The trachea is cartilaginous tube which connects pharynx and larynx to lungs and thus allowing passage of air.
C-shaped cartilages are open at area where trachea is nearest esophagus, which leads from throat to stomach. <u>It reinforces anterior and lateral sides of trachea to maintain airway open.</u>
The trachealis muscle bridges gap between free ends of the C-shaped cartilages at posterior border of trachea and is adjacent to esophagus. <u>The primary function of trachealis muscle is to constrict trachea, allowing the air to be expelled with more force during coughing. </u>
