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Yawn
A yawn is a reflex in vertebrate animals characterized by a long inspiratory phase with gradual mouth gaping, followed by a brief climax (or acme) with muscle stretching, and a rapid expiratory phase with muscle relaxation, which typically lasts a few seconds. For fish and birds, this is described as gradual mouth gaping, staying open for at least three seconds and subsequently a rapid closure of the mouth. Almost all vertebrate animals, including mammals, birds, reptiles, amphibians, and even fish, experience yawning. The study of yawning is called chasmology. Yawning (oscitation) most often occurs in adults immediately before and after sleep, during tedious activities and as a result of its contagious quality. It is commonly associated with tiredness, stress, sleepiness, boredom, or even hunger. In humans, yawning is often triggered by the perception that others are yawning (for example, seeing a person yawning, or talking to someone on the phone who is yawning). This is a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exhalation
Exhalation (or expiration) is the flow of the breathing, breath out of an organism. In animals, it is the movement of air from the lungs out of the airways, to the external environment during breathing. This happens due to elastic properties of the lungs, as well as the internal intercostal muscles which lower the rib cage and decrease thoracic volume. As the thoracic diaphragm relaxes during exhalation it causes the tissue it has depressed to rise superiorly and put pressure on the lungs to expel the air. During Hyperpnea, forced exhalation, as when blowing out a candle, expiratory muscles including the abdominal muscles and internal intercostal muscles generate abdominal and thoracic pressure, which forces air out of the lungs. Exhaled air is 4% carbon dioxide, a waste product of cellular respiration during the production of energy, which is stored as Adenosine triphosphate, ATP. Exhalation has a complementary relationship to inhalation which together make up the respirator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaos (mythology)
Chaos () is the cosmological void state preceding the creation of the universe (the cosmos) in early Greek cosmology. It can also refer to an early state of the cosmos constituted of nothing but undifferentiated and indistinguishable matter. Etymology Greek ''kháos'' () means ' emptiness, vast void, chasm, abyss', related to the verbs ''kháskō'' () and ''khaínō'' () 'gape, be wide open', from Proto-Indo-European ', cognate to Old English ''geanian'', 'to gape', whence English '' yawn''. It may also mean space, the expanse of air, the nether abyss, or infinite darkness. Pherecydes of Syros (fl. 6th century BC) interprets ''chaos'' as water, like something formless that can be differentiated. Greco-Roman tradition Hesiod and the pre-Socratics use the Greek term in the context of cosmogony. Hesiod's Chaos has been interpreted as either "the gaping void above the Earth created when Earth and Sky are separated from their primordial unity" or "the gaping space below the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ginnungagap
In Norse mythology, Ginnungagap (old Norse: ; "gaping abyss", "yawning void") is the primordial, magical void mentioned in three poems from the ''Poetic Edda'' and the ''Gylfaginning'', the Eddaic text recording Norse cosmogony. Etymology ''Ginnunga-'' is usually interpreted as deriving from a verb meaning "gape" or "yawn", but no such word occurs in Old Norse except in verse 3 of the Eddic poem " Vǫluspá", "''gap var ginnunga''", which may be a play on the term. In her edition of the poem, Ursula Dronke suggested it was borrowed from Old High German ''ginunga'', as the term Múspell is believed to have been borrowed from Old High German. An alternative etymology links the ''ginn-'' prefix with that found in terms with a sacral meaning, such as ''ginn-heilagr'', ''ginn-regin'' (both referring to the gods) and ''ginn-runa'' (referring to the runes), thus interpreting ''Ginnungagap'' as signifying a "magical (and creative) power-filled space".De Vries (1977:167); cf. also Dillm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echopraxia
Echopraxia (also known as echokinesis) is the involuntary repetition or imitation of another person's actions. Similar to echolalia, the involuntary repetition of sounds and language, it is one of the echophenomena ("automatic imitative actions without explicit awareness"). It has long been recognized as a core feature of Tourette syndrome, and is considered a complex tic, but it also occurs in autism spectrum disorders, schizophrenia and catatonia, aphasia, and disorders involving the startle reflex such as latah. Echopraxia has also been observed in individuals with epilepsy, dementia and autoimmune disorders; the causes of and the link between echopraxia and these disorders is undetermined. The etymology of the term is from Ancient Greek: " ἠχώ (ēkhō) from ἠχή (ēkhē "sound") and " πρᾶξις (praksis, "action, activity, practice)". Characteristics Echopraxia is the involuntary mirroring of an observed action. Imitated actions can range from simple motor t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tensor Tympani Muscle
The tensor tympani is a muscle within the middle ear, located in the bony canal above the bony part of the auditory tube, and connects to the malleus bone. Its role is to dampen loud sounds, such as those produced from chewing, shouting, or thunder. Because its reaction time is not fast enough, the muscle cannot protect against hearing damage caused by sudden loud sounds, like explosions or gunshots, however some individuals have voluntary control over the muscle, and may tense it pre-emptively. Structure The tensor tympani is a muscle that is present in the middle ear. It arises from the cartilaginous part of the auditory tube, and the adjacent great wing of the sphenoid. It then passes through its own canal, and ends in the tympanic cavity as a slim tendon that connects to the handle of the malleus. The tendon makes a sharp bend around the ''processus cochleariformis'', part of the wall of its cavity, before it joins with the malleus. The tensor tympani receives blood from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive Feedback
Positive feedback (exacerbating feedback, self-reinforcing feedback) is a process that occurs in a feedback loop where the outcome of a process reinforces the inciting process to build momentum. As such, these forces can exacerbate the effects of a small disturbance. That is, the effects of a perturbation on a system include an increase in the magnitude of the perturbation. That is, ''A produces more of B which in turn produces more of A''.Keesing, R.M. (1981). Cultural anthropology: A contemporary perspective (2nd ed.) p.149. Sydney: Holt, Rinehard & Winston, Inc. In contrast, a system in which the results of a change act to reduce or counteract it has negative feedback. Both concepts play an important role in science and engineering, including biology, chemistry, and cybernetics. Mathematically, positive feedback is defined as a positive loop gain around a closed loop of cause and effect. That is, positive feedback is Phase (waves), in phase with the input, in the sense that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chasm
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake. The axis of the rift area may contain volcanic rocks, and active volcanism is a part of many, but not all, active rift systems. Major rifts occur along the central axis of most mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates. ''Failed rifts'' are the result of continental rifting that failed to continue to the point of break-up. Typically the transition from rifting to spreading develops at a triple junction where three converging rifts meet over a hotspot. Two of these evolve to the point o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
