Receptor Potential

Definition

Receptor potential is a change in the membrane potential of a sensory receptor cell in response to a stimulus, which is crucial for converting external signals into neural signals. This local electrical change is proportional to the intensity of the stimulus and plays a fundamental role in sensory transduction, enabling the nervous system to interpret and respond to various environmental cues.

5 Must Know Facts For Your Next Test

1. Receptor potentials are graded responses, meaning they vary in magnitude based on the strength of the stimulus.
2. These potentials are typically localized and can lead to action potentials if they reach a certain threshold.
3. Different types of sensory receptors (like photoreceptors, mechanoreceptors, and thermoreceptors) produce receptor potentials specific to their modalities.
4. Receptor potentials are crucial for sensory adaptation, allowing organisms to adjust their sensitivity to constant stimuli over time.
5. Inadequate receptor potentials can lead to diminished sensory perception or impaired ability to respond to environmental changes.

Review Questions

• How do receptor potentials contribute to the process of sensory transduction?
  • Receptor potentials play a vital role in sensory transduction by converting physical stimuli, such as light or sound waves, into electrical signals. When a sensory receptor cell detects a stimulus, it generates a receptor potential that alters its membrane potential. If this potential is strong enough, it can trigger an action potential that travels along sensory neurons to the brain, ultimately allowing for perception and response to the environment.
• Compare and contrast receptor potentials with action potentials regarding their characteristics and functions within the nervous system.
  • Receptor potentials are localized changes in membrane potential that occur in sensory receptor cells and are graded based on stimulus intensity. In contrast, action potentials are all-or-nothing events that occur along axons and have a uniform amplitude. While receptor potentials can vary and may or may not result in an action potential depending on whether the threshold is met, action potentials are responsible for transmitting information over long distances within the nervous system.
• Evaluate the implications of receptor potential sensitivity in relation to sensory adaptation and its importance for survival.
  • The sensitivity of receptor potentials is crucial for sensory adaptation, which allows organisms to become less responsive to constant or unchanging stimuli over time. This ability to adapt helps prevent overload from irrelevant information and ensures that only significant changes in the environment are processed. For survival, this means that organisms can quickly react to important signals, like predators or food sources, without being distracted by non-essential stimuli. Thus, efficient receptor potential sensitivity enhances an organism's ability to navigate and survive in its environment.

Related terms

Sensory Transduction: The process by which sensory receptors convert external stimuli into electrical signals that can be processed by the nervous system.

Action Potential:

A rapid, temporary change in membrane potential that travels along neurons, allowing for the transmission of information throughout the nervous system.

Threshold:

The minimum level of stimulus intensity required to trigger an action potential in a sensory neuron after the receptor potential has occurred.