Which muscle directly contributes to preventing the tongue from obstructing the airway?

The genioglossus muscle plays a crucial role in preventing the tongue from obstructing the airway. This muscle is primarily responsible for the movement of the tongue, particularly its ability to protrude and lower the tongue. By anchoring the tongue in a position that keeps it from falling back into the oropharynx, the genioglossus muscle helps maintain an open airway during sleep and in various positions.

When the genioglossus contracts, it draws the tongue forward, which is essential in situations where airway blockage could occur, such as in individuals with a relaxed airway or those suffering from sleep apnea. Its anatomical positioning and its function make it vital in ensuring that the airway remains unobstructed, especially during sleep, when muscle tone in the throat tends to decrease.

Other muscles mentioned, while important for various tongue and oral functions, do not primarily focus on keeping the airway clear in the same manner as the genioglossus does. Thus, the genioglossus is the correct answer for preventing obstruction of the airway by the tongue.