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Infrared Sensing In Snakes
The ability to sense infrared thermal radiation evolved independently in two different groups of snakes, one consisting of the families Boidae (boas) and Pythonidae (pythons), the other of the family Crotalinae (pit vipers). What is commonly called a pit organ allows these animals to essentially "see" radiant heat at wavelengths between 5 and 30 μm. The more advanced infrared sense of pit vipers allows these animals to strike prey accurately even in the absence of light, and detect warm objects from several meters away. It was previously thought that the organs evolved primarily as prey detectors, but recent evidence suggests that it may also be used in thermoregulation and predator detection, making it a more general-purpose sensory organ than was supposed.Greene HW. 1992. The ecological and behavioral context for pitviper evolution. ''In'' Campbell JA, Brodie ED Jr. 1992. Biology of the Pitvipers. Texas: Selva. 467 pp. 17 plates. . Phylogeny and evolution The facial pit u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Pit Organs Of Two Different Snakes
''The'' () is a grammatical article in English, denoting persons or things already mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with pronouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of pronoun ''thee'') when followed by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diagram Of The Crotaline Pit Organ
A diagram is a symbolic representation of information using visualization techniques. Diagrams have been used since prehistoric times on walls of caves, but became more prevalent during the Enlightenment. Sometimes, the technique uses a three-dimensional visualization which is then projected onto a two-dimensional surface. The word ''graph'' is sometimes used as a synonym for diagram. Overview The term "diagram" in its commonly used sense can have a general or specific meaning: * ''visual information device'' : Like the term " illustration", "diagram" is used as a collective term standing for the whole class of technical genres, including graphs, technical drawings and tables. * ''specific kind of visual display'' : This is the genre that shows qualitative data with shapes that are connected by lines, arrows, or other visual links. In science the term is used in both ways. For example, Anderson (1997) stated more generally: "diagrams are pictorial, yet abstract, represe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warm-blooded
Warm-blooded is an informal term referring to animal species which can maintain a body temperature higher than their environment. In particular, homeothermic species maintain a stable body temperature by regulating metabolic processes. The only known living homeotherms are birds and mammals, and the only living homeothermic lizard is the Argentine black and white tegu. Some extinct reptiles such as ichthyosaurs, pterosaurs, plesiosaurs and some non-avian dinosaurs are believed to have been homeotherms. Other species have various degrees of thermoregulation. Animal body temperature control varies by species, so the terms "warm-blooded" and " cold-blooded" (though still in everyday use) suggest a false idea of there being only two categories of body temperature control, and are no longer used scientifically. Terminology In general, warm-bloodedness refers to three separate categories of thermoregulation. * Endothermy is the ability of some creatures to control their body t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolometer
A bolometer is a device for measuring radiant heat by means of a material having a temperature-dependent electrical resistance. It was invented in 1878 by the American astronomer Samuel Pierpont Langley. Principle of operation A bolometer consists of an absorptive element, such as a thin layer of metal, connected to a thermal reservoir (a body of constant temperature) through a thermal link. The result is that any radiation impinging on the absorptive element raises its temperature above that of the reservoir – the greater the absorbed power, the higher the temperature. The intrinsic thermal time constant, which sets the speed of the detector, is equal to the ratio of the heat capacity of the absorptive element to the thermal conductivity, thermal conductance between the absorptive element and the reservoir. The temperature change can be measured directly with an attached resistive thermometer, or the resistance of the absorptive element itself can be used as a thermometer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRPA1
Transient receptor potential cation channel, subfamily A, member 1, also known as transient receptor potential ankyrin 1, TRPA1, or The Wasabi Receptor, is a protein that in humans is encoded by the ''TRPA1'' (and in mice and rats by the ''Trpa1'') gene. TRPA1 is an ion channel located on the plasma membrane of many human and animal cells. This ion channel is best known as a sensor for pain, cold and itch in humans and other mammals, as well as a sensor for environmental irritants giving rise to other protective responses (tears, airway resistance, and cough). Function TRPA1 is a member of the transient receptor potential channel family. TRPA1 contains 14 N-terminal ankyrin repeats and is believed to function as a mechanical and chemical stress sensor. One of the specific functions of this protein studies involves a role in the detection, integration and initiation of pain signals in the peripheral nervous system. It can be activated at sites of tissue injury or sites of infl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transient Receptor Potential Channel
Transient receptor potential channels (TRP channels) are a group of ion channels located mostly on the plasma membrane of numerous animal cell types. Most of these are grouped into two broad groups: Group 1 includes TRPC ( "C" for canonical), TRPV ("V" for vanilloid), TRPVL ("VL" for vanilloid-like), TRPM ("M" for melastatin), TRPS ("S" for soromelastatin), TRPN ("N" for no mechanoreceptor potential C), and TRPA ("A" for ankyrin). Group 2 consists of TRPP ("P" for polycystic) and TRPML ("ML" for mucolipin). Other less-well categorized TRP channels exist, including yeast channels and a number of Group 1 and Group 2 channels present in non-animals. Many of these channels mediate a variety of sensations such as pain, temperature, different kinds of tastes, pressure, and vision. In the body, some TRP channels are thought to behave like microscopic thermometers and used in animals to sense hot or cold. Some TRP channels are activated by molecules found in spices like garlic (alli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Conduction
Conduction is the process by which heat is transferred from the hotter end to the colder end of an object. The ability of the object to conduct heat is known as its ''thermal conductivity'', and is denoted . Heat spontaneously flows along a temperature gradient (i.e. from a hotter body to a colder body). For example, heat is conducted from the hotplate of an electric stove to the bottom of a saucepan in contact with it. In the absence of an opposing external driving energy source, within a body or between bodies, temperature differences decay over time, and thermal equilibrium is approached, temperature becoming more uniform. In conduction, the heat flow is within and through the body itself. In contrast, in heat transfer by thermal radiation, the transfer is often between bodies, which may be separated spatially. Heat can also be transferred by a combination of conduction and radiation. In solids, conduction is mediated by the combination of vibrations and collisions of molec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinhole Camera
A pinhole camera is a simple camera without a lens but with a tiny aperture (the so-called '' pinhole'')—effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the camera obscura effect. The size of the images depends on the distance between the object and the pinhole. History Camera obscura The camera obscura or pinhole image is a natural optical phenomenon. Early known descriptions are found in the Chinese Mozi writings (circa 500 BCE) and the Aristotelian '' Problems'' (circa 300 BCE – 600 CE). Ibn al-Haytham (965–1039), an Arab physicist also known as Alhazen, described the camera obscura effect. Over the centuries others started to experiment with it, mainly in dark rooms with a small opening in shutters, mostly to study the nature of light and to safely watch solar eclipses. Giambattista Della Porta wrote in 1558 in his Magia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptive Field
The receptive field, or sensory space, is a delimited medium where some physiological stimuli can evoke a sensory neuronal response in specific organisms. Complexity of the receptive field ranges from the unidimensional chemical structure of odorants to the multidimensional spacetime of human visual field, through the bidimensional skin surface, being a receptive field for touch perception. Receptive fields can positively or negatively alter the membrane potential with or without affecting the rate of action potentials. A sensory space can be dependent of an animal's location. For a particular sound wave traveling in an appropriate transmission medium, by means of sound localization, an auditory space would amount to a reference system that continuously shifts as the animal moves (taking into consideration the space inside the ears as well). Conversely, receptive fields can be largely independent of the animal's location, as in the case of place cells. A sensory space can als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurons
A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. Non-animals like plants and fungi do not have nerve cells. Neurons are typically classified into three types based on their function. Sensory neurons respond to stimuli such as touch, sound, or light that affect the cells of the sensory organs, and they send signals to the spinal cord or brain. Motor neurons receive signals from the brain and spinal cord to control everything from muscle contractions to glandular output. Interneurons connect neurons to other neurons within the same region of the brain or spinal cord. When multiple neurons are connected together, they form what is called a neural circuit. A typical neuron consists of a cell body (soma), dendrites, and a single axon. The soma is a compact structure, and the axon an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges. Acoustics Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gasses, liquids, and solids including vibration, sound, ultrasound, and infrasound. A scientist who works in the field of acoustics is an ''acoustician'', while someone working in the field of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proprioceptive
Proprioception ( ), also referred to as kinaesthesia (or kinesthesia), is the sense of self-movement, force, and body position. It is sometimes described as the "sixth sense". Proprioception is mediated by proprioceptors, mechanosensory neurons located within muscles, tendons, and joints. Most animals possess multiple subtypes of proprioceptors, which detect distinct kinematic parameters, such as joint position, movement, and load. Although all mobile animals possess proprioceptors, the structure of the sensory organs can vary across species. Proprioceptive signals are transmitted to the central nervous system, where they are integrated with information from other sensory systems, such as the visual system and the vestibular system, to create an overall representation of body position, movement, and acceleration. In many animals, sensory feedback from proprioceptors is essential for stabilizing body posture and coordinating body movement. System overview In vertebrates, limb ve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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