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Sensory System

 
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Sensory system
 
 
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A sensory system is a part of the nervous system
Nervous system

The nervous system is a Neural network of specialized cells that communicate information about an animal's surroundings and itself. It processes this information and causes reactions in other parts of the body....
 responsible for processing sensory
Sense

Senses are the physiological methods of perception. The senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, most notably neuroscience, cognitive psychology , and philosophy of perception....
 information. A sensory system consists of sensory receptor
Sensory receptor

In a sensory system, a sensory receptor is a sensory nerve ending that recognizes a stimulus in the internal or external environment of an organism....
s, neural pathway
Neural pathway

A neural pathway is a neural tract connecting one part of the nervous system with another, usually consisting of bundles of elongated, myelin-insulated neurons, known collectively as white matter....
s, and parts of the brain
Brain

The brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as cnidarian and echinoderm have a decentralized nervous system without a brain, while sponges lack any nervous system at all....
 involved in sensory perception. Commonly recognized sensory systems are those for vision, hearing
Hearing (sense)

Hearing is one of the traditional five senses. It is the ability to perceive sound by detecting vibrations via an organ such as the ear. The inability to hear is called deafness....
, somatic sensation (touch), taste
Taste

Sorry, no overview for this topic
 and olfaction
Olfaction

Olfaction refers to the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertebrates, and, by analogy, sensory cells of the antennae of invertebrates....
 (smell).

The receptive field
Receptive field

The receptive field of a sensory neuron is a region of space in which the presence of a stimulus will alter the firing of that neuron. Receptive fields have been identified for neurons of the auditory system, the somatosensory system, and the visual system....
 is the specific part of the world to which a receptor organ and receptor cells respond.






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Can you explain how the auditory, visual, and sensing part of the sensory system work?








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Gray722
A sensory system is a part of the nervous system
Nervous system

The nervous system is a Neural network of specialized cells that communicate information about an animal's surroundings and itself. It processes this information and causes reactions in other parts of the body....
 responsible for processing sensory
Sense

Senses are the physiological methods of perception. The senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, most notably neuroscience, cognitive psychology , and philosophy of perception....
 information. A sensory system consists of sensory receptor
Sensory receptor

In a sensory system, a sensory receptor is a sensory nerve ending that recognizes a stimulus in the internal or external environment of an organism....
s, neural pathway
Neural pathway

A neural pathway is a neural tract connecting one part of the nervous system with another, usually consisting of bundles of elongated, myelin-insulated neurons, known collectively as white matter....
s, and parts of the brain
Brain

The brain is the center of the nervous system in all vertebrate, and most invertebrate, animals. Some primitive animals such as cnidarian and echinoderm have a decentralized nervous system without a brain, while sponges lack any nervous system at all....
 involved in sensory perception. Commonly recognized sensory systems are those for vision, hearing
Hearing (sense)

Hearing is one of the traditional five senses. It is the ability to perceive sound by detecting vibrations via an organ such as the ear. The inability to hear is called deafness....
, somatic sensation (touch), taste
Taste

Sorry, no overview for this topic
 and olfaction
Olfaction

Olfaction refers to the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertebrates, and, by analogy, sensory cells of the antennae of invertebrates....
 (smell).

The receptive field
Receptive field

The receptive field of a sensory neuron is a region of space in which the presence of a stimulus will alter the firing of that neuron. Receptive fields have been identified for neurons of the auditory system, the somatosensory system, and the visual system....
 is the specific part of the world to which a receptor organ and receptor cells respond. For instance, the part of the world an eye can see, is its receptive field; the light that each rod
Rod

Rod may mean:*Rod , a straight and slender stick; a wand; a cylinder; hence, any slender bar*Rod cell, a cell found in the retina that is sensitive to light/dark ...
 or cone
Cone cell

Cone cells, or cones, are photoreceptor cells in the retina of the eye which function best in relatively bright light. The cone cells gradually become sparser towards the periphery of the retina....
 can see, is its receptive field. Receptive field
Receptive field

The receptive field of a sensory neuron is a region of space in which the presence of a stimulus will alter the firing of that neuron. Receptive fields have been identified for neurons of the auditory system, the somatosensory system, and the visual system....
s have been identified for the visual system
Visual system

The visual system is the part of the central nervous system which allows organisms to visual perception.It interprets the information from visible light to build a representation of the world surrounding the body....
, auditory system
Auditory system

The auditory system is the sensory system for the sense of hearing ....
 and somatosensory system
Somatosensory system

The somatosensory system is a diverse sensory system comprising the receptors and processing centres to produce the sensory modality such as touch, temperature perception, proprioception , and nociception ....
, so far.

Stimulus

Sensory systems code for four aspects of a stimulus
Stimulus (physiology)

In physiology, a stimulus is a detectable change in the internal or external environment. When a stimulus is applied to a sensory receptor, it elicits or influences a Reflex action via Transduction ....
; type (modality), intensity, location, and duration. Arrival time
Time

Time is a component of the measurement used to sequence events, to compare the durations of events and the intervals between them, and to quantify the motions of objects....
 of a sound pulse
Pulse

In medicine, a person's pulse is the throbbing of their artery. It can be palpated in any place that allows for an artery to be compressed against a bone, such as at the neck , at the wrist , behind the knee , on the inside of the elbow , and near the ankle joint ....
 and phase
Phase

A phase is one part or portion in recurring or serial activities or occurrences logically connected within a greater process, often resulting in an output or a change....
 differences of continuous sound are used for localization of sound sources. Certain receptors are sensitive to certain types of stimuli (for example, different mechanoreceptor
Mechanoreceptor

A mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion. There are four main types in the glabrous skin of humans: Pacinian corpuscles, Meissner's corpuscles, Merkel nerve ending, and Ruffini corpuscles....
s respond best to different kinds of touch stimuli, like sharp or blunt objects). Receptors send impulses
Action potential

An action potential is a self-regenerating wave of electrochemical activity that allows nerve cells to carry a signal over a distance. It is the primary electrical signal generated by nerve cells, and arises from changes in the permeability of the nerve cell's axonal Cell membranes to specific ions....
 in certain patterns to send information about the intensity of a stimulus (for example, how loud a sound is). The location of the receptor that is stimulated gives the brain information about the location of the stimulus (for example, stimulating a mechanoreceptor in a finger will send information to the brain about that finger). The duration of the stimulus (how long it lasts) is conveyed by firing patterns of receptors.

Modality


A stimulus modality
Stimulus modality

Stimulus modality also sensory modality is one aspect of a stimulus . There are many modalities: temperature, taste, sound, pressure. The type of sensory receptor activated by a stimulus plays the primary role in coding the stimulus modality....
 (sensory modality) is a type of physical phenomenon that can be sensed. Examples are temperature
Temperature

In physics, temperature is a physical property of a Physical system that underlies the common notions of hot and cold; something that feels hotter generally has the greater temperature....
, taste
Taste

Sorry, no overview for this topic
, sound
Sound

Sound is vibration transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a threshold of hearing to be heard, or the sensation stimulated in organs of hearing by such vibrations....
, and pressure
Pressure

Pressure is the force per unit area applied to an object in a direction surface normal to the surface. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure....
. The type of sensory receptor
Sensory receptor

In a sensory system, a sensory receptor is a sensory nerve ending that recognizes a stimulus in the internal or external environment of an organism....
 activated by a stimulus plays the primary role in coding the stimulus modality.

In the memory-prediction framework
Memory-prediction framework

The memory-prediction framework is a theory of brain function that was created by Jeff Hawkins and described in his book On Intelligence. This theory concerns the role of the human neocortex and its associations with the hippocampus and the thalamus in matching sensory inputs to stored memory patterns and how this process leads to predict...
, Jeff Hawkins
Jeff Hawkins

Jeff Hawkins is the founder of Palm Computing and Handspring . He has since turned to work on neuroscience full-time, founded the Helen_Wills_Neuroscience_Institute#Redwood_Center_for_Theoretical_Neuroscience in 2002, and published On Intelligence describing his memory-prediction framework theory of the brain....
 mentions a correspondence between the six layers of the cerebral cortex
Cerebral cortex

The cerebral cortex is a structure within the brain that plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness....
 and the six layers of the optic tract
Optic tract

The optic tract is a part of the visual system in the brain.It is a continuation of the optic nerve and runs from the optic chiasm to the lateral geniculate nucleus....
 of the visual system
Visual system

The visual system is the part of the central nervous system which allows organisms to visual perception.It interprets the information from visible light to build a representation of the world surrounding the body....
. The primary visual cortex has areas labelled V1, V2, V3, V4, V5, MT, IT, etc. Thus Area V1 mentioned below, is meant to signify only one class of cells in the brain, for which there can be many other cells which are also engaged in vision.

Hawkins lays out a scheme for the analogous modalities of the sensory system. Note that there can be many types of senses, some not mentioned here. In particular, for human
Human

A human being, also human or man, is a member of a species of bipedalism primates in the family Hominidae . Mitochondrial DNA evidence indicates that modern humans originated in east Africa about 200,000 years ago....
s, there will be cells
Cell (biology)

The cell is the structural and functional unit of all known Life organisms. It is the smallest unit of an organism that is classified as living, and is often called the building bricks of life....
 which can be labelled as belonging to V1, V2 A1, A2, etc.:

V1 (vision)

Visual Area 1, or V1, is used for vision, via the visual system
Visual system

The visual system is the part of the central nervous system which allows organisms to visual perception.It interprets the information from visible light to build a representation of the world surrounding the body....
 to the primary visual cortex.

Earcov

A1 (auditory - hearing)

Auditory Area 1, or A1, is for hearing, via the auditory system
Auditory system

The auditory system is the sensory system for the sense of hearing ....
, the primary auditory cortex
Primary auditory cortex

The primary auditory cortex is the region of the brain that is responsible for processing of auditory system information....
.

S1 (somatosensory - touch)

Somatosensory Area 1, or S1, is for touch and proprioception
Proprioception

Proprioception ; from Latin proprius, meaning "one's own" and perception) is the sense of the relative position of neighbouring parts of the body....
 in the somatosensory system
Somatosensory system

The somatosensory system is a diverse sensory system comprising the receptors and processing centres to produce the sensory modality such as touch, temperature perception, proprioception , and nociception ....
. The somatosensory system feeds the Brodmann Areas 3, 1 and 2
Postcentral gyrus

The lateral postcentral gyrus is a prominent structure in the parietal lobe of the human brain and an important landmark. It was initially defined from surface stimulation studies of Penfield, and parallel surface potential studies of Bard, Woolsey, and Marshall....
 of the primary somatosensory cortex
Postcentral gyrus

The lateral postcentral gyrus is a prominent structure in the parietal lobe of the human brain and an important landmark. It was initially defined from surface stimulation studies of Penfield, and parallel surface potential studies of Bard, Woolsey, and Marshall....
. But there are also pathways for proprioception
Proprioception

Proprioception ; from Latin proprius, meaning "one's own" and perception) is the sense of the relative position of neighbouring parts of the body....
 (via the cerebellum
Cerebellum

The cerebellum is a region of the brain that plays an important role in the integration of perception, coordination and motoneuron control. In order to coordinate motor control, there are many neural pathways linking the cerebellum with the cerebrum motor cortex and the spinocerebellar tract ....
), and motor
Motor neuron

In vertebrates, the term motor neuron classically applies to neurons located in the central nervous system that project their axons outside the CNS and directly or indirectly control muscles....
 control
Control

Control is used in a variety of contexts to express "mastery" or "proficiency": e.g. "Music students attending a master class are expected to have full control of basic skills such as rhythm and pitch" and more generally an ability to purposefully direct change....
 (via Brodmann area 4
Brodmann area 4

Brodmann area 4 comprises the primary motor cortex of the human brain. It is located in the posterior portion of the frontal lobe.Brodmann area 4 is about the same as the precentral gyrus....
).

Tongue

G1 (gustatory - taste)

Gustatory Area 1, or G1, is used for taste
Gustatory system

The gustatory system is the sensory system for the sense of taste....
.

O1 (olfactory - smell)


Olfactory Area 1, or O1, is used for smell. In contrast to vision and hearing, the olfactory bulb
Olfactory bulb

The olfactory bulb is a structure of the vertebrate forebrain involved in olfaction, the perception of odors....
s are not cross-hemispheric; the right bulb connects to the right hemisphere and the left bulb connects to the left hemisphere.

Human sensory system

The Human sensory system consists of the following sub-systems:
  • Visual system
    Visual system

    The visual system is the part of the central nervous system which allows organisms to visual perception.It interprets the information from visible light to build a representation of the world surrounding the body....
     consists of the photoreceptor
    Photoreceptor

    A photoreceptor, or photoreceptor cell, is a specialized type of neuron found in the eye's retina that is capable of phototransduction....
    s, optic nerve, and V1.
  • Auditory system
    Auditory system

    The auditory system is the sensory system for the sense of hearing ....
  • Somatosensory system
    Somatosensory system

    The somatosensory system is a diverse sensory system comprising the receptors and processing centres to produce the sensory modality such as touch, temperature perception, proprioception , and nociception ....
     consists of the receptors, transmitters (pathways) leading to S1, and S1 that experiences the sensations labelled as touch or pressure
    Pressure

    Pressure is the force per unit area applied to an object in a direction surface normal to the surface. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure....
    , temperature
    Temperature

    In physics, temperature is a physical property of a Physical system that underlies the common notions of hot and cold; something that feels hotter generally has the greater temperature....
     (warm or cold), pain
    Pain

    Pain, in the sense of physical pain, is a typical sensory experience that may be described as the unpleasant awareness of a noxious stimulus or bodily harm....
     (including itch
    Itch

    Itch is an unpleasant sensation that evokes the desire or reflex to scratch. Itch has resisted many attempts to classify it as any one type of sensory experience....
     and tickle), and the sensations of muscle movement and joint position including posture
    Posture

    Posture or posturing may refer to:In humans* Neutral spine or good posture* Human position* Abnormal posturing, in neurotrauma* Posturography, in neurology...
    , movement
    Locomotion

    The term locomotion means movement or travel. It may refer to:* Motion * Animal locomotion** Terrestrial locomotion* TravelLocomotion may refer to specific types of motion:...
    , and facial expression (collectively also called proprioception).
  • Gustatory system
  • Olfactory
    Olfaction

    Olfaction refers to the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertebrates, and, by analogy, sensory cells of the antennae of invertebrates....
     system


Human sensory receptors are:
  • Chemosensor
    Chemosensor

    A chemosensor, also known as chemoreceptor, is a sensory receptor that transduction a chemical signal into an action potential. Or, more generally, a chemosensor detects certain chemical stimuli in the environment....
  • Mechanoreceptor
    Mechanoreceptor

    A mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion. There are four main types in the glabrous skin of humans: Pacinian corpuscles, Meissner's corpuscles, Merkel nerve ending, and Ruffini corpuscles....
  • Nociceptor
    Nociceptor

    A nociceptor is a sensory receptor that reacts to potentially damaging stimuli by sending nerve signals to the spinal cord and brain. This process, called nociception, usually causes the perception of pain....
  • Photoreceptor
    Photoreceptor

    A photoreceptor, or photoreceptor cell, is a specialized type of neuron found in the eye's retina that is capable of phototransduction....
  • Thermoreceptor
    Thermoreceptor

    A thermoreceptor is a sensory receptor, or more accurately the receptive portion of a sensory neuron, that codes absolute and relative changes in temperature, primarily within the innocuous range....


See also

  • Sensor
    Sensor

    A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated glass tube....
  • Sensory neuroscience
    Sensory neuroscience

    Sensory neuroscience is a subfield of neuroscience which explores the anatomy and physiology of neurons that are part of sensory systems such as vision, hearing, and olfaction....