Larynx

Dr Laxman KhanalAssistant Professor, Department of Anatomy

BPKIHS, DharanPBL –Resource session

06-03-2017

Introduction

• It is organ of phonation.

• Inlet for lower respiratory passage

• Has role in deglutition with pharynx

• Lies in anterior midline of neck.

• Extends from C3-C6 level.

• Length – 3.5-4.5 cm

• Contains- cartilages

- joints, membranes and ligaments

- muscles

Cartilages of larynx

Ligaments1. Extrinsic ligamentsa. Thyrohyoid membraneb. Thyroepiglottic ligamentsc. Hyoepiglottic ligamentsd. Cricotracheal ligaments2. Intrinsic ligamentsa. Crico-thyroid membrane (Quadrangular membrane)b. Vestibular ligamentc. Vocal ligamentsd. Cricovocal membrane (Conus elasticus)

Components of larynx• Cartilages: 3 paired + 3 unpaired• Ligaments: extrinsic + intrinsic • Bone: Hyoid• Muscles: extrinsic + Intrinsic

Skeleton of larynxThree median cartilagesThree bilateral cartilages

+Hyoid bone

Parts of thyroid cartilageMembranes

Thyro-hyoid membrane

Superior laryngeal vessels Internal laryngeal nerve

Hyoepiglottic membraneThyroepiglottic membraneThyrohyoid membraneCricotracheal membrane

Parts of thyroid cartilageParts of cricoid cartilageArytenoid cartilage

Lamina Cornu

Lamina

Lets focus on vocal process of arytenoid cartilage to understand intrinsic ligaments

• Vocal process• Muscular process• Vocal ligament• Vestibular ligament

QM

CE

Vestibule of larynx

Sinus or ventricle of larynx

Infraglottic part of larynx

Ventricle of larynxRima glottidisRima vestibuliHeimlich Maneuver

Passage of food and air in laryngopharynxInlet of larynxPyriform fossa

• Inlet of larynx• Pyriform fossa

1. Digastric muscle2. Stylohyoid muscle3. Palatopharyngeu4. Stylopharyngeus5. Thyrohyoid6. Sternothyroid

Extrinsic muscle of larynx

Intrinsic Muscles of Larynx

To understand the functions of musclesThink about !!!!1. The antero-posterior movement of epiglottis.2. The distance between thyroid and arytenoid

cartilage.3. Movement of two arytenoid with each other.

• Muscular process• Vocal process

Crico-Thyroid

Tensor of vocal cord

• Transverse/oblique arytenoid• Ary-epiglotticus• Thyroepiglotticus

Posterior crico-arytenoid

Lateral crico-arytenoid- Adductor of vocal cord

• Vocalis- relaxor• Thyro-arytenoid – relaxor

Rima glottidis and phonationIntermembranous partIntercartilagenous part

Singer’s noduleTeacher’s nodule !!!

Nerve supply Motor supply: recurrent laryngeal nerveexcept cricothyroid, which is supplied by theexternal laryngeal nerve.

Nerve supply Motor supply: recurrent laryngeal nerveexcept cricothyroid, which is supplied by theexternal laryngeal nerve.

Sensory supply: internal laryngeal nerveand recurrent laryngeal nerve.Demarcation: Vocal fold

Blood supplySuperior laryngeal vesselsInferior laryngeal vesselsDemarcation: vocal fold

Blood supply/ sensory supplySup laryngeal vessel/ internal laryngeal nerveInf laryngeal vessel/ recurrent laryngeal nerve

Lymphatic drainageUpper deep cervicalVocal foldLower deep cervical

Internal laryngeal nerve block: to abolish the cough reflex during bronchoscopy and laryngoscopy