The back portion of this butterfly shape is known as the posterior, sometimes called the dorsal gray horn. This region passes sensory information via ascending nerve signals to the brain. The front part, which is sometimes called the ventral gray horn, sends descending nerve signals governing motor activities to your autonomic nerves. A problem with the dorsal gray horn may affect your brain's ability to interpret sensory information, while issues with the ventral gray horn interfere with your body's ability to receive motor information; paralysis, tingling, and muscle weakness are often the products of damage to the ventral gray horn.
The white matter of your brain and spinal cord is composed of bundles of axons. These axons are coated with myelin, a mixture of proteins and lipids, that helps conduct nerve signals and protect the axons. White matter's job is to conduct, process, and send nerve signals up and down the spinal cord. Damage to the white matter of your brain or spinal cord can affect your ability to move, use your sensory faculties, or react appropriately to external stimuli.
Some people with damaged white matter suffer deficits in reflexive reactions. Together, the gray and white matter of your brain and spinal cord help form spinal tracts. These pathways send nerve signals from your brain to the rest of your body.
Knowing the most common tracts can help you discern the source of your injury. Figure 1: Reconstructed white matter fiber tracts of the brain, brainstem, and spinal cord. View through the mid-sagittal plane. Rendering is work of Thomas Schultz, using a modified version of the BioTensor application developed at the University of Utah.
Brain tissue is composed primarily of neurons and glia. Neurons are cells that transmit information throughout the body. As described in Neuron a Superhighway! Glial cells, on the other hand, are broadly defined as non-neuronal cells that maintain the local environment.
Stephanie Pappas is a contributing writer for Live Science covering topics from geoscience to archaeology to the human brain and behavior. A freelancer based in Denver, Colorado, she also regularly contributes to Scientific American and The Monitor, the monthly magazine of the American Psychological Association. Stephanie received a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz.
Live Science. Printer-Friendly Version. Cerebellum At the rear of the brain is the cerebellum. The cerebellum is similar to the cerebrum in that each has hemispheres that control the opposite side of the body and are covered by gray matter and surface folds. The vermis, which is a central constricted area, connects the hemispheres. The cerebellum is concerned with the automatic regulation of movement and posture, and the learning of new motor patterns.
The cerebellum basically coordinates body movement and is located at the back of the brain beneath the occipital lobes. The cerebellum fine tunes motor activity or movement such as the fine movements of fingers. The cerebellum controls balance or equilibrium, posture, and coordination by controlling the tone of muscles and the position of limbs. The cerebellum is important in one's ability to perform rapid and repetitive actions such as playing a video game.
In the cerebellum, right-sided abnormalities produce symptoms on the same side of the body.
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