NationMaster - Encyclopedia: Central Nervous System

Meissner's corpuscle - Merkel nerve ending - Pacinian corpuscle - Ruffini ending - Muscle spindle

Free nerve ending As a part of the retina, the bipolar cell exists between photoreceptors (rod cells and cone cells) and ganglion cells. ... Pseudounipolar cells (Pseudo- false, uni- one) are sensory neurons in the peripheral nervous system. ... The multipolar neuron possesses a single (usually long) axon and many dendrites, allowing for the integration of a great deal of information from other neurons. ... A pyramidal cell (or pyramidal neuron, or projection neuron) is a multipolar neuron located in the hippocampus and cerebral cortex. ... Drawing of pigeon Purkinje cells (A) by Santiago Ramon y Cajal Purkinje cells are a class of GABAergic neuron located in the cerebellar cortex. ... In neuroscience, granule cells are tiny cells found within the granular layer of the cerebellum. ... The mechanism of the reflex arc In the nervous system, afferent neurons--otherwise known as sensory or receptor neurons--carry nerve impulses from receptors or sense organs toward the central nervous system. ... The mechanism of the reflex arc Sensory neurons (or neurones) are nerve cells within the nervous system responsible for converting external stimuli from the organisms environment into internal electrical impulses. ... The mechanism of the reflex arc Sensory neurons (neurones) are nerve cells within the nervous system responsible for converting external stimuli from the organisms environment into internal electrical motor reflex loops and several forms of involuntary behavior, including pain avoidance. ... The general somatic afferent fibers (or somatic sensory fibers), afferent fibers, arise from cells in the spinal ganglia and are found in all the spinal nerves, except occasionally the first cervical, and conduct impulses of pain, touch and temperature from the surface of the body through the posterior roots to... The general visceral afferent fibers (GVA, or sympathetic afferent fibers), conduct sensory impulses from the viscera through the rami communicantes and posterior roots to the spinal cord. ... Special somatic afferent (SSA) refers to efferent nerves which supply muscles derived from ectoderm. ... Special visceral afferent (SVA) refers to afferent nerves supporting the gastrointestinal tract. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... Type Ia Sensory Fiber also called Primary Afferent Type 1A Fiber or Group II sensory fibers is a component of a muscle fibers muscle spindle which keeps track of the how fast a muscle stretch changes (the velocity of the stretch). ... Organ of Golgi (neurotendinous spindle) from the human tendo calcaneus. ... Type II sensory fiber are the second of the two main groups of stretch receptors. ... A delta fibers (AÎ´) are the fibers which convey fast pain information. ... C-fibers are unmyeliniated and as a result, have a slower conduction velocity, lower than 2 m/s. ... In the nervous system, efferent nerves otherwise known as motor or effector neuron carry nerve impulses away from the central nervous systemto effectors - either muscles or glands. ... Motor nerves allow the brain to stimulate muscle contraction. ... In vertebrates, the term motor neuron (or motoneuron) classically applies to neurons located in the central nervous system (CNS) which project their axons outside the CNS and directly or indirectly control muscles. ... The general somatic efferent fibers (or somatic motor fibers), efferent fibers, arise from cells in the anterior column of the spinal cord and pass out through the anterior roots to the voluntary muscles. ... The general visceral efferent fibers (GVE or sympathetic efferent fibers), probably arise from cells in the lateral column or the base of the anterior column and emerge through the anterior roots and white rami communicantes. ... Special visceral efferent (SVE) refers to efferent nerves which supply muscles which derived from the branchial arches. ... Upper motor neurons are any neurons that carry motor information down to the final common pathway, that is, any neurons that are not directly responsible for stimulating the target muscle. ... Lower motor neurons (LMNs) are the motor neurons connecting the brainstem and spinal cord to muscle fibers, bringing the nerve impulses from the upper motor neurons out to the muscles. ... Alpha motor neurons (Î±-MNs) are large lower motor neurons of the brainstem and spinal cord. ... A muscle spindle, with Î³ motor and Ia sensory fibers Gamma motoneurons (Î³-motoneurons), also called gamma motor neurons, are a component of the fusimotor system, the system by which the central nervous system controls muscle spindle sensitivity. ... Illustration of the major elements in a prototypical synapse. ... Neuropil is the feltwork of unmyelinated neuronal processes (axonal and dendritic) within the gray matter of the central nervous system Traditionally, when pathologists looked at brain tissue they concentrated on neurons (the active functioning cells of the brain), glial cells and axons (especially in white matter, which is mostly composed... In a neuron, synaptic vesicles, also called neurotransmitter vesicles, store the various neurotransmitters that are released during calcium-regulated exocytosis at the presynaptic terminal into the synaptic cleft of a synapse. ... A neuromuscular junction is the junction of the axon terminal of a motoneuron with the motor end plate, the highly-excitable region of muscle fiber plasma membrane responsible for initiation of action potentials across the muscles surface. ... An electrical synapse is a mechanical and electrically conductive link between two abutting neurons that is formed at a narrow gap between the pre- and postsynaptic cells known as a gap junction. ... An interneuron (also called association neuron or bipolar neuron) is a sensory neuron in neural pathways like the motor neurons their bodies cells are always located in the CNS. // According to the PNS definition, the neurons of the central nervous system, including the brain, are all interneurons. ... Renshaw cells are located in the spinal cord horn. ... In a sensory system, a sensory receptor is a structure that recognizes a stimulus in the internal or external environment of an organism. ... Meissners corpuscles (discovered by the anatomist Georg Meissner (1829-1903) are a type of mechanoreceptor and more specifically, a tactile corpuscle(corpusculum tactus). ... Merkel nerve endings are mechanoreceptors found in the skin and mucosa of vertebrates that provide touch information to the brain. ... A Pacinian corpuscle is a structure that functions as a mechanoreceptor. ... Ruffini Endings are one of the four main cutaneous mechanoreceptors. ... A muscle spindle is a specialized muscle structure innervated by both sensory and motor neuron axons. ... NERVE ENDINGS SUCK PENIS!!! ...

Olfactory receptor neuron - Photoreceptor cell - Hair cell - Taste bud

Contents

3 Parts

Function

Neuroanatomy

Evolution

Parts of the vertebrate CNS

See also

References

External links