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Sensory Processing

The process by which the nervous system receives and interprets information from the sensory organs about the external environment.

Sensory Systems

Systems in the body that receive and process sensory information from the surroundings, primarily through six senses: vision, hearing, taste, smell, touch, and balance.

Sensory Transduction

The conversion of physical energy from the environment into changes in membrane potential in sensory receptor cells.

Sensory Receptor Organs

Specialized organs that receive specific stimuli from the environment and begin the process of sensory transduction.

Membrane Potential

The difference in electrical charge across a cell's plasma membrane that can change in response to stimuli.

Bipolar Neurons

Type of neuron with two extensions; involved in the olfactory system and retina.

Unipolar Neurons

Neurons with one process that splits into two; relevant in sensory pathways for touch and pain.

Generator Potentials

Changes in membrane potential that can lead to action potentials in sensory receptors.

Thresholds

The minimum intensity of stimuli required for detection; includes absolute threshold and adequate stimulus.

Receptive Field

The specific area where a sensory receptor can detect stimulus; affects the neuron's activity.

Labeled Lines

The concept that specific pathways in the nervous system correspond to particular sensory modalities.

Somatosensory Pathways

Paths that somatosensory information follows to the brain, involving multiple synapses and processing locations.

Action Potential

A rapid rise and fall in membrane potential that propagates signals along a neuron.

TRP Channels

Transient Receptor Potential channels that act as sensors in various sensory systems.

Adequate Stimulus

The type of stimulus for which a sensory receptor is specifically adapted.

Absolute Threshold

The lowest level of a stimulus that can be detected 50% of the time.

Tonic Receptors

Slowly adapting receptors that respond continuously to a persistent stimulus.

Phasic Receptors

Rapidly adapting receptors that respond to changes in stimulus intensity.

Spatial Coding

The process by which the brain determines the location of a stimulus based on neural activity.

Lateral Inhibition

A neural mechanism in which excited neurons inhibit the activity of neighboring neurons, enhancing contrast in sensory perception.

Sensory Adaptation

The process by which sensory receptors decrease their sensitivity to a constant stimulus over time.

Fine Touch

A tactile sensation that involves the ability to detect small details and texture.

Proprioception

The body's ability to sense its position, motion, and equilibrium.

Nociceptors

Sensory receptors that respond to potentially damaging stimuli, leading to the perception of pain.

Somatosensory Cortex

The part of the brain that processes sensory information from the body, especially regarding touch.

Olfactory System

The sensory system responsible for the sense of smell.

Gustatory System

The sensory system responsible for the sense of taste.

Auditory System

The sensory system responsible for the sense of hearing.

Vestibular System

The sensory system that helps maintain balance and spatial orientation.

Neural Energy

The electrical signals generated by neurons, allowing communication throughout the nervous system.

Peripheral Process

The part of a sensory receptor that extends into the peripheral nervous system.

Central Process

The part of a sensory receptor that extends into the central nervous system.

Cutaneous Senses

Sensations of touch, pressure, pain, temperature, and vibration detected by the skin.

Chemical Senses

Senses that respond to chemical stimuli, including taste (gustation) and smell (olfaction).

Photoreceptors

Specialized neurons in the retina that detect light; includes rods and cones.

Cones

Type of photoreceptor cells responsible for color vision and high visual acuity.

Rods

Type of photoreceptor cells that detect low light levels and are responsible for night vision.

Fovea

The central region of the retina that has the highest concentration of cones and highest visual acuity.

Optic Nerve

The nerve that transmits visual information from the retina to the brain.

Retinal Ganglion Cells

The final output neurons of the retina that send visual information to the brain.

Visuospatial Processing

The ability of the brain to perceive and process visual information in terms of spatial relationships.

Nociceptive Pain

Pain resulting from damage to body tissue, typically transmitted by nociceptors.

Somatosensory Homunculus

A distorted representation of the human body in the somatosensory cortex, reflecting the density of sensory input from various body parts.

Blind Spot

The area of the retina devoid of photoreceptors where the optic nerve exits the eye.

Phototransduction

The process by which photoreceptor cells convert light into electrical signals.

Pupil

The adjustable opening in the center of the iris that regulates light entering the eye.

Iris

The colored part of the eye, which also controls the size of the pupil.

Afferent Pathways

Nerve pathways that carry sensory information from the peripheral organs to the central nervous system.

Efferent Pathways

Nerve pathways that carry signals from the central nervous system to peripheral organs.

Binaural Hearing

The ability to locate sound in space using two ears to perceive differences in time and intensity.

Tonotopic Organization

An arrangement in the auditory system where different frequencies are encoded in different locations along the cochlea.

Ciliary Muscles

Muscles in the eye that control the shape of the lens for focusing.

Extracellular Matrix (ECM)

A network of proteins and carbohydrates in the surrounding environment of cells that influences their function.

Calibration Sensitivity

The ability of sensory receptors to discern subtle differences in stimulus intensity or quality.

Action Potential Threshold

The specific level of membrane potential that must be reached for an action potential to occur.

Absolute Threshold

The minimum stimulus intensity required for detection.

Visual Cortex

The area of the brain responsible for processing visual information.

Equilibrium

The state of balance within the sensory systems, particularly relating to the vestibular system.

Angular Momentum

The quantity of rotation of an object, especially relevant in the vestibular system for balance.

Endolymph

The fluid found in the inner ear that helps with balance and hearing.

Spatial Disorientation

The inability to correctly perceive one's position in space, often due to issues with the vestibular system.

Stereocilia

Hair-like structures on hair cells in the inner ear that detect sound waves and balance changes.

Neurotransmitter Release

The process by which neurotransmitters are released from neurons to transmit signals to other neurons.

Glomeruli

Structures in the olfactory bulb where olfactory receptor neurons synapse and process smells.

Olfactory Nerve

The nerve that carries the sense of smell from the olfactory receptors to the brain.

Temporal Lobe

The brain region that processes auditory information, among other functions.

Occipital Lobe

The brain region primarily responsible for visual processing.

Paine Pathway

The neural pathway that transmits painful stimuli to the brain.

Sensory Modality

A specific sensory system, such as visual, auditory, or somatosensory.

Interneuron

A type of neuron that connects sensory and motor pathways in the central nervous system.

Somatosensory Association Areas

Brain regions that integrate and interpret sensory input from the somatosensory cortex.

Detective Sensitivity

The ability of a sensory system to detect minimal changes in stimulus intensity.

Auditory Cortex

The area of the brain that processes sound information.

Primary Somatosensory Cortex

The region of the brain responsible for processing somatosensory information from the body.

Functional Imaging

Brain imaging techniques that measure brain activity related to sensory processing.

Sensory Receptor Activation

The initial response of sensory receptors to detect stimuli.

Afferent Neurons

Neurons that carry sensory information toward the brain.

Efferent Neurons

Neurons that convey commands from the brain to the body's muscles.

Cortical Representation

The way in which sensory information is mapped in the brain.

Conscious Perception

The increased acknowledgment and awareness of sensory stimuli in the brain.

Olfactory Bulb

The neural structure involved in the sense of smell, where olfactory receptors send signals.

Pacinian Corpuscles

Mechanoreceptors in the skin that respond to pressure and vibration.

Meissner's Corpuscles

Mechanoreceptors that respond to light touch.

Ruffini's Endings

Mechanoreceptors that respond to skin stretch and deep pressure.

Pseudounipolar Neurons

Neurons with two processes that function in sensory pathways of the peripheral nervous system.

Physiological Response

The change in body function that occurs in response to sensory stimulation.

Acoustic Reflex

An involuntary muscle contraction in response to loud sound to protect hearing.

Thermal Receptors

Sensory receptors that respond to changes in temperature.

Vestibular Reflexes

Reflex actions that help maintain balance and stabilize the visual field.

Phalen's Test

A clinical test used to diagnose carpal tunnel syndrome by assessing sensory nerve conduction.

Sensation vs. Perception

Sensation refers to the initial detection of stimuli, while perception is the interpretation of those sensations.

Neuronal Firing Rate

The frequency at which neurons discharge action potentials, transmitting information regarding stimulus intensity.

Adaptation Mechanism

The physiological processes allowing sensory receptors to become less sensitive to persistent stimuli.

Pain Threshold

The minimum stimulus intensity defined as painful.

Sensory Environments

The surroundings in which sensory receptors are stimulated.

Visual Illusions

Perceptual phenomena that occur when the brain's interpretation of visual information deviates from reality.

Detective Differences

The ability to distinguish between different sensory inputs.

C-Circuit

A description sometimes used to categorize specific circuit pathways involved in sensory processing.

Adaptation of Sensory Systems

The decrease in response of sensory systems due to continuous stimulation.

Pain Modulation

The process by which the brain inhibits or enhances the perception of pain.