Which muscle is the primary protruder (protrusion) of the tongue?

The genioglossus is the largest and most important extrinsic tongue muscle. Its anterior fibers depress the tongue tip, its middle fibers protrude the tongue (stick it out), and its posterior fibers retract the tongue. It is innervated by the hypoglossal nerve (CN XII). Clinical relevance: In unconscious or sedated patients, loss of genioglossus tone causes the tongue to fall posteriorly and obstruct the airway — this is why the chin-lift/jaw-thrust maneuver is essential in airway management. Hyoglossus depresses the tongue. Styloglossus retracts and elevates the sides of the tongue. Palatoglossus elevates the posterior tongue and is innervated by CN X.