The Phenomenon: The Central Nervous System

The nervous system consists of two divisions; the central nervous system and the peripheral nervous system. The central nervous system is the combination of the nerves within the skull and spine, while the peripheral nervous system is the nervous system that goes everywhere inside (autonomic nervous system) and outside (somatic nervous system) around the body except skull and spine.

The somatic nervous system has two kinds of nerves; afferent nerves that carry sensory signals from the external parts of the body to center, and efferent nerves which carry motor signals from central nervous system to muscular system. The autonomic nervous system also has afferent and efferent nerves and afferent nerves carry sensory signals from internal organs

İt carries signals between the rest of the brain and the body. It is a complex network of about 100 tiny nuclei that occupies the central core of the brain stem from the posterior boundary of the myelencephalon to the anterior boundary of the midbrain. It is involved in a variety of functions, including sleep, attention, movement, the maintenance of muscle tone and various cardiac, circulatory and respiratory reflexes. Metencephalon, also houses a complex network like the myelencephalon. This network like structure create a bulge called the pons. The pons is one major division of the metencephalon, while the other is cerebellum. The cerebellum is the large, convoluted structure on the brain stem’s dorsal surface. Cerebellar damage eliminates the ability to precisely control one’s movements and to adapt them to changing conditions. The other part is Mesencephalon, which also has two divisions like the metencephalon. These parts are “tectum” and “tegmentum”. Tectum is responsible of visual and auditory function. The tegmentum, by the way, plays the role in mediating the pain-reducing effects of opiate drugs and regulating the sensorimotor

The human brains have convolutions and they increase the amount of cerebral cortex without increasing the overall volume of the brain. Big convolutions are called fissures and small ones sulci. The largest fissure in the brain is the longitudinal fissure. The ridges between fissures are called gyri. The cerebral hemispheres are directly connected by only a few links spanning the longitudinal fissure; these hemisphere connecting links are called cerebral commisures. The largest one is the corpus callosum, which causes the link between the two hemispheres. In some cases of epilepsy, this part of the brain is being cut and this way, the spread of epilepsy is blocked. But when it is cut in a normally functioning brain, it causes split brain, and people have disorientation