Receptor potential

Definition

Receptor potential is a change in the membrane potential of a sensory receptor cell in response to a stimulus, leading to the generation of an electrical signal. This graded potential is crucial for converting various types of physical energy, such as light, sound, or pressure, into neural signals that can be processed by the nervous system. The magnitude of the receptor potential is directly related to the intensity of the stimulus, and it plays a key role in initiating sensory pathways.

5 Must Know Facts For Your Next Test

1. Receptor potentials are typically localized changes in membrane potential and can vary in size depending on the strength of the stimulus.
2. Unlike action potentials, receptor potentials are graded; this means their amplitude can increase with stronger stimuli.
3. In sensory neurons, if the receptor potential is large enough to reach the threshold, it triggers an action potential that propagates along the nerve fibers.
4. Different types of sensory receptors (photoreceptors, mechanoreceptors, etc.) produce specific receptor potentials tailored to their respective stimuli.
5. Receptor potentials can undergo adaptation, meaning that over time, prolonged exposure to a constant stimulus can reduce their amplitude.

Review Questions

• How does receptor potential contribute to sensory perception and processing?
  • Receptor potential is essential for sensory perception as it converts external stimuli into electrical signals that can be transmitted to the brain. When a sensory receptor is activated by a stimulus, it generates a receptor potential that changes its membrane potential. If this change is significant enough, it will trigger an action potential that travels along sensory neurons to the central nervous system, allowing for the interpretation and response to the sensory information.
• Discuss the differences between receptor potentials and action potentials in terms of their characteristics and roles in sensory pathways.
  • Receptor potentials are graded responses that vary in size depending on stimulus intensity, while action potentials are all-or-nothing signals that do not vary in size but rather occur once a threshold is reached. Receptor potentials initiate the process of sensory transduction by transforming physical stimuli into electrical signals, which then lead to action potentials when they reach sufficient magnitude. The differences in these potentials are crucial for accurately encoding sensory information and ensuring effective communication within sensory pathways.
• Evaluate how receptor potential adaptation impacts sensory experience and responsiveness over time.
  • Receptor potential adaptation allows sensory receptors to adjust their sensitivity based on prolonged exposure to a constant stimulus. This phenomenon helps prevent overload and enables organisms to remain responsive to changes in their environment rather than being distracted by unchanging stimuli. For instance, when someone enters a room with a strong odor, they may initially notice it due to high receptor potential but may become less aware of it over time as the receptors adapt. This dynamic adjustment plays a significant role in how we perceive our surroundings and react to new stimuli.

Related terms

Action potential: A rapid, all-or-nothing electrical signal that travels along the axon of a neuron, triggered when the receptor potential reaches a certain threshold.

Sensory transduction: The process by which sensory receptors convert physical stimuli into electrical signals that can be interpreted by the nervous system.

Graded potential: A change in membrane potential that varies in magnitude and can lead to action potentials if sufficiently strong, including receptor potentials.