Floor Of Fourth Ventricle Cranial Nerve

The anterior median sulcus along the midline of the anterior medulla divides two longitudinal eminences called the pyramids this sulcus is obscured by small fiber bundles in the pyramidal decussation near the junction of the medulla and the spinal cord.

Floor of fourth ventricle cranial nerve.

The only naturally occurring openings between the ventricles of the brain and the subarachnoid space surrounding the brain are the foramina of luschka and magendie in the fourth ventricle. Each half is further subdivided by sulcus limitans into a medial area called medial eminence and lateral vestibular area. A lower triangular part formed by the upper part of the posterior surface of the medulla. The obex is also a.

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. The pontine tegmentum contains nuclei of the cranial nerves trigeminal 5th abducens 6th facial 7th and vestibulocochlear 8th cranial nerve nuclei. The medulla the pons and the midbrain are located just behind the basilar part of the occipital bone and the dorsum sellae. Medial eminence show an elevation called facial colliculus produced by the fibers of facial nerve which form a loop around the dorsal aspect of abducent nucleus.

74 76 the responses from muscles innervated by cranial nerves vii ix x and xii can be recorded during surgery as the neurosurgeon stimulates the floor of the fourth ventricle with a. In the pontine part of floor of fourth ventricle following features are seen. The dorsal aspect of the medulla faces almost directly backwards. The back of the upper part of the medulla forms the floor of the fourth ventricle.

Two male patients ages 8 and 10 years presented to the emergency department and had brain magnetic resonance imaging mri scans showing brainstem fourth ventricle tumors. Lab 3 the ventricles and blood supply cranial nerves of the medulla. Functional mapping of the fourth ventricular floor has allowed the identification of brain stem cranial nerve motor nuclei and their relationship to the tumor. The caudal tip of the fourth ventricle where it becomes the central canal is known as the obex.

On the model this is the fourth ventricle this is the floor. The floor of the fourth ventricle the rhomboid fossa see fig. Multiple cranial nerve nuclei are located on the floor of the fourth ventricle with a high risk of permanent damage. The floor of the fourth ventricle often called the rhomboid fossa because of its shape is divisible into an upper triangular part formed by the posterior surface of the pons.

However the floor is the most related part to the cranial nerve nuclei.