In my 2-Minute Neuroscience videos I explain neuroscience topics in 2 minutes or less. In this video, I discuss the divisions of the nervous system. The nervous system has two major divisions: central and peripheral. But the peripheral nervous system is further subdivided into the somatic and autonomic nervous system, and the autonomic nervous system is also divided into sympathetic and parasympathetic fibers. All of these are discussed in this 2-minute video.
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TRANSCRIPT:
Welcome to 2 minute neuroscience, where I simplistically explain neuroscience topics in 2 minutes or less. In this installment I will discuss the divisions of the nervous system.
There are two major divisions of the nervous system. The first is the central nervous system, which is made up of the brain and the spinal cord. The second is the peripheral nervous system, which consists of nerves that run throughout the boy.
The peripheral nervous system itself is made up of two subdivisions. The first is the somatic nervous system, which contains nerves that carry sensory signals from the body to the central nervous system and nerves that carry motor signals from the central nervous system to skeletal muscles. The somatic nervous system is thus associated with voluntary movement. When you clicked on this video to play it, the signal to depress your finger was sent via the somatic nervous system.
The second division of the peripheral nervous system is the autonomic nervous system. The autonomic nervous system is sometimes called the involuntary nervous system, and it is involved in regulating the internal environment of the body. It carries signals from internal organs to the central nervous system and from the central nervous system to the internal organs. In this way, it is involved in regulating things like digestion and heartbeat, which are generally outside the realm of conscious control.
The autonomic nervous system can be further subdivided into sympathetic and parasympathetic nerve fibers. The sympathetic nervous system plays a larger role in stimulating and mobilizing energy resources, while the parasympathetic nervous system acts to conserve energy. For example, if you are in a frightening situation, the sympathetic nervous system will cause your heart rate to increase, your blood pressure to increase, and your sweat glands to be stimulated. If you are eating a meal, however, and are not frightened, your parasympathetic nervous system will become activated to stimulate digestion, increase salivation, and slow your heart rate.
Due to its role in mobilizing energy in threatening situations, the sympathetic nervous system is often described as being involved in fight or flight responses, while the parasympathetic nervous system is described as being involved in rest and digest responses.
REFERENCE:
Purves D, Augustine GJ, Fitzpatrick D, Hall WC, Lamantia AS, McNamara JO, White LE. Neuroscience. 4th ed. Sunderland, MA. Sinauer Associates; 2008.