Central nervous system

The central nervous system or CNS is one of the 2 main parts and is the majority of the nervous system which acts as the processing center. It assimilates the information which comes from and sends it back to the peripheral nervous system.

The brain and spinal cord are the 2 main organs of central nervous system. Enclosed in the skull, the brain and the spinal cord in vertebrae are both protected by 3 layers of meninges, a connective tissue. Some other classifications include retina and cranial nerves as organs of the CNS.

The brain is the hub for processing information and controlling bodily functions. The spinal cord connects the peripheral nervous system or PNS to the brain.

CNS: Brain
The brain weighing about 3 pounds with 100 billion neurons is where reflexes are controlled, pain is processed, and impulses are originated and travelled. This control center of the body has 3 main components: forebrain, brainstem and hindbrain.

Forebrain receives and processes information, thinks, perceives, produces and understands language, which takes place in the cerebral cortex. The thalamus and hypothalamus control motor function and autonomic functions, and relay information.

The midbrain is the part of the brainstem which links the forebrain and the hindbrain. It is responsible for motor function, and auditory and visual responses.

Hindbrain is the region which contains the pons and cerebellum. It helps in maintaining balance and equilibrium, coordinating movement and conducting information. It also contains the medulla oblongata which control autonomic functions (breathing, digestion, and heart rate).

CNS: Spinal Cord
This cylindrical bundle of nerve fibers extends from the neck to lower back inside the protective spinal column. The nerves link information from internal and external stimuli to the brain then send it back to the other parts of the body. Aside from transmitting information or impulses, it is also responsible for initiating some reflexes.

Diseases of the CNS
Infections affecting the central nervous system include encephalitis and poliomyelitis. And some of the diseases which affect CNS are ADHD, autism, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, acute disseminated encephalomyelitis, Krabbe’s disease, Huntington’s disease, and amyotrophic lateral sclerosis.