neuron cell bodies found in clusters in the cns are called
Nucleus (neuroanatomy) In neuroanatomy, a nucleus (plural form: nuclei) is a cluster of neurons in the central nervous system,[1] located deep within the cerebral hemispheres and brainstem.[2] The neurons in one nucleus usually have roughly similar connections and functions.[3] Nuclei are connected to other nuclei by tracts, the bundles (fascicles) of axons (nerve fibers) extending from the cell bodies. A nucleus is one of the two most common forms of nerve cell organization, the other being layered structures such as the cerebral cortex or cerebellar cortex. In anatomical sections, a nucleus shows up as a region of gray matter, often bordered by white matter. The vertebrate brain contains hundreds of distinguishable nuclei, varying widely in shape and size. A nucleus may itself have a complex internal structure, with multiple types of neurons arranged in clumps (subnuclei) or layers.
Motor neuron A motor neuron (or motoneuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly control effector organs, mainly muscles and glands.[1] There are two types of motor neuron â€“ upper motor neurons and lower motor neurons. Axons from upper motor neurons synapse onto interneurons in the spinal cord and occasionally directly onto lower motor neurons.[2] The axons from the lower motor neurons are efferent nerve fibers that carry signals from the spinal cord to the effectors.[3] Types of lower motor neurons are alpha motor neurons, beta motor neurons, and gamma motor neurons.