Glottis is opening covered by epiglottis during swallowing of food. If food, etc. passes epiglottis into larynx, reflex coughing usually expels it. Mucous membrane folds supported by elastic ligaments. Occur at edges of glottis. Vibrate as air is expelled past them through the glottis.
Pitch is due to length, thickness, elasticity, and tension of vocal cords.
At puberty, larynx and vocal cords grow more rapidly in males. Windpipe a. Tube held open by C-shaped cartilaginous rings. Contains cilia projecting from epithelium of trachea to keep lungs clean by sweeping debris toward throat. Mucus secreted to embed and transport debris. Bronchus leads to right and left lungs.