The nervous system is those parts of an organism responsible for conveying motor information from the brain to rest of te body, and for conveying sensory information from the body to the brain. It is composed of highly specialized cells called neurons, and of cells that support and nourish these cells. The chief organ of the nervous system is the brain.
Structure of the Nervous System
The central nervous system consists of the brain and the spinal cord; it is rich in neurons and supporting glial cells. The voluntary nervous system consists of those parts of the nervous system, including parts of the brain and spinal cord, that are responsible for movement of the voluntary muscles; that is, all those muscles normally under conscious control. The sympathetic and parasympathetic nervous system consists of those parts that regulate the autonomic functions of the body: breathing, heart rate, digestion, and so forth -- anything not normally under conscious control. The sympathetic and parasympathetic nervous systems act in an excitatoty and inhibitory fashion, respectively, implementing (along with the brain) a feedback driven control system.
Diseases of the Nervous System
Diseases of the nervous system fall into two broad categories, genetic and infectious. Genetic disorders arise from a flaw in the individual's genetic code. Infectious disorders arise from an external pathogen, such as a virus or bacterium, that invades the cells of the nervous system in large numbers. These infectious agents kill the cells, or interfere with their function to so great a degree that they cannot fill their roles in the nervous system.
Disorders of the nervous system
- Anterograde amnesia
- Bendii Syndrome
- Clarke's Disease
- Forrester-Trent Syndrome
- Memory virus
- Pa'nar Syndrome
- Transporter psychosis
- Tuvan Syndrome
- Vegan choriomeningitis
Parasites of the Nervous System
- Ceti eel
- Neural parasites