Floor Of Fourth Ventricle Anatomy

The roof is composed of the cerebellum located at the back of the brain and the floor is formed by the rhomboid fossa a depression in the brainstem.

Floor of fourth ventricle anatomy.

This ventricle has a roof and a floor. From the 4th ventricle the fluid drains into two places. Lesions may also arise outside the ventricle and secondarily extend into this chamber including medullary tectal and cerebellar hemispheric masses. Central spinal canal bathes the spinal cord.

The obex is the most caudal tip of the fourth ventricle. The glistening white floor of the fourth ventricle is the posterior surface of the brain stem fig. The fourth ventricle outlet obstruction fvoo is a rare but well established cause of obstructive tetra ventricular hydrocephalus characterizing with dilatation or large cerebrospinal fluid collection of the foramen of magendie and foramen of luschka. Tumors of the fourth ventricle commonly originate from the following structures composing the floor.

The border between the pons and medulla occurs approximately at the level of the foramina of luschka. The fourth ventricle has a roof at its upper posterior surface and a floor at its lower anterior surface and side walls formed by the cerebellar peduncles nerve bundles joining the structure on the posterior side of the ventricle to the structures on the anterior side. Its rhomboid in shape diamond shaped and as a result of its shape the floor of the 4th ventricle is usually referred to as rhomboid fossa. The floor located ventrally is formed by the rhomboid fossa a diamond shaped depression on the dorsal surface of the pons and upper half of the medulla.

It lies within the brainstem at the junction between the pons and medulla oblongata. The floor of the fourth ventricle is also referred to as the rhomboid fossa because of its shape. Each half is further subdivided by sulcus limitans into a medial area called medial eminence and lateral vestibular area. The floor of fourth ventricle is divided into two symmetrical halves by the median sulcus.

It s divisible into 2 parts. Hydrocephalus is classified as noncommunicating and communicating based on whether all ventricular and subarachnoid spaces are communicating. The superior pontine part of the floor begins at the aqueduct and expands to the lower margin of the cerebellar peduncles. The sidewalls are formed by the veli and cerebellar peduncles.

In the pontine part of floor of fourth ventricle following features are seen. The upper triangular part is formed by the posterior surface of the pons. It is divisible into a right and left half by the posterior median sulcus and into a superior and inferior triangle by the striae medullares. The ependyma choroid plexus and tela choroidea.