Sensory neurons

Definition

Sensory neurons are specialized nerve cells responsible for converting external stimuli into electrical signals that the nervous system can interpret. They play a critical role in transmitting sensory information from sensory receptors, like those for touch, sight, sound, taste, and smell, to the central nervous system for processing and response.

5 Must Know Facts For Your Next Test

1. Sensory neurons can be categorized based on the type of sensation they transmit, including mechanoreceptors for touch, photoreceptors for light, and chemoreceptors for taste and smell.
2. The cell body of sensory neurons typically resides in ganglia located outside the central nervous system, while their axons project into the central nervous system.
3. Sensory neurons can adapt to constant stimuli; for example, if you wear a watch all day, your sensory neurons may become less responsive to the sensation of the watch against your skin.
4. Injuries to sensory neurons can lead to loss of sensation or altered perception of stimuli, highlighting their importance in everyday experiences.
5. The signals generated by sensory neurons are crucial for reflex actions, where an immediate response occurs before the information is processed by the brain.

Review Questions

• How do sensory neurons contribute to the process of sensory transduction?
  • Sensory neurons are essential for sensory transduction as they convert various forms of external stimuli into electrical signals. This process begins when sensory receptors detect changes in the environment—like light or sound—and trigger action potentials in sensory neurons. These electrical signals then travel along the sensory neurons toward the central nervous system where they are interpreted, allowing us to perceive our surroundings.
• Discuss the differences between sensory neurons and motor neurons in terms of their functions and pathways.
  • Sensory neurons and motor neurons serve distinct functions in the nervous system. Sensory neurons are responsible for transmitting information from sensory receptors to the central nervous system, while motor neurons carry commands from the central nervous system to muscles or glands. Sensory neurons typically have their cell bodies located in peripheral ganglia, whereas motor neuron cell bodies are located within the central nervous system. This separation illustrates their different roles in processing information and generating responses.
• Evaluate how damage to sensory neurons can affect overall body function and perception.
  • Damage to sensory neurons can lead to significant disruptions in how the body perceives and interacts with its environment. For instance, injury or disease affecting these neurons can result in loss of sensation (such as numbness) or altered perceptions (like pain or tingling), which impact daily activities. Additionally, this loss can interfere with reflex actions that protect the body from harm. Understanding these consequences highlights the critical role sensory neurons play in maintaining not just perception but overall bodily function.

Related terms

afferent neurons: Afferent neurons are another name for sensory neurons, emphasizing their function of carrying information toward the central nervous system.

receptors: Receptors are specialized structures that detect specific types of stimuli, such as light, sound, or chemical changes, and initiate the sensory transduction process.

neural pathways: Neural pathways are the routes taken by sensory neurons and other types of neurons to transmit information throughout the nervous system.