noun, plural: sensory neurons
The neurons are regarded as the functional unit of the nervous system. Their main function is to transmit nerve impulses. Unlike other cells, the neurons are identifiable by their processes such as dendrites and axons. The dendrites are the processes that receive (sensory) input. The axon has specialized endings that are called synaptic terminals. Neurotransmitters are released from the synaptic terminals to reach the target cell, which may be another neuron, a muscle fiber, or a secretory cell. Sensory neurons are one of the three main types of neurons. The others are the motor neurons and the interneurons. Sensory neurons are the ones that transmit sensory input to the central nervous system for integration. Because of the direction of the nerve impulse transmission, the sensory neurons are afferent neurons. The sensory information that they relay is about the external and internal stimuli detected by the sense organs (e.g. sight, sound, taste, pain, smell, touch, pressure, vibration, limb position, heat, cold, etc.). Most of the sensory neurons communicate with interneurons inside the central nervous system for integration.