Facial colliculus

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Facial colliculus

The facial colliculus is an anatomical feature located in the brainstem, specifically on the dorsal aspect of the pons. It is a notable landmark in the floor of the fourth ventricle and is formed by the fibers of the facial nerve (cranial nerve VII) as they loop around the abducens nucleus (cranial nerve VI).

Anatomy

The facial colliculus is situated in the rhomboid fossa, which is the floor of the fourth ventricle. It is created by the internal genu of the facial nerve, where the fibers of the facial nerve loop over the abducens nucleus before exiting the brainstem. This looping creates a bulge that is visible on the surface of the pons.

Function

The facial colliculus is primarily associated with the pathways of the facial and abducens nerves. The facial nerve is responsible for innervating the muscles of facial expression, while the abducens nerve controls the lateral rectus muscle of the eye, which is involved in eye movement.

Clinical Significance

Lesions or damage to the facial colliculus can result in a combination of symptoms due to the involvement of both the facial and abducens nerves. This can lead to facial paralysis and strabismus (misalignment of the eyes). Such conditions are often evaluated using imaging techniques like MRI to assess the integrity of the brainstem structures.

Related Structures

• Fourth ventricle
• Pons
• Facial nerve
• Abducens nerve
• Rhomboid fossa

See Also

• Brainstem
• Cranial nerves
• Neuroanatomy