Final answer:
Sensory receptors are specialized cells or cell processes, including neurons with free or encapsulated nerve endings, which detect environmental stimuli and translate them into electrical signals within the nervous system. These structures play a crucial role in sensory transduction, which involves the activation of sensory receptors by stimuli and the subsequent processing of this information by the central nervous system.
Step-by-step explanation:
Messages from other neurons or specialized cells and sensory receptors are typically involved in the process of sensory transduction. Sensory transduction can be performed by two broad types of cellular systems. One involves a neuron that works along with a sensory receptor, which is a specialized cell or cell process designed to detect specific stimuli. The stimulation of the sensory receptor activates the associated afferent neuron, sending information to the central nervous system. In the second type, a sensory nerve ending itself acts as the sensory receptor responding to stimuli in the internal or external environment.
Structurally, sensory receptor types can be classified as neurons with free nerve endings, neurons with encapsulated endings, or as specialized receptor cells. For instance, photoreceptors in the eyes, such as rod cells, are examples of specialized receptor cells that release neurotransmitters to bipolar cells that subsequently synapse with optic nerve neurons. Information from these receptors is ultimately processed by the brain, leading to perception.
The function of the sensory system is to convert sensory signals, received by the sensory receptors, into electrical signals within the nervous system. This conversion is known as transduction. The sensory receptors have distinct receptive fields within which they can detect stimuli. The fundamental function of this sensory system is to translate these various sensory signals to electrical signals that the nervous system can interpret.