NationMaster - Encyclopedia: Thermoreceptor

A thermoreceptor is a sensory receptor that responds to temperature, primarily within the innocuous range. In the mammalian peripheral nervous system warm receptors are thought to be unmyelinated C-fibres (slow conduction velocity), while those responding to cold have thinly myelinated Aδ axons (faster conduction velocity). In a sensory system, a sensory receptor is a structure that recognizes a stimulus in the internal or external environment of an organism. ... In neuroscience, myelin is an electrically insulating phospholipid layer that surrounds the axons of many neurons. ...

A special form of thermoreceptor is found in some snakes, the viper pit organ and this specialised structure is sensitive to energy in the infrared part of the spectrum. Image of a small dog taken in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of microwave radiation. ...

Location

In mammals, temperature receptors innnervate various tissues including the skin, cornea and bladder. Neurons from the pre-optic and hypothalamic regions of the brain that respond to small changes in temperature have also been described, providing information on core temperature. The hypothalamus is involved in thermoregulation, the thermoreceptors allowing feed-forward responses to a predicted change in core body temperature in response to changing environmental conditions. The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, providing most of an eyes optical power [1]. Together with the lens, the cornea refracts light and, as a result, helps the eye to focus. ... Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when temperature surrounding is very different. ... Feed-forward is a term describing a kind of system which reacts to changes in its environment, usually to maintain some desired state of the system. ...

Structure

Thermoreceptors have been classically described as having 'free' non-specialised endings; the mechanism of activation in response to temperature changes is not completely understood. However, it is likely that proteins of the Transient Receptor Potential (TRP) family as well as some specific potassium channels (two-pore domain) are involved. NERVE ENDINGS SUCK PENIS!!! ...

Function

Cold-sensitive thermoreceoptors give rise to the sensations of cooling, cold and freshness. In the cornea cold receptors are thought to respond with an increase in firing rate to cooling produced by evaporation of lacrimal fluid 'tears' and thereby to elicit a reflex blink.

Warm and cold receptors play a part in sensing innocuous environmetal temperature. Temperatures likely to damage an organism are sensed by sub-categories of nociceptors that may respond to noxious cold, noxious heat or more than one noxious stimulus modality (i.e they are polymodal). A nociceptor is a sensory receptor that responds only after a high level of stimuli or a level enough to hurt the individual. ...

Category: Sensory receptors The nervous system of an animal coordinates the activity of the muscles, monitors the organs, constructs and also stops input from the senses, and initiates actions. ... (See also sense) A sensory system is a part of the nervous system that consists of sensory receptors, neural pathways, and those parts of the brain responsible for processing the information. ... The somatosensory system is the sensory system of somatic sensation. ... Cross-section through cervical spinal cord. ... The medial lemniscus, also known as Reils band or Reils ribbon, is a pathway in the brainstem, that carries sensory information from the gracile and cuneate nuclei to the thalamus. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Pressure (symbol: p) is the force per unit area acting on a surface in a direction perpendicular to that surface. ... See Oscillator (disambiguation) for particular types of oscillation and oscillators. ... 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. ... The spinothalamic tract is the sensory pathway in the body that transmits pain, temperature, itch and crude touch. ... Pain is an unpleasant sensation which may be associated with actual or potential tissue damage and which may have physical and emotional components. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... In a sensory system, a sensory receptor is a structure that recognizes a stimulus in the internal or external environment of an organism. ... A Pacinian corpuscle is a structure that functions as a mechanoreceptor. ... Meissners corpuscles (discovered by the anatomist Georg Meissner (1829-1903) are a type of mechanoreceptor and more specifically, a tactile corpuscle(corpusculum tactus). ... Merkel nerve endings are mechanoreceptors found in the skin and mucosa of vertebrates that provide touch information to the brain. ... Ruffini Endings are one of the four main cutaneous mechanoreceptors. ... NERVE ENDINGS SUCK PENIS!!! ... A hair follicle is part of the skin that grows hair by packing old cells together. ... Organ of Golgi (neurotendinous spindle) from the human tendo calcaneus. ... A muscle spindle is a specialized muscle structure innervated by both sensory and motor neuron axons. ... Intrafusal fibers are muscle fibers that comprise the muscle spindle. ... A nociceptor is a sensory receptor that responds only after a high level of stimuli or a level enough to hurt the individual. ... The nervous system of an animal coordinates the activity of the muscles, monitors the organs, constructs and also stops input from the senses, and initiates actions. ... (See also sense) A sensory system is a part of the nervous system that consists of sensory receptors, neural pathways, and those parts of the brain responsible for processing the information. ... In medicine, Special senses is the term used to describe the senses of vision, hearing, taste, and smell. ... The visual system is the part of the nervous system which allows organisms to see. ... The auditory system is the sensory system for the sense of hearing. ... The olfactory system is the sensory system used for olfaction. ... The gustatory system is the sensory system that uses taste buds (or lingual papillae) on the upper surface of the tongue to provide information about the taste of food being eaten. ... The somatosensory system is the sensory system of somatic sensation. ... A nociceptor is a sensory receptor that responds only after a high level of stimuli or a level enough to hurt the individual. ... The vestibular system, or balance system, is the sensory system that provides the dominant input about our movement and orientation in space. ... A mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion. ... Pressure (symbol: p) is the force per unit area acting on a surface in a direction perpendicular to that surface. ... See Oscillator (disambiguation) for particular types of oscillation and oscillators. ... 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. ...