BRAIN PLASTICITY

Brain plasticity

Brain plasticity

The brain constitutes the central nervous system of the body. Apart from the brain the central nervous system also contains the spinal cord.

Brain is suspended in the fluid called the cerebrospinal fluid, which protects the brain, and the bones of the skull also protect it. Brain is composed of large number of nerve cells and their processes which are supported by specialized tissue called neuroglia.neuron is the name given to nerve cells and its processes. The interior of the brain is organized into gray and white matter. Grey matter consists of nerve cells and the proximal portion of their processes embedded in neuroglia.white matter consists of nerve fibers embedded in neuroglia.The brain lies in the cranial cavity and is continuous with the spinal cord through the foramen magnum. It is surrounded by three meninges the duramater, the arachnoid mater and the pia mater and these are continous with the corresponding meninges of the spinal cord.

The brain is conventially divided intio three major divisions. These are in ascending order from the spinal cord, the rhombencephlon or hindbrain, the mesencephalon or midbrain and the prosencephalon or forebrain. The rhombencephalon may be subdivided into myelencephalon or medulla oblongata, the metencephalon or pons and the cerbellum.the prosencephalon may also be subdivided into the diencephalons which is the central part of the forebrainand the telencephalion or cerebrum. The brainstem( combined term for medulla oblongata,pons and midbrain) is that part of the brain that remains after the cerbral hemispheres and cerebellum are removed.The hindbrain consists of medulla oblongata, the pons and the cerebellum.

The medulla oblongata is conical in shape and connects the pons superiorly to the spinal cord inferiorly. A median fissure is present on the anterior surface of the medulla, and on each side of this fissure is a swelling called the pyramid. Posterior to the pyramids are the olives, which are oval elevations, produced by the underlying olivary nuclei. Posterior to the olives are the inferior cerebellar peduncles, which connect the medulla to the cerebellum. On the posterior surface of the inferior part of the medulla oblongata are the gracile and cuneate tubercles, produced by the medially placed underlying nucleus gracilis and the laterally placed nucleus cuneatus.Pons is situated on the anterior surface of the cerebellum inferior to the midbrain and superior to the medulla oblongata. It is much greater in anteroposterior and transverse dimensions than the medulla. The pons or bridges derives its name from the large no of transverse fibers on its anterior aspect connecting the two-cerebellar hemispheres.

The cerebellum lies within the posterior cranial fossa posterior to the pons and the medulla oblongata. It consists of two hemispheres connected by a median portion, the vermis. The cerebellum is connected to the midbrain by the superior cerebellar peduncles, to the pons by the middle cerebellar peduncles and to the medulla by the inferior cerebellar peduncles. The surface layer of each cerebellar hemisphere is called the cortex and is composed of gray matter. The cerebellar cortex is thrown into folds or ...