Sensory receptor

Definition

A sensory receptor is a specialized cell or structure that detects and responds to specific types of stimuli from the environment, converting these stimuli into electrical signals that can be interpreted by the nervous system. These receptors play a vital role in sensory perception, allowing organisms to respond to changes in their surroundings, and are crucial for reflexes and central pattern generators.

5 Must Know Facts For Your Next Test

1. Sensory receptors are classified into different types based on the kind of stimulus they respond to, including photoreceptors for light, mechanoreceptors for touch and pressure, chemoreceptors for chemicals, and thermoreceptors for temperature.
2. Each sensory receptor is specifically adapted to detect certain stimuli, and the response can vary based on the intensity and duration of the stimulus.
3. Sensory receptors can be found throughout the body, including in the skin, eyes, ears, nose, and mouth, each contributing to our overall perception of the environment.
4. When sensory receptors detect a stimulus, they initiate a reflex arc by sending signals through afferent neurons to the spinal cord or brain, leading to rapid responses.
5. Central pattern generators are neural circuits that can produce rhythmic outputs and are influenced by input from sensory receptors, coordinating movements without needing direct sensory input for each action.

Review Questions

• How do sensory receptors contribute to the process of reflexes in the nervous system?
  • Sensory receptors are essential for initiating reflexes by detecting stimuli such as heat or pain. When a sensory receptor is activated by a stimulus, it sends a signal through afferent neurons to the spinal cord. This signal triggers an immediate response via motor neurons, resulting in an involuntary action without needing conscious thought, effectively protecting the body from harm.
• Discuss the role of transduction in sensory receptors and how it relates to central pattern generators.
  • Transduction is the process through which sensory receptors convert external stimuli into electrical signals that the nervous system can understand. This process is crucial for both sensory perception and for central pattern generators, which rely on sensory feedback to maintain rhythmic movements. When sensory information is transduced, it informs central pattern generators about environmental conditions, allowing for coordinated actions such as walking or swimming.
• Evaluate how the specific adaptations of different types of sensory receptors affect their sensitivity and response time during reflex actions.
  • Different types of sensory receptors have unique adaptations that influence their sensitivity and response time during reflex actions. For instance, photoreceptors in the eyes are highly sensitive to light changes and react quickly to visual stimuli, while mechanoreceptors in the skin respond to touch or pressure with varying thresholds. These adaptations ensure that reflex actions occur rapidly and effectively based on the nature of the stimulus. The efficiency of these receptors directly impacts how well an organism can respond to environmental changes, illustrating their crucial role in survival.

Related terms

afferent neurons: Nerve cells that carry sensory information from sensory receptors to the central nervous system.

transduction: The process by which sensory receptors convert external stimuli into electrical signals for the nervous system.

motor neurons:

Nerve cells that transmit signals from the central nervous system to muscles or glands, enabling responses to sensory input.