The facial colliculus is an elevated area located in the

pontine tegmentum Pontine may refer to: * Having to do with the pons, a structure located in the brain stem (from ''pons'', "bridge") * Pontine Marshes, a region of Italy near Rome * Pontine Islands The Pontine Islands (, also ; it, Isole Ponziane ) are an ar ...

(dorsal pons), within the floor of the

fourth ventricle The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ve ...

(i.e. the

rhomboid fossa The rhomboid fossa is a rhombus-shaped depression that is the anterior part of the fourth ventricle. Its anterior wall, formed by the back of the pons and the medulla oblongata, constitutes the floor of the fourth ventricle. It is covered by a th ...

). It is formed by fibres from the

facial motor nucleus The facial motor nucleus is a collection of neurons in the brainstem that belong to the facial nerve ( cranial nerve VII). These lower motor neurons innervate the muscles of facial expression and the stapedius. Structure The nucleus is situate ...

looping over the

abducens nucleus The abducens nucleus is the originating nucleus from which the abducens nerve (VI) emerges—a cranial nerve nucleus. This nucleus is located beneath the fourth ventricle in the Anatomical terms of location, caudal portion of the pons, Anatomical t ...

. The facial colliculus is an essential landmark of the rhomboid fossa.

Anatomy

The facial colliculus occurs within the rhomboid fossa (i.e. the floor of the fourth ventricle) where it is placed lateral to its (midline) median sulcus.

Structure

The facial colliculus is formed by brachial motor nerve fibres of the facial nerve (CN VII) looping over the (ipsilateral)

, forming a bump upon the surface.

Clinical significance

A facial colliculus lesion would result in ipsilateral facial

paralysis Paralysis (also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 ...

(i.e.

Bell's palsy Bell's palsy is a type of facial paralysis that results in a temporary inability to control the facial muscles on the affected side of the face. In most cases, the weakness is temporary and significantly improves over weeks. Symptoms can vary fr ...

) and inhibited ipsilateral and unopposed contralateral eye deviation.

Additional images

File:Pons section at facial colliculus.png, Axial section of the Brainstem (Pons) at the level of the Facial Colliculus File:Slide2PITER.JPG, Fourth ventricle. Posterior view.Deep dissection.

References

External links

* http://www.med.yale.edu/caim/cnerves/cn6/cn6_2.html * https://web.archive.org/web/20130930042036/http://www.neuroanatomy.wisc.edu/virtualbrain/BrainStem/14CNVII.html * https://web.archive.org/web/20070927162218/http://www.ib.amwaw.edu.pl/anatomy/atlas/image_04be.htm Pons {{neuroanatomy-stub