Brief Look at the Nervous System

In order to understand the therapeutic effects of medication used to treat the nervous system, you'll need to have an understanding of the anatomy and phys

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iology of the system. The nervous system is comprised of the brain, spinal cord, nerves, and ganglia. Collectively, they receive stimuli and transmit information.

There are two nervous systems. These are the central nervous system (CNS) and the peripheral nervous system (PNS). The central nervous system consists of the brain and spinal cord, which are responsible for regulating body function. The central nervous system receives information from the peripheral nervous system, which is interpreted, and then the central nervous system sends an appropriate signal to the peripheral nervous system to stimulate cellular activity. Depending on the signal, the stimulation either increases or blocks nerve cells, which are called neurons.

The peripheral nervous system is organized into two divisions. These are the somatic nervous system (SNS) and the autonomic nervous system (ANS). The somatic nervous system acts on skeletal muscles to produce voluntary movement. The autonomic nervous system, known as the visceral system, is responsible for involuntary movement and controls the heart, respiratory system, gastrointestinal system, and the endocrine system (glands).

The autonomic nervous system is further divided into the sympathetic and parasympathetic nervous systems (see Autonomic Nervous System).

The sympathetic nervous system is called the adrenergic system and uses the norephinephrine neurotransmitter to send information. The parasympathetic system, called the cholinergic system, uses the acetylcholine neurotransmitter to transmit information.

Both the sympathetic and parasympathetic nervous systems innervate organs within the body. The sympathetic system excites the organ while the parasympathetic system inhibits the organ. For example, the sympathetic system increases the heart rate while the parasympathetic system decreases the heart rate.

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