Summary
Mechanoreceptors, thermoreceptors, chemoreceptors and photoreceptors transduce stimuli into signals.
In depth
Adaptation: phasic receptors respond to change (smell, touch pressure) while tonic receptors give sustained signals (pain). Receptive fields are smaller in sensitive areas. Transduction creates generator potentials.
Receptors respond to specific stimuli. Intensity is coded by firing rate. Receptive field size determines acuity.
Key idea: transduction converts a stimulus to an electrical signal.
Receptor types: mechanoreceptors (Meissner's corpuscles, Pacinian corpuscles for vibration, Merkel discs, Ruffini endings, hair cells), thermoreceptors (TRPV1 for heat, TRPM8 for cold, which also respond to capsaicin and menthol, awarded the 2021 Nobel Prize to Julius and Patapoutian along with PIEZO channels), nociceptors, chemoreceptors, photoreceptors, and electroreceptors in some animals. Receptive fields and lateral inhibition sharpen perception: fingertips have small fields and high acuity, and the back has large ones (two-point discrimination).
Stimulus intensity is coded by frequency and by the number of receptors recruited (Weber-Fechner law, Stevens's power law). Labelled-line coding means that activating a pain fibre produces pain regardless of how it is stimulated. Phantom limbs show that perception is built centrally.
Remember: receptors transduce energy into graded receptor potentials that lead to action potentials.
Frequently asked questions
What is Sensory Receptors?
Mechanoreceptors, thermoreceptors, chemoreceptors and photoreceptors transduce stimuli into signals.
Which area of biology covers Sensory Receptors, and how advanced is it?
Sensory Receptors is one of the 54 topics in Neuroscience. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Taste and Smell, Action Potential, Eye and Vision.
Can you give an example of Sensory Receptors?
You stop noticing clothes against skin because of adaptation.
What should I learn before Sensory Receptors?
Work through the Beginner topics in Neuroscience first, such as Nervous System, Neuron, Central and Peripheral Nervous Systems, then return to Sensory Receptors. Intermediate topics assume the Beginner vocabulary.
What topics are related to Sensory Receptors?
The closest topics to Sensory Receptors are Taste and Smell, Action Potential, Eye and Vision, Visual Cortex Processing. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Sensory Receptors?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Sensory Receptors. To practise the whole of Neuroscience, use the Neuroscience quiz.
How is Sensory Receptors different from Taste and Smell?
Sensory Receptors: Mechanoreceptors, thermoreceptors, chemoreceptors and photoreceptors transduce stimuli into signals. Taste and Smell: Chemoreceptors in taste buds and olfactory epithelium detect dissolved and airborne molecules. Read both side by side and note what each one explains.
How should I study Sensory Receptors step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Taste and Smell and explain the difference aloud. Finally, take the Neuroscience quiz and come back to this page for any question you miss.