Epiglottis (anterior surface + upper half of

posterior surface), upper part of aryepiglottic

folds & vocal cords

• Pseudo-stratified ciliated columnar

(respiratory) epithelium:

Rest of laryngeal mucous membrane

Nerve Supply

Superior Laryngeal Nerve:

• Internal: sensation to supraglottis & glottis

• External: motor to cricothyroid muscle

Recurrent Laryngeal Nerve:

• sensation to subglottis

• motor to all intrinsic muscles but cricothyroid

Blood Supply

Arterial supply:

• Laryngeal br. of superior & inferior thyroid

Venous drainage:

• Superior thyroid vein internal jugular vein

• Inferior thyroid vein innominate vein

Lymphatic Drainage

Supraglottis: via thyrohyoid membrane into upper

deep cervical nodes & thyroid gland

Subglottis: via cricothyroid membrane into

pretracheal + lower deep cervical nodes

Glottis: has no lymphatics