Sensory nerve
From The Art and Popular Culture Encyclopedia
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Sensory nerves are nerves that receive sensory stimuli, such as how something feels and if it is painful, smooth, rough, etc.
They are made up of nerve fibers, called sensory fibers (mechanoreceptor fibers sense body movement and pressure placed against the body, and nociceptor fibers sense tissue injury).
Sensory neurons are neurons that are activated by sensory input (vision, touch, hearing, etc.), and send projections into the central nervous system that convey sensory information to the brain or spinal cord. Unlike neurons of the central nervous system, whose inputs come from other neurons, sensory neurons are activated by physical modalities such as light, sound, temperature, chemical stimulation, etc.
In complex organisms,the central nervous system is the destination in which sensory neurons transmit their data to; in the case of less complex organisms, such as the hydra, sensory neurons send their data to motor neurons and sensory neurons can also send data via (electrical impulses) to the brain.
At the molecular level, sensory receptors located on the cell membrane of sensory neurons are responsible for the conversion of stimuli into electrical impulses. The type of receptor employed by a given sensory neuron determines the type of stimulus it will be sensitive to. For example, neurons containing mechanoreceptors are sensitive to tactile stimuli, while olfactory receptors make a cell sensitive to odors.
Fiber types
Peripheral nerve fibers can be classified based on axonal conduction velocity, mylenation, fiber size etc. For example, there are slow-conducting unmyelinated C fibers and faster-conducting myelinated Aδ fibers.
Types
There are several types of sensory nerve fibers, depending on their modality etc. Examples are:
See also
