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a. the evacuation of the bowels
b. the matter evacuated
2. Music a principal self-contained section of a symphony, sonata, etc., usually having its own structure
3. tempo or pace, as in music or literature
4. Fine arts the appearance of motion in painting, sculpture, etc.
5. Prosody the rhythmic structure of verse
6. Commerce a change in the market price of a security or commodity
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



(in biology), one of the manifestations of vital activity.

Animals and man. Movements enable an organism to interact actively with the environment—specifically, to move from place to place and to capture food. Movements are effected by specialized organs, the structure of which varies with the type of animal and depends on the type of locomotion and the nature of the habitat—terrestrial, aquatic, or aerial. The organs may be pseudopodia (the slow flow from one place to another of protoplasm; ameboid movement), cilia and flagella (ciliary and flagellar movement), or special body appendages by means of which the animals cling to a rough area of the substrate (setae, squamellae, scutella) or attach themselves to it (suckers). The most common construction of the locomotor organs, the limb, is a system of levers activated by muscular contractions. Some aquatic animals, such as sponges and corals, which maintain a sedentary mode of life, use cilia and flagella to set their immediate environment in motion and bring them food.

Animals can move about by (1) moving over a substrate, that is, upon solid or liquid support (walking, running, jumping, creeping, sliding), (2) moving freely in water (swimming), and (3) moving freely in air (flying). In all cases, the movements are the result of the interaction of forces external to the organism (gravity, environmental resistance) and internal forces (muscular tension, contraction of myofibrils, movements of protoplasm). Purposeful movements are possible only through the coordinated work of a large number of muscles, which is effected by the nervous system. Movements in water and air can also be passive. For example, certain spiders release their silk and are borne through great distances by the air currents. The soaring of birds, using air currents, is also a form of passive movement. Some aquatic animals have adaptations that maintain their bodies in a suspended state (for example, vacuoles in the external layer of protoplasm in radiolarians and air sacs in colonies of siphonophores). Active movements in water are accomplished by specialized remigial structures (from hairs and flagella to the modified limbs of aquatic turtles, birds, and seals), by flexure of the entire body (most fish, caudate amphibians), and by jet action, ejecting water from body cavities (medusoids and cephalopods). Active movement in air—flying—is characteristic of most insects, birds, and some mammals (bats). The movements in air of so-called flying fish, frogs, and mammals (for example, the flying squirrels) are not in fact flying but rather long, gliding jumps accomplished by means of such devices of support as elongated thoracic fins, interdigital membranes on the feet, and skin folds.

As animals evolved, the kinds of movement changed and became more complex. C. Darwin showed that in the course of evolution it was those kinds of movement and locomotor design that were vital and useful for the species that became fixed by natural selection. An important stage in the process was the development in vertebrates of the rigid skeleton and striated musculature. This entailed greater complexity in the structure of the nervous system and permitted a variety of movements, broadening the vital possibilities of the organisms.

In man, movements are the most important means of interacting with the environment and of influencing it actively, and they are highly varied: there are movements associated with the autonomic functions as well as with locomotion and the movements involved in work, everyday life, sports, speech, and writing. According to I. M. Sechenov, “all external manifestations of cerebral activity can in effect be reduced to muscular movement” (Izbr. proizv., 1953, p. 33).

There are two approaches to the study of animal and human movements. The first is the clarification of the biomechanical characteristics of the motor and support apparatus and a dynamic kinematic description of natural movements. The second (neurophysiological) approach studies the patterns of control of movements by the nervous system. The muscles that bring about movements have been found to be controlled reflexively by impulses from the central nervous system. The principal locomotor movements are inherited (unconditioned reflexes) and develop during the course of individual development (ontogeny) and as a result of constant exercise. The mastery of new movements is a complex process involving the formation of new conditioned-reflex connections and stabilizing them. After many repetitions voluntary movements are executed in a more coordinated and economical manner, and gradually they become automatic. Signals reaching the nervous system from proprioreceptors in the muscles, tendons, and joints are the most important factor in regulating movements. The proprioreceptors communicate information about the direction, magnitude, and speed of movements and activate reflex arcs in different parts of the nervous system whose interaction coordinates movements.

Plants. There are two basic types of movement in plants— passive and active. Passive, or hygroscopic, movements are caused by changes in the water content of the colloids that make up the cell membrane. In flowering plants, hygroscopic movements play an important role in spreading seeds and fruits. In the Jericho rose, a plant growing in the Arabian desert, the twigs are convolute when the air is dry but unfold when it is damp, break away from the substrate, and are borne off by the wind. Feathergrass and geranium fruits become buried in the ground because of hygroscopicity. In the Siberian pea tree the ripe pod dries out, two of its glumes become coiled into a spiral, and the seeds are forcibly scattered. Active movements are based mainly on the phenomena of irritability and the contractility of the proteins in plant cytoplasm and on the growth processes. Sensing the environment, plants react with intensified metabolic activity, acceleration of cytoplasmic movements, growth, and other movements. The stimulation perceived by the plant is transmitted along cytoplasmatic strands (plasmodesmata), after which the plant as a whole reacts to the stimulus. Weak stimulation intensifies, while strong irritation inhibits, the physiological processes. Active movements may be slow (as in growth) or quick (as in contractile movements). Growth movements include tropisms (the stimulation acts in a particular direction and there is unilateral growth, causing the organ to bend, such as in geotropism, phototropism, and chemotropism) and nastic movements (plant responses to stimuli in no single direction, such as in thermonasty and photonasty).

Contractile movements are often called turgor movements. These movements result from the interaction of adenosine triphosphate (ATP) and contractile proteins. Thus, the mechanism of contractile movements in plants is almost the same as that in the contraction of human muscle, the movements of slime mold, or the zoospores of algae. Active contractile movements include the spatial shifting of certain lower organisms—taxes—which, like tropisms, are caused by unilateral stimulation. Flagellate bacteria, some algae, and the antherozoids of mosses and ferns can react with taxis. Many algae (Chlamydomonadaceae) exhibit positive photo-taxis; the antherozoids of mosses collect in capillaries containing a weak sucrose solution, and those of ferns, in malic acid solution (chemotaxis). Seismonasty is a contractile movement probably caused by the contractions of cytoplasmic protein. Autonomous movements are similar to seis-monasties. For example, in the Indian telegraph plant (Des-modium gyrans) the compound leaf consists of a large blade and two smaller lateral blades that rise and fall like a semaphore. Under unfavorable conditions, such as darkness, these movements cease. In Biophytum sensitivum the leaflets fold up after strong stimulation, as in the mimosa, performing a number of rhythmic contractions. Apparently there is a breakdown and rapid restoration of ATP during this activity, which also causes leaves to move continuously under the influence of stimuli. The leaflets of the wood sorrel fold up in response to strong light, darkness, and elevation of temperature. They fold up toward evening and open again by night, apparently after the bond between the ATP and the contractile proteins is restored. ATP activity is high in plants capable of making nyctinastic (Acacia dealbata), seismonastic (Mimosa pudica), and autonomous (Desmodium gyrans) movements, but it is insignificant in plants that are incapable of movement (Desmodium canadensis). The ATP content is highest in tissues involved in the movements. The movements of mimosa leaves were once thought to be associated with a loss of turgor and an escape of water into the intercellular spaces in the leaf nodes. V. A. Engel’gardt (1957) has suggested that ATP participates in the osmotic phenomena associated with the movements of mimosa leaves and with the dehydration of its cells in the nodes.



Darwin, C. “Sposobnost’ k dvizheniiu u rastenii.” Soch., vol. 8. Moscow-Leningrad, 1941.
Zenkevich, L. A. “Ocherki po evoliutsii dvigatel’nogo apparata zhivotnykh.” Zhurnal obshchei biologii, 1944, vol. 5, no. 3.
Engel’gardt, V. A. “Khemicheskiye osnovy dvigatel’noi funktsii kletok i tkanei.” Vestnik AN SSSR, 1957, no. 11, p. 58.
Kalmykov, K. F. “Issledovaniia iavlenii razdrazhimosti rastenii ν russkoi nauke vtoroi poloviny 19 v.” Tr. In-ta istorii estestvoznaniia i tekhniki AN SSSR, 1960, vol. 32, issue 7.
Magnus, R. Ustanovka tela. Moscow-Leningrad, 1962. (Translated from German.)
Liubimova, M. N. “K kharakteristike dvigatel’noi sistemy rastenii Mimosa pudica.” In Mólekuliarnaia biologiia: Problemy i perspektivy. Moscow, 1964.
Poglazov, B. F. Struktura i funktsii sokratitel’nykh belkov. Moscow, 1965.
Bernshtein, N. A. Ocherki po fiziologii dvizhenii i fiziologii aktivnosti. Moscow, 1966.
Sukhanov, V. B. “Materialy po lokomotsii pozvonochnykh.” Biulleten’ Moskovskogo ob-va ispytateleiprirody, 1967, vol. 72, issue 2.
Alexander, R. Biomekhanika. Moscow, 1970. (Translated from English.)
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


In wood, same as working.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
Student preference, instrument location, type of movement, and musical feedback are all considerations for music professionals striving to increase a student's purposeful movement through playing musical instruments.
The two techniques are the group formation enforcement and the group purposeful movement. Both two techniques are simple, but effective in extending the reachability of the group, and they can be integrated into some existing DTN routing scheme under group mobility to expedite the packet delivery.
Integration of Purposeful Movement in Science Classrooms
In conclusion, this analysis has shown that less than half of 'purposeful movement' is performed in a forward direction, players perform the different types of movement with a range of intensities and players perform frequent turns during movement patterns.
The use of a switch may promote purposeful movement and set a foundation for a possible communication system.
Her purposeful movements do not yield the same results that a nondisabled child would experience.
Physicians at the University of Cincinnati Medical Center, where he died, said last Thursday that Warmbier showed no sign of understanding language or awareness of his surroundings, and had made no "purposeful movements or behaviours," though he was breathing on his own.
Before Mandelbrot, some economists claimed daily price moves could be divided into ordinary random movements (in the quiet periods) and larger purposeful movements "traceable to well-determined causes" (the wild periods).
Scheller) Criteria Score Jaw Relaxation Jaw freely mobile & relaxed 1 Jaw partially mobile 2 Jaw Immobile 3 Mask Ventilation Mask ventilation easy 1 Mask ventilation difficult 2 Mask ventilation impossible 3 Exposure of Vocal cords Vocal cords and arytenoids completely visible 1 Vocal cords and arytenoids partly visible 2 Vocal cords and arytenoids not visible 3 Position of Vocal cords Vocal cords open 1 Vocal cords mid position 2 Vocal cords closed 3 Cough/Movements after intubation No movements 1 One or two coughs 2 Persistent coughing 3 Purposeful movements 4 Tracheal intubation without additional drugs given Yes No Comparison of Jaw Mobility Criteria and score Group I Group II (Jaw mobility) (Fentanyl 2 mcg/kg) (Fentanyl 3 mcg/kg) Out of 50 no.
It is the term used when someone finds it difficult to carry out and coordinate skilled, purposeful movements and gestures with normal accuracy.
(See this article at to view a video of a patient with tics.) Simple motor tics are focal movements involving 1 group of muscles, whereas complex tics are sequential patterns of movement that involve >1 muscle group or resemble purposeful movements (Table 2).
A person who is sleepwalking walks and does other seemingly purposeful movements in a state of partial awakening from deep sleep.