Question

During inspiration the air pressure in the pharynx is _____.

		lower than atmospheric pressure
		higher than atmospheric pressure
		equal to atmospheric pressure

Answer 1

The upper respiratory tract include nasal cavity, pharynx and larynx. Normally in patent airways, the pressure drops in the upper airway tract are quite small and physiologically unimportant.

During inspiration the pressure inside the pharynx drops which result in the activation of pharyngeal dilator muscles( genioglossus muscle ) by displacing the hyoid bone and the tongue anteriorly. This helps to preserve the pharyngeal dilation and to reduce the airway resistance.

Thus the answer is During inspiration the air pressure in the pharynx is decreased.