Anatomy of Larynx

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