Sensory Receptors Flashcards

Sensory Receptors Overview

• Specialized cells detect stimulus information and transmit it to sensory nerves and the brain.
• Sensory receptors carry information towards the Central Nervous System (CNS).

Characteristics of Stimulus Receptors

• All sensory receptors respond to stimuli and are linked with sensory neurons.
• Sensory receptors generate action potentials when stimulated.
• Each receptor typically responds best to a specific type of stimulus.

Types of Sensory Receptors

• Exteroreceptors: Detect external stimuli such as touch, pressure, pain, and temperature.
• Interoreceptors: Monitor internal stimuli including chemical concentrations and temperature changes in internal organs.
• Proprioceptors: Gauge the position and movement of muscles and joints, informing the CNS about body position.
• Mechanoreceptors: Reacts to mechanical changes like pressure, vibration, and stretch.
• Chemoreceptors: Sensitive to chemical changes in the environment.
• Photoreceptors: Respond to light stimuli.
• Nociceptors: Associated with the sensation of pain.

Types of Receptor Structures

• Simple Receptors: General senses with unencapsulated or encapsulated dendritic endings.
• Free Nerve Endings: Dendrites without protective sheaths, found throughout epithelial and connective tissues, serving various sensory roles.
• Encapsulated Nerve Endings: Dendrites enclosed in connective tissue capsules, facilitating pressure and vibration sensing.
• Complex Receptors: Comprised of specialized sense organs like those for vision, hearing, or taste.

Sensory Reception Mechanisms

• Transduction: The conversion of energy from one form to another by sensory receptors.
• Generator Potentials: Depolarizations in simple receptors leading to action potentials.
• Receptor Potentials: Occur in complex receptors involving neurotransmitter release without generating action potentials.

Sensory Signal Processing

• Intensity Coding: Information about stimulus intensity is encoded through changes in action potential frequency.
• Population Coding: Multiple receptors working together provide greater information to the CNS.

Duration and Adaptation of Stimuli

• Duration: Refers to how long a stimulus is perceived.
• Phasic Receptors: Adapt quickly, responding strongly at the beginning and end of a stimulus.
• Tonic Receptors: Slow to adapt; continuously respond as long as a stimulus is present.

Additional Sensory Concepts

• Receptive Field: The specific area monitored by each receptor, often overlapping with other fields.
• Lateral Inhibition: Enhances sensory accuracy by inhibiting nearby receptors when a stimulus is strongly detected in one area.
• Convergence: Multiple neurons synapsing onto a single interneuron, complicating the identification of which neuron sent the signal.

Common Misconceptions

• Not all sensory receptors respond exclusively to one type of stimulus, countering a common misconception.

Test your knowledge on sensory receptors with these flashcards. Learn about specialized cells responsible for detecting stimulus information and their characteristics. Perfect for students studying biology or neuroscience.