The human body has over 220 cell types. One type lies in the brain and nervous system, the neuron. Nerve cells help with cognitive functions and help control automated functions in the body, without them your abilities would be very limited or may cause death. Normally, an adult has about 100 billion of these microscopic specimens. These nerve cells are located down the spine, in the brain, muscles, and glands. There are things that can hurt these neurons and over time cause irreparable damage.
There are three main types of neurons: sensory, interneuron, and motor neurons.
The sensory neurons run to the stimulus receptors where one can smell, see, hear, feel, and taste. The "message" is taken to the central nervous system (CNS), the brain and spinal cord. These are found exclusively within the spinal cord and brain. They are stimulated by signals reaching them from sensory neurons, interneuron, or both.
Interneurons are also called Association Neurons and they hide structural and functional types of cells. Last, motor neurons, they transmit from the CNS to muscles and glands to carry out functions. Most motor neurons are stimulated by interneuron, but some are stimulated by directly by sensory.
Nerve cells carry out a lot of functions, but certain things can also kill them.
Drinking alcohol or smoking marijuana are the most common ways today's society commits 'neurocide'. Brain diseases also cause the abnormal death of these cells. Neurons live the longest of all cells in the body. In Parkinson's disease, neurons that produce the neurotransmitter dopamine die off in the basal ganglia, an area of the brain that controls body movements. The brain can no longer control the body and people shake and jerk in spasms. In Huntington's disease, a genetic mutation causes over-production of a neurotransmitter called...