Show Advanced Search

REFINE YOUR SEARCH:

Containing Text
- - -
+
Filter by author or institution
GO
Filter by publication date
From:
October, 2006
Until:
Today
Filter by journal section

Filter by science education

 
 
Central Nervous System: The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges.

What is a Nervous System?

JoVE 10838

The nervous system is the collection of specialized cells responsible for maintaining an organism’s internal environment and coordinating the interaction of an organism with the external world—from the control of essential functions such as heart rate and breathing to the movement needed to escape danger.

The vertebrate nervous system is divided into two major parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS includes the brain, spinal cord, and retina—the sensory tissue of the visual system. The PNS contains the sensory receptor cells for all of the other sensory systems—such as the touch receptors in the skin—as well as the nerves that carry information between the CNS and the rest of the body. Additionally, part of both the CNS and PNS contribute to the autonomic nervous system (also known as the visceral motor system). The autonomic nervous system controls smooth muscles, cardiac muscles, and glands that govern involuntary actions, such as digestion. The vertebrate brain is primarily divided into the cerebrum, cerebellum, and brainstem. The cerebrum is the largest, most anterior part of the brain that is divided into left and right hemispheres. Each hemisphere is further divided into four lobes: frontal, parietal, occipital, and temporal. The outermost layer of the cerebrum is called

 Core: Biology

The Sympathetic Nervous System

JoVE 10840

The sympathetic nervous system—one of the two major divisions of the autonomic nervous system—is activated in times of stress. It prepares the body to meet the challenges of a demanding circumstance while inhibiting essential body functions—such as digestion—that are a lower priority at the moment.

As a student, you may have had the experience of walking into class and finding a surprise exam that you were not expecting. In the moment of realization, you may sense your gut tighten, your mouth goes dry, and your heart starts to race all of a sudden. These are signs of the sympathetic system taking over in preparation to react. While you may not be in immediate danger, the system has evolved to facilitate immediate reaction to stress or threats: blood is directed away from the digestive system and skin to increase energy supplies to muscles. Furthermore, the heart rate, and blood flow increase, and pupils dilate to maximize visual perception. At the same time, the adrenal gland releases epinephrine into the circulatory system. Your body is now primed to take action, whether that means to swiftly flee from danger or fight whatever threat may be at hand. The sympathetic nervous system can be activated by various parts of the brain, with the hypothalamus playing a particularly important role. Sympathetic instructions from the central

 Core: Biology

In vivo Optogenetic Stimulation of the Rodent Central Nervous System

1Department of Psychiatry, University of Pittsburgh Medical Center, 2Department of Bioengineering, Stanford University, 3Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, 4Department of Neurobiology and Behavior, Cornell University, 5Department of Psychiatry and Behavioral Sciences, Stanford University

JoVE 51483

 Neuroscience
123456789103
More Results...