Larynx

• Extends from the root of the tongue to the trachea.
• It is situated approximately at C3, C4, C5 and C6 vertebrae.

Relationships

• Above - it opens into the laryngeal part of the pharynx

• Below - Continues with the trachea at the level of cricoid cartilage

• Arteriorly - Skin and fascia

• Laterally - Carotid vessels

• Posteriorly - Pharynx

It is formed by multiple cartilages and it is lined by mucus membrane. It is an organ of phonation and also plays an important part in air passage into the trachea and acts as a sphincter.

Laryngeal Cartilages

• Thyroid cartilage - largest 'V' shaped (forms the Adam's Apple)
  • Articulates with Cricoid cartilage - 'Signet Ring' shaped
• Arytenoid cartilages sit within the cricoid
• Corniculate - small
• Cuneiform - small

Cartilage of Epiglottis

• It is a thick fibrocartilage which projects in front of the entrance to the larynx.
•  It is attached to the thyroid cartilage and the arytenoid cartilage. 
• The superior part is free and it is lined with mucous membranes.
• Epiglottis is attached to arytenoid cartilage by the aryepiglottis folds.
• The thryoid, cricoid and most of the arytenoid cartilages calcify and ossify and are visible radiographically.

Vocal Cords

• The vocal cords meet anteriorly in the midline. 
• They are adducted by thyroarytenoid muscles and abducted by cricoarytenoid muscles.