General Physiology of Senses

A set of vocabulary flashcards covering the morphology, classification, and physiological principles of sensory receptors and perceptual processing.

Sensory Receptors

Specialized epithelial cells or neurons that act as transducers, converting environmental signals into electrochemical impulses.

Free nerve endings

The simplest and most common morphological type of receptors; they detect touch, pressure, stretching, and temperature.

Encapsulated nerve endings

Receptors that are contained within specialized structures, such as Meissner's or Pacinian corpuscles.

Sense organs

Complex structures used for sensing, such as the eyes and ears.

Exteroceptors

Receptors sensitive to stimuli originating from the external environment.

Interoceptors (Visceroceptors)

Receptors that monitor internal body conditions.

Proprioceptors

Receptors that detect body position and movement, such as muscle spindles and Golgi tendon organs.

Mechanoreceptors

Receptors sensitive to mechanical energy, including touch, pressure, and vibration.

Thermoreceptors

Receptors sensitive to temperature changes.

Chemoreceptors

Receptors sensitive to chemical concentrations, such as taste, smell, and blood gases.

Photoreceptors

Receptors sensitive to light or electromagnetic radiation.

Nociceptors

Receptors sensitive to pain resulting from tissue damage.

Adequate Stimulus

The specific form of energy to which a particular receptor is most sensitive.

Receptor Potential

A graded change in membrane potential where the magnitude is proportional to the intensity of the stimulus; it may trigger an $Action Potential$ ($AP$) if it reaches a threshold.

Modality

The type of stimulus determined by the specific "labeled line" or type of receptor activated.

Recruitment

A method of coding stimulus intensity where stronger stimuli affect a larger area, activating a greater number of receptors.

Receptive field

The specific area of the body that, when stimulated, leads to activity in a particular neuron.

Adaptation

A change in sensitivity over time when a stimulus is constant, occurring in all senses except pain.

Tonic Receptors (Slow-adapting)

Receptors that respond for the entire duration of a stimulus, such as Merkel's discs for continuous pressure.

Phasic Receptors (Rapid-adapting)

Receptors that fire only at the beginning (and sometimes end) of a stimulus and "turn off" if the stimulus remains constant, such as Meissner's corpuscles.

Lateral Inhibition

A mechanism that increases contrast and sharpens perception by allowing the pathway closest to the center of a stimulus to inhibit neighboring neurons at the border.

Association Cortices

Higher-order unimodal and multimodal areas where perceptual processing and the integration of signals from multiple brain parts occur.

Phantom limb syndrome

A biological fault where damaged neural networks lead to faulty perceptions of a limb that is no longer there.