Outline the role of sensory receptor cells in detecting stimuli and stimulating the transmission of impulses in sensory neurones

Sensory receptor cells are specialized structures that detect specific environmental stimuli and convert them into electrical signals, initiating the transmission of impulses through sensory neurons to the central nervous system (CNS).

Role of Sensory Receptor Cells:

1. Detection of Stimuli: Each sensory receptor cell is tuned to a particular type of stimulus, such as light, sound, temperature, or chemical changes. For example, photoreceptor cells in the retina detect light, while mechanoreceptor cells in the skin respond to pressure and vibration. LibreTexts
2. Transduction of Stimuli: Upon detecting a stimulus, sensory receptor cells undergo a process called transduction, where the physical or chemical energy of the stimulus is converted into an electrical signal. This involves changes in the cell’s membrane potential, leading to the generation of a receptor potential. University of Washington Pressbooks
3. Generation of Action Potentials: If the receptor potential reaches a certain threshold, it triggers an action potential in the associated sensory neuron. This electrical impulse travels along the neuron’s axon toward the CNS, conveying information about the stimulus. Wikipedia
4. Transmission to the CNS: The action potential reaches the axon terminals of the sensory neuron, where neurotransmitters are released into synapses with interneurons or directly with neurons in the CNS. This facilitates the processing and interpretation of sensory information, leading to perception and appropriate responses.