Wikia

Psychology Wiki

Changes: Mechanoreceptors

Edit

Back to page

(External links)
(update wp)
Line 1: Line 1:
 
{{BioPsy}}
 
{{BioPsy}}
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 corpuscle]]s, [[Meissner's corpuscle]]s, [[Merkel nerve ending|Merkel's discs]], and [[Ruffini corpuscles]]. There are also mechanoreceptors in the hairy skin, and the hair cells in the cochlea are the most sensitive mechanoreceptors in tranducing air pressure waves into sound.
+
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 corpuscle]]s, [[Meissner's corpuscle]]s, [[Merkel nerve ending|Merkel's discs]], and [[Ruffini corpuscle]]s. There are also mechanoreceptors in hairy skin, and the hair cells in the cochlea are the most sensitive mechanoreceptors, transducing air pressure waves into nerve signals sent to the brain. In the [[periodontal ligament]], there are some mechanoreceptors, which allow the jaw to relax when biting down on hard objects; the [[mesencephalic nucleus]] is responsible for this reflex.
   
 
==Mechanism of sensation==
 
==Mechanism of sensation==
Mechanoreceptors are primary neurons that respond to mechanical stimuli by firing action potentials. Peripheral transduction is believed to occur in the end-organs.
+
Mechanoreceptors are primary neurons that respond to mechanical stimuli by firing [[action potential]]s. [[transduction (physiology)|Peripheral transduction]] is believed to occur in the end-organs.
   
In [[somatosensory]] [[sensory transduction|transduction]], the [[afferent neuron]]s transmit the message through a [[synapse]] in the [[dorsal column nuclei]], where another neuron sends the signal to the [[thalamus]], where another neuron sends the signal to the [[somatosensory cortex]].
+
In [[somatosensory]] [[sensory transduction|transduction]], the [[afferent neuron]]s transmit messages through [[synapse]]s in the [[dorsal column nuclei]], where second-order neurons send the signal to the [[thalamus]] and synapse with third-order neurons in the [[ventrobasal complex]]. The third-order neurons then send the signal to the [[somatosensory cortex]].
   
 
===Feedback===
 
===Feedback===
More recent work has expanded the role of the mechanoreceptors for feedback in fine motor control. Single action potentials from RAI and PC afferents are directly linked to activation of related hand muscles,<ref>[McNulty and Macefield J Physiol. 2001 Dec 15;537(Pt 3):1021-32]</ref> whereas SAI activatio does not trigger muscle activity.
+
More recent work has expanded the role of the cutaneous mechanoreceptors for feedback in fine motor control.<ref>[Johansson and Flanagan, Nature Reviews Neuroscience, 2009, 10: 345-359]</ref> Single action potentials from RAI and PC afferents are directly linked to activation of related hand muscles,<ref>[McNulty and Macefield J Physiol. 2001 Dec 15;537(Pt 3):1021-32]</ref> whereas SAI activation does not trigger muscle activity.
   
 
==History==
 
==History==
The human work stemmed from Vallbo and Johansson's percutaneous recordings from human volunteers in the late 1970s. Work in rhesus monkeys has found virtually identical mechanoreceptors with the exception of Ruffini corpuscles which are not found in the monkey.
+
Work on humans stemmed from Vallbo and Johansson's percutaneous recordings from human volunteers in the late 1970s.<ref>[Johansson and Vallbo, 1983, Trends in Neurosci. 6: 27-31]</ref> Work in [[rhesus monkey]]s has found virtually identical mechanoreceptors with the exception of Ruffini corpuscles, which are not found in the monkey.
   
 
==Types==
 
==Types==
Mechanoreceptors are mainly cutaneous ones, but there are also other types, e.g. [[hair cells]].
 
 
 
===Cutaneous=== <!--Cutaneous mechanoreceptors redirects here-->
 
===Cutaneous=== <!--Cutaneous mechanoreceptors redirects here-->
Cutaneous mechanoreceptors are located in the skin, like other [[cutaneous receptors]]. They are all innervated by [[Aβ fibers]], except the mechanorecepting [[free nerve endings]], which are innervated by [[Aδ fibers]]. They can be categorized both by morphology, by what kind of sensation they perceive and by the rate of adaption. Furthermore, they have different [[receptive field]].
+
Cutaneous mechanoreceptors are located in the skin, like other [[cutaneous receptors]]. They are all innervated by [[Aβ fibers]], except the mechanorecepting [[free nerve endings]], which are innervated by [[A delta fiber|Aδ fibers]]. They can be categorized by morphology, by what kind of sensation they perceive and by the rate of adaptation. Furthermore, each has a different [[receptive field]].
   
 
====By morphology==== <!--Hair follicle receptor redirects here-->
 
====By morphology==== <!--Hair follicle receptor redirects here-->
*[[Ruffini's end organ]] detects sustained pressure.
+
*[[Ruffini's end organ]]s detect tension deep in the skin.
*[[Meissner's corpuscle]] detects changes in texture (vibrations around 50 Hz); adapts rapidly.
+
*[[Meissner's corpuscle]]s detect changes in texture (vibrations around 50&nbsp;Hz) and adapt rapidly.
*[[Pacinian corpuscle]] detects deep pressure and rapid vibrations (about 200-300 Hz).
+
*[[Pacinian corpuscle]]s detect rapid vibrations (about 200–300&nbsp;Hz).
*[[Merkel's disc]] detects sustained touch and pressure.
+
*[[Merkel's disc]]s detect sustained touch and pressure.
*Mechanorecepting [[Free nerve endings]] ((touch, pressure, stretch)
+
*Mechanoreceiving [[free nerve ending]]s detect touch, pressure and stretching
*''Hair follicle receptors'' are located in [[hair follicles]] and sense the position of hairs.
+
*[[Hair follicle receptors]] are located in [[hair follicle]]s and sense position changes of [[hair]]s.
   
 
====By sensation====
 
====By sensation====
Line 31: Line 29:
 
Cutaneous mechanoreceptors provide the senses of touch, pressure, vibration, [[proprioception]] and others.
 
Cutaneous mechanoreceptors provide the senses of touch, pressure, vibration, [[proprioception]] and others.
   
*The '''SAI type mechanoreceptor''', with the Merkel cell end-organ, underlies the perception of form and roughness on the skin.<ref>[Johnson and Hsiao, Annual Review of Neuroscience, 1992; 15:227-50]</ref>
+
*The '''Slowly Adapting type 1 (SA1) mechanoreceptor''', with the Merkel cell end-organ, underlies the perception of form and roughness on the skin.<ref>[Johnson and Hsiao, Annual Review of Neuroscience, 1992; 15:227-50]</ref> They have small receptive fields and produce sustained responses to static stimulation.
   
*The '''RAI type mechanoreceptor''' underlies the perception of flutter,<ref>[Talbot et al J Neurophysiol. 1968 Mar;31(2):301-34]</ref> and slip on the skin.<ref>[Johansson and Westling Exp Brain Res. 1987;66(1):141-54]</ref>
+
*The '''Slowly Adapting type 2 (SA2) mechanoreceptors''' respond to skin stretch, but have not been closely linked to either proprioceptive or mechanoreceptive roles in perception.<ref>[Toerbjork and Ochoa Acta Physiol Scand. 1980 Dec;110(4):445-7]</ref> They also produce sustained responses to static stimulation, but have large receptive fields.
   
*'''Pacinian receptors''' underlie the perception of high frequency vibration.<ref>[Talbot et al J Neurophysiol. 1968 Mar;31(2):301-34]</ref> SAII mechanoreceptors respond to skin stretch, but have not been closely linked to either proprioceptive or mechanoreceptive roles in perception.<ref>[Toerbjork and Ochoa Acta Physiol Scand. 1980 Dec;110(4):445-7]</ref>
+
*The '''Rapidly Adapting (RA) mechanoreceptor''' underlies the perception of flutter<ref>[Talbot et al. J Neurophysiol. 1968 Mar;31(2):301-34]</ref> and slip on the skin.<ref>[Johansson and Westling Exp Brain Res. 1987;66(1):141-54]</ref> They have small receptive fields and produce transient responses to the onset and offset of stimulation.
   
====By rate of adaption==== <!--Rapidly adapting cutaneous mechanoreceptors, Slowly adapting cutaneous mechanoreceptors, rapidly adapting, intermediate adapting and slowly adapting redirect here-->
+
*'''Pacinian receptors''' underlie the perception of high frequency vibration.<ref>[Talbot et al. J Neurophysiol. 1968 Mar;31(2):301-34]</ref> They also produce transient responses, but have large receptive fields.
Cutaneous mechanoreceptors can also be separated into categories based on their rates of adaptivity. When a mechanoreceptor receives a stimulus it begins to fire impulses or [[action potential]]s at an elevated frequency (the stronger the stimulus the higher the frequency). The cell, however, will soon “adapt” to a constant or static stimulus and the pulses will subside to a normal rate. Receptors that adapt quickly (i.e. quickly return to a normal pulse rate) are referred to as ‘’phasic’’. Those receptors that are slow to return to their normal firing rate are called ‘’tonic’’. Phasic mechanoreceptors are useful in sensing such things as texture, vibrations, etc; whereas tonic receptors are useful for temperature and [[proprioception]] among others.
 
   
*'''Slowly adapting'''
+
====By rate of adaptation==== <!--Rapidly adapting cutaneous mechanoreceptors, Slowly adapting cutaneous mechanoreceptors, rapidly adapting, intermediate adapting and slowly adapting redirect here-->
Slowly adapting mechanoreceptors include [[Merkel corpuscle end-organ|Merkel]] and [[Ruffini corpuscle end-organ]]s, some [[free nerve endings]].
+
Cutaneous mechanoreceptors can also be separated into categories based on their rates of adaptation. When a mechanoreceptor receives a stimulus, it begins to fire impulses or [[action potential]]s at an elevated frequency (the stronger the stimulus, the higher the frequency). The cell, however, will soon "adapt" to a constant or static stimulus, and the pulses will subside to a normal rate. Receptors that adapt quickly (i.e. quickly return to a normal pulse rate) are referred to as "phasic". Those receptors that are slow to return to their normal firing rate are called "tonic". Phasic mechanoreceptors are useful in sensing such things as texture or vibrations, whereas tonic receptors are useful for temperature and [[proprioception]] among others.
**Slowly adapting type I mechanoreceptors have multiple [[Merkel corpuscle end-organ]]s.
 
**Slowly adapting type II mechanoreceptors have single [[Ruffini corpuscle end-organ]]s.
 
   
*'''Intermediate adapting'''
+
*'''Slowly adapting''': Slowly adapting mechanoreceptors include [[Merkel corpuscle end-organ|Merkel]] and [[Ruffini corpuscle end-organ]]s, and some [[free nerve endings]].
Some [[free nerve endings]] are intermediate adapting.
+
**Slowly adapting type I mechanoreceptors have multiple [[Merkel corpuscle end-organ]]s.
  +
**Slowly adapting type II mechanoreceptors have single [[Ruffini corpuscle end-organ]]s.
   
*'''Rapidly adapting'''
+
*'''Intermediate adapting''': Some [[free nerve endings]] are intermediate adapting.
Rapidly adapting mechanoreceptors include [[Meissner corpuscle end-organ]]s, [[Pacinian corpuscle end-organs]], [[hair follicle receptors]] and some [[free nerve endings]].
+
  +
*'''Rapidly adapting''': Rapidly adapting mechanoreceptors include [[Meissner corpuscle end-organ]]s, [[Pacinian corpuscle end-organs]], [[hair follicle receptors]] and some [[free nerve endings]].
 
**Rapidly adapting type I mechanoreceptors have multiple [[Meissner corpuscle end-organ]]s.
 
**Rapidly adapting type I mechanoreceptors have multiple [[Meissner corpuscle end-organ]]s.
 
**Rapidly adapting type II mechanoreceptors (usually called Pacinian) have single [[Pacinian corpuscle end-organs]].
 
**Rapidly adapting type II mechanoreceptors (usually called Pacinian) have single [[Pacinian corpuscle end-organs]].
   
 
====Receptive field====
 
====Receptive field====
Cutaneous mechanoreceptors with small, accurate [[receptive field]]s are found in areas needing accurate taction (e.g. the fingertips). In the fingertips and lips, innervation density of slowly adapting type I and rapidly adapting type I mechanoreceptors are greatly increased. These two types of mechanoreceptors have small discrete receptive fields and are thought to underly most low threshold use of the fingers in assessing texture, surface slip, and flutter. Mechanoreceptors found in areas of the body with less tactile acuity tend to have larger [[receptive fields]].
+
Cutaneous mechanoreceptors with small, accurate [[receptive field]]s are found in areas needing accurate taction (e.g. the fingertips). In the fingertips and lips, innervation density of slowly adapting type I and rapidly adapting type I mechanoreceptors are greatly increased. These two types of mechanoreceptors have small discrete receptive fields and are thought to underlie most low-threshold use of the fingers in assessing texture, surface slip, and flutter. Mechanoreceptors found in areas of the body with less tactile acuity tend to have larger [[receptive fields]].
   
 
===Others===
 
===Others===
Other mechanoreceptors than cutaneous ones include the [[hair cells]], which are [[sensory receptors]] in the [[vestibular system]] in the [[inner ear]], where they contribute to the [[auditory system]] and [[equilibrioception]].
+
Other mechanoreceptors than cutaneous ones include the [[hair cell]]s, which are [[sensory receptor]]s in the [[vestibular system]] of the [[inner ear]], where they contribute to the [[auditory system]] and [[equilibrioception]].
  +
  +
There are also [[Juxtacapillary (J) receptors]], which respond to events such as [[pulmonary edema]], [[pulmonary embolism|pulmonary emboli]], [[pneumonia]], and [[barotrauma]].
  +
  +
==Pacinian Corpuscle==
  +
{{main|Pacinian Corpuscle}}
  +
Pacinian corpuscles are pressure receptors located in the skin and also in various internal organs. Each is connected to a sensory neuron.
  +
Because of its relatively large size, a single Pacinian corpuscle can be isolated and its properties studied. Mechanical pressure of varying strength and frequency can be applied to the corpuscle by stylus, and the resulting electrical activity detected by electrodes attached to the preparation.
  +
  +
Deforming the corpuscle creates a generator potential in the sensory neuron arising within it. This is a graded response: the greater the deformation, the greater the generator potential. If the generator potential reaches threshold, a volley of action potentials (nerve impulses) are triggered at the first [[node of Ranvier]] of the sensory neuron.
  +
  +
Once threshold is reached, the magnitude of the stimulus is encoded in the frequency of impulses generated in the neuron. So the more massive or rapid the deformation of a single corpuscle, the higher the frequency of nerve impulses generated in its neuron.
  +
  +
The optimal sensitivity of a Pacinian corpuscle is 250&nbsp;Hz, the frequency range generated upon finger tips by textures made of features smaller than 200&nbsp;[[micrometre]]s.<ref>Scheibert J, Leurent S, Prevost A, Debrégeas G. (2009). The role of fingerprints in the coding of tactile information probed with a biomimetic sensor. Science. 323(5920):1503-6. PMID 19179493 {{DOI|10.1126/science.1166467 }}</ref>
  +
  +
==Muscle Spindles and the Stretch Reflex==
  +
  +
The [[knee jerk]] is the popularly known [[stretch reflex]] (involuntary kick of the lower leg) induced by a physician tapping the knee with a rubber-headed hammer. The hammer strikes a [[tendon]] that [[insertion (anatomy)|inserts]] an [[extensor]] muscle in the front of the thigh into the lower leg. Tapping the tendon stretches the thigh muscle, which activates [[stretch receptor]]s within the muscle called [[muscle spindle]]s. Each muscle spindle consists of sensory nerve endings wrapped around special muscle fibers called [[spindle fiber]]s (also called intrafusal fibers). Stretching a spindle fiber initiates a volley of impulses in the sensory neuron (a [[Type Ia sensory fiber|I-a]] neuron) attached to it. The impulses travel along the sensory axon to the spinal cord where they form several kinds of synapses:
  +
  +
# Some of the branches of the I-a axons synapse directly with [[alpha motor neuron]]s.These carry impulses back to the same muscle causing it to contract. The leg straightens.
  +
# Some of the branches of the I-a axons synapse with inhibitory interneurons in the spinal cord. These, in turn, synapse with motor neurons leading back to the antagonistic muscle, a flexor in the back of the thigh. By inhibiting the flexor, these interneurons aid contraction of the extensor.
  +
# Still other branches of the I-a axons synapse with interneurons leading to brain centers, e.g., the cerebellum, that coordinate body movements.<ref>[http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/M/Mechanoreceptors.html Source]</ref>
  +
  +
==Notes==
  +
<references/>
  +
  +
==See also==
  +
*[[Somatosensory system]]
  +
*[[Thermoreceptor]]
  +
*[[Nociceptor]]
  +
*[[Vestibular system]]
   
 
==Notes==
 
==Notes==
Line 75: Line 73:
 
[[category:Sensory neurons]]
 
[[category:Sensory neurons]]
 
[[Category:Sensory receptors]]
 
[[Category:Sensory receptors]]
  +
[[Category:Sensory system]]
  +
   
 
<!--
 
<!--
  +
[[ca:Mecanoreceptor]]
  +
[[cs:Mechanoreceptor]]
 
[[de:Mechanorezeptor]]
 
[[de:Mechanorezeptor]]
[[fr:mécanorécepteur]]
+
[[es:Mecanorreceptor]]
  +
[[fr:Mécanorécepteur]]
 
[[mk:Механорецептор]]
 
[[mk:Механорецептор]]
 
[[ja:機械受容器]]
 
[[ja:機械受容器]]
  +
[[pt:Mecanorreceptor]]
  +
[[ru:Механорецептор]]
 
[[fi:Mekanoreseptori]]
 
[[fi:Mekanoreseptori]]
  +
[[sv:Känselreceptorer]]
  +
[[uk:Механорецептор]]
  +
[[zh:机械感受器]]
 
-->
 
-->
 
{{enWP|Mechanoreceptor}}
 
{{enWP|Mechanoreceptor}}

Revision as of 11:26, November 26, 2011

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)


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's discs, and Ruffini corpuscles. There are also mechanoreceptors in hairy skin, and the hair cells in the cochlea are the most sensitive mechanoreceptors, transducing air pressure waves into nerve signals sent to the brain. In the periodontal ligament, there are some mechanoreceptors, which allow the jaw to relax when biting down on hard objects; the mesencephalic nucleus is responsible for this reflex.

Mechanism of sensation

Mechanoreceptors are primary neurons that respond to mechanical stimuli by firing action potentials. Peripheral transduction is believed to occur in the end-organs.

In somatosensory transduction, the afferent neurons transmit messages through synapses in the dorsal column nuclei, where second-order neurons send the signal to the thalamus and synapse with third-order neurons in the ventrobasal complex. The third-order neurons then send the signal to the somatosensory cortex.

Feedback

More recent work has expanded the role of the cutaneous mechanoreceptors for feedback in fine motor control.[1] Single action potentials from RAI and PC afferents are directly linked to activation of related hand muscles,[2] whereas SAI activation does not trigger muscle activity.

History

Work on humans stemmed from Vallbo and Johansson's percutaneous recordings from human volunteers in the late 1970s.[3] Work in rhesus monkeys has found virtually identical mechanoreceptors with the exception of Ruffini corpuscles, which are not found in the monkey.

Types

Cutaneous

Cutaneous mechanoreceptors are located in the skin, like other cutaneous receptors. They are all innervated by Aβ fibers, except the mechanorecepting free nerve endings, which are innervated by Aδ fibers. They can be categorized by morphology, by what kind of sensation they perceive and by the rate of adaptation. Furthermore, each has a different receptive field.

By morphology

By sensation

Cutaneous mechanoreceptors provide the senses of touch, pressure, vibration, proprioception and others.

  • The Slowly Adapting type 1 (SA1) mechanoreceptor, with the Merkel cell end-organ, underlies the perception of form and roughness on the skin.[4] They have small receptive fields and produce sustained responses to static stimulation.
  • The Slowly Adapting type 2 (SA2) mechanoreceptors respond to skin stretch, but have not been closely linked to either proprioceptive or mechanoreceptive roles in perception.[5] They also produce sustained responses to static stimulation, but have large receptive fields.
  • The Rapidly Adapting (RA) mechanoreceptor underlies the perception of flutter[6] and slip on the skin.[7] They have small receptive fields and produce transient responses to the onset and offset of stimulation.
  • Pacinian receptors underlie the perception of high frequency vibration.[8] They also produce transient responses, but have large receptive fields.

By rate of adaptation

Cutaneous mechanoreceptors can also be separated into categories based on their rates of adaptation. When a mechanoreceptor receives a stimulus, it begins to fire impulses or action potentials at an elevated frequency (the stronger the stimulus, the higher the frequency). The cell, however, will soon "adapt" to a constant or static stimulus, and the pulses will subside to a normal rate. Receptors that adapt quickly (i.e. quickly return to a normal pulse rate) are referred to as "phasic". Those receptors that are slow to return to their normal firing rate are called "tonic". Phasic mechanoreceptors are useful in sensing such things as texture or vibrations, whereas tonic receptors are useful for temperature and proprioception among others.

Receptive field

Cutaneous mechanoreceptors with small, accurate receptive fields are found in areas needing accurate taction (e.g. the fingertips). In the fingertips and lips, innervation density of slowly adapting type I and rapidly adapting type I mechanoreceptors are greatly increased. These two types of mechanoreceptors have small discrete receptive fields and are thought to underlie most low-threshold use of the fingers in assessing texture, surface slip, and flutter. Mechanoreceptors found in areas of the body with less tactile acuity tend to have larger receptive fields.

Others

Other mechanoreceptors than cutaneous ones include the hair cells, which are sensory receptors in the vestibular system of the inner ear, where they contribute to the auditory system and equilibrioception.

There are also Juxtacapillary (J) receptors, which respond to events such as pulmonary edema, pulmonary emboli, pneumonia, and barotrauma.

Pacinian Corpuscle

Main article: Pacinian Corpuscle

Pacinian corpuscles are pressure receptors located in the skin and also in various internal organs. Each is connected to a sensory neuron. Because of its relatively large size, a single Pacinian corpuscle can be isolated and its properties studied. Mechanical pressure of varying strength and frequency can be applied to the corpuscle by stylus, and the resulting electrical activity detected by electrodes attached to the preparation.

Deforming the corpuscle creates a generator potential in the sensory neuron arising within it. This is a graded response: the greater the deformation, the greater the generator potential. If the generator potential reaches threshold, a volley of action potentials (nerve impulses) are triggered at the first node of Ranvier of the sensory neuron.

Once threshold is reached, the magnitude of the stimulus is encoded in the frequency of impulses generated in the neuron. So the more massive or rapid the deformation of a single corpuscle, the higher the frequency of nerve impulses generated in its neuron.

The optimal sensitivity of a Pacinian corpuscle is 250 Hz, the frequency range generated upon finger tips by textures made of features smaller than 200 micrometres.[9]

Muscle Spindles and the Stretch Reflex

The knee jerk is the popularly known stretch reflex (involuntary kick of the lower leg) induced by a physician tapping the knee with a rubber-headed hammer. The hammer strikes a tendon that inserts an extensor muscle in the front of the thigh into the lower leg. Tapping the tendon stretches the thigh muscle, which activates stretch receptors within the muscle called muscle spindles. Each muscle spindle consists of sensory nerve endings wrapped around special muscle fibers called spindle fibers (also called intrafusal fibers). Stretching a spindle fiber initiates a volley of impulses in the sensory neuron (a I-a neuron) attached to it. The impulses travel along the sensory axon to the spinal cord where they form several kinds of synapses:

  1. Some of the branches of the I-a axons synapse directly with alpha motor neurons.These carry impulses back to the same muscle causing it to contract. The leg straightens.
  2. Some of the branches of the I-a axons synapse with inhibitory interneurons in the spinal cord. These, in turn, synapse with motor neurons leading back to the antagonistic muscle, a flexor in the back of the thigh. By inhibiting the flexor, these interneurons aid contraction of the extensor.
  3. Still other branches of the I-a axons synapse with interneurons leading to brain centers, e.g., the cerebellum, that coordinate body movements.[10]

Notes

  1. [Johansson and Flanagan, Nature Reviews Neuroscience, 2009, 10: 345-359]
  2. [McNulty and Macefield J Physiol. 2001 Dec 15;537(Pt 3):1021-32]
  3. [Johansson and Vallbo, 1983, Trends in Neurosci. 6: 27-31]
  4. [Johnson and Hsiao, Annual Review of Neuroscience, 1992; 15:227-50]
  5. [Toerbjork and Ochoa Acta Physiol Scand. 1980 Dec;110(4):445-7]
  6. [Talbot et al. J Neurophysiol. 1968 Mar;31(2):301-34]
  7. [Johansson and Westling Exp Brain Res. 1987;66(1):141-54]
  8. [Talbot et al. J Neurophysiol. 1968 Mar;31(2):301-34]
  9. Scheibert J, Leurent S, Prevost A, Debrégeas G. (2009). The role of fingerprints in the coding of tactile information probed with a biomimetic sensor. Science. 323(5920):1503-6. PMID 19179493
    1. REDIRECT Template:Doi
  10. Source

See also

Notes


See also

External links

Nervous system - Sensory system - edit
Special sensesVisual system | Auditory system | Olfactory system | Gustatory system
Somatosensory systemNociception | Thermoreception | Vestibular system |
Mechanoreception (Pressure, Vibration & Proprioception) | Equilibrioception 




This page uses Creative Commons Licensed content from Wikipedia (view authors).

Around Wikia's network

Random Wiki