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Encyclopedia > Sensory receptor
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In a sensory system, a sensory receptor is a structure that recognizes a stimulus in the internal or external environment of an organism. In response to stimuli the sensory receptor initiates sensory transduction by creating graded potentials or action potentials in the same cell or in an adjacent one. Image File history File links No higher resolution available. ... This article or section may be confusing for some readers, and should be edited to be clearer or more simplified. ... In physiology, a stimulus is a detectable change in the internal or external environment. ... “Life on Earth” redirects here. ... In physiology, transduction is the conversion of a stimulus from one form to another. ... Transmembrane potential difference is the electrical potential difference across a plasma membrane. ... A. A schematic view of an idealized action potential illustrates its various phases as the action potential passes a point on a cell membrane. ...

Contents

Location

The sensory receptor may be a specialized portion of the plasma membrane, or a separate cell associated with a neuron ending.


Functions

The sensory receptors involved in taste and smell contain receptors that bind to specific chemicals. Odor receptors in olfactory receptor neurons, for example, are activated by interacting with molecular structures on the odor molecule. Similarly, taste receptors (gustatory receptors) in taste buds interact with chemicals in food to produce an action potential. In biochemistry, a receptor is a protein on the cell membrane or within the cytoplasm or cell nucleus that binds to a specific molecule (a ligand), such as a neurotransmitter, hormone, or other substance, and initiates the cellular response to the ligand. ... Olfactory receptors are a type of G protein-coupled receptor in olfactory receptor neurons. ... Bold text == Headline text == minni hi. ... “Aroma” redirects here. ... Taste is one of the traditional five senses and refers to the ability to detect the flavor of foodstuffs and other substances (e. ... Taste buds are small structures on the upper surface of the tongue, soft palate, and epiglottis that provide information about the taste of food being eaten. ... A. A schematic view of an idealized action potential illustrates its various phases as the action potential passes a point on a cell membrane. ...


Other receptors such as mechanoreceptors and photoreceptors respond to physical stimuli. For example, photoreceptor cells contain specialized proteins such as rhodopsin to transduce the physical energy in light into electrical signals. Some types of mechanoreceptors fire action potentials when their membranes are physically stretched. A mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion. ... A photoreceptor, or photoreceptor cell, is a specialized type of neuron found in the eyes retina that is capable of phototransduction. ... This article is about cellular photoreceptors. ... A rhodopsin molecule (yellow) with bound retinal (orange), embedded in a cell membrane (lipids shown as green, head groups as red/blue). ... In physiology, transduction is the conversion of a stimulus from one form to another. ...


The sensory receptor functions as the first component in a sensory system.


Sensory receptors respond to specific stimulus modalities. The stimulus modality to which a sensory receptor responds is determined by the sensory receptor's adequate stimulus. The adequate stimulus is a property of a sensory receptor that determines the type of energy to which a sensory receptor responds to with the initiation of sensory transduction. ...


The sensory receptor responds to its stimulus modality by initiating sensory transduction. This may be accomplished by a net shift in the initial states of a receptor(see a picture of these putative states [1] with the biophysical description - link [2]).


Classification

by adequate stimulus

A sensory receptor's adequate stimulus is the stimulus modality for which it possesses the adequate sensory transduction apparatus. Adequate stimulus can be used to classify sensory receptors: In physiology, transduction is the conversion of a stimulus from one form to another. ...

Baroreceptors (or baroceptors) in the human body detect the pressure of blood flowing though them, and can send messages to the central nervous system to increase or decrease total peripheral resistance and cardiac output. ... A Chemosensor, also known as chemoreceptor, is a cell or group of cells that transduce a chemical signal into an action potential. ... A mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion. ... Figure 1  Stress tensor In physics, stress is the internal distribution of forces within a body that balance and react to the loads applied to it. ... A nociceptor is a sensory receptor that sends signals that cause the perception of pain in response to potentially damaging stimulus. ... An osmoreceptor is a sensory receptor primarily found in the hypothalamus of most homeothermic organisms that detects changes in osmotic pressure. ... Osmolality, in biology and chemistry, is a measure of moles of solute per kg of water. ... A photoreceptor, or photoreceptor cell, is a specialized type of neuron found in the eyes retina that is capable of phototransduction. ... Proprioception (from Latin proprius, meaning ones own and perception) is the sense of the position of parts of the body, relative to other neighbouring parts of the body. ... A thermoreceptor is a sensory receptor that responds to temperature, primarily within the innocuous range. ...

by location

Sensory receptors can be classified by location:

A cutaneous receptor is a types of sensory receptor found in the dermis or epidermis. ... A muscle spindle is a specialized muscle structure innervated by both sensory and motor neuron axons. ...

by morphology

Somatic sensory receptors near the surface of the skin can usually be divided into two groups based on morphology:

  • Free nerve endings characterize the nociceptors and thermoreceptors and are called thus because the terminal branches of the neuron are unmyelinated and spread throughout the dermis and epidermis.
  • Encapsulated receptors consist of the remaining types of cutaneous receptors. Encapsulation exists for specialized functioning.

A free nerve ending (FNE) is an unspecialized, afferent nerve ending, meaning it brings information from the bodys periphery to the brain. ... A nociceptor is a sensory receptor that sends signals that cause the perception of pain in response to potentially damaging stimulus. ... A thermoreceptor is a sensory receptor that responds to temperature, primarily within the innocuous range. ... The dermis is a layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. ... Cross-section of all skin layers Optical Coherence Tomography tomogram of fingertip, depicting stratum corneum (~500µm thick) with stratum disjunctum on top and stratum lucidum (connection to stratum spinosum) in the middle. ...

See also

Senses are the physiological methods of perception. ... The mechanism of the reflex arc Sensory neurons (neurones) are nerve cells within the nervous system responsible for converting external stimuli from the organisms environment into internal electrical motor reflex loops and several forms of involuntary behavior, including pain avoidance. ... // Proprioception (PRO-pree-o-SEP-shun (IPA pronunciation: ); from Latin proprius, meaning ones own and perception) is the sense of the relative position of neighbouring parts of the body. ...

External links

  • MeSH Sensory+Receptors

  Results from FactBites:
 
NationMaster - Encyclopedia: Special senses (810 words)
A mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion.
In a sensory system, a sensory receptor is a structure that recognizes a stimulus in the internal or external environment of an organism.
However, touch (along with the senses of pressure, temperature, and pain) is one of the general senses that has small sensory receptors scattered throughout the body in the skin (for a further discussion, see chapter 4).
Effects of Deuterium Oxide on Mechano-Sensory Receptor -- Nakajima and Kuroda 73 (12): 4703 -- Proceedings of the ... (164 words)
In the crayfish stretch receptor organ, a total substitution of D
O in the bathing solution produced a decrease in the amplitude of the receptor potential to a level of 34% of the control.
The electrical resistance of the receptor neuron was slightly increased by the D
  More results at FactBites »

 
 

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