Musculus genioglossus
The largest intrinsic muscle of the tongue, forming the main body. A fan-shaped muscle that protrudes and depresses the tongue. Critical for food manipulation and swallowing.
Origin: Medial surface of the mandibular symphysis (genial tubercle)
Insertion: Entire length of the tongue from base to tip; also attaches to the basihyoid bone
Action: Protrudes the tongue; depresses the tongue; essential for food gathering and manipulation during eating
Innervation: Hypoglossal nerve (CN XII)
Bilateral hypoglossal nerve damage causes complete tongue paralysis. The tongue hangs from the mouth and the horse cannot eat or drink. Often from guttural pouch pathology affecting CN XII bilaterally
Bilateral hypoglossal nerve damage causes complete tongue paralysis. The tongue hangs from the mouth and the horse cannot eat or drink. Often from guttural pouch pathology affecting CN XII bilaterally. Signs include: Tongue protruding from the mouth; inability to retract the tongue; cannot eat or drink; drooling; rapid weight loss; often accompanied by other cranial nerve deficits.
See the Genioglossus on our interactive 3D horse model. Open 3D Model