The larynx sits at the top of the trachea in the front of the neck. It guards the lower airway, makes sound and leads into the trachea, a firm tube held open by rings of cartilage.
Cartilages
The thyroid cartilage forms the Adam's apple, and the ring-shaped cricoid cartilage sits just below it. The cricothyroid membrane between them is a thin spot used for an emergency surgical airway.
Epiglottis and vocal cords
The epiglottis is a leaf-shaped flap that covers the larynx during swallowing. Below it the vocal cords open for breathing and close to make sound and protect the airway; the gap between them is called the glottis.
Cough reflex
The larynx is very sensitive. Anything that touches it triggers a strong cough or a spasm of the vocal cords (laryngospasm) to keep material out of the lungs.
Trachea
The trachea runs about 10 to 12 cm from the larynx to the carina, where it splits into the two main bronchi. C-shaped cartilage rings hold it open in front, and its soft back wall lies against the esophagus.
At the bedside
During intubation the tube passes between the vocal cords, and its tip should sit a few centimeters above the carina. A tube placed too deep usually enters the right main bronchus, so check for equal breath sounds on both sides.
Related guides
Written by Making Synapses. Topic reference: OpenStax, Anatomy and Physiology 2e (no text adapted).