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top 10 words in brain distribution (in article): form body muscle head human bone brain animal tissue allow |
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top 10 words in brain distribution (not in article): city love god animal state human female store word male |
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times more probable under hand 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under bed (words not in the model) | |
| The hands'" (med. /lat.: manus, pl. manūs) are the two intricate, prehensile, multi-fingered body parts normally located at the end of each arm of a human or other primate. They are the chief organs for physically manipulating the environment, using anywhere from the roughest motor skills (wielding a club) to the finest (threading a needle), and since the fingertips contain some of the densest areas of nerve endings on the human body, they are also the richest source of tactile feedback so that sense of touch is intimately associated with human hands. Like other paired organs (eyes, ears, legs), each hand is dominantly controlled by the opposing brain hemisphere, and thus handedness, or preferred hand choice for single-handed activities such as writing with a pen, reflects a significant individual trait. What constitutes a hand? Many mammals and other animals have grasping appendages similar in form to a hand such as paws, claws, and talons, but these are not scientifically considered to be hands. The scientific use of the term "hand" to distinguish the terminations of the front paws from the hind ones is an example of anthropomorphism. The only true hands appear in the mammalian order of primates. Hands must also have opposable thumbs, as described later in the text. Humans have only two hands (except in cases of polymelia), which are attached to the arms. Apes and monkeys are sometimes described as having four hands, because the toes are long and the hallux is opposable and looks more like a thumb, thus enabling the feet to be used as hands. Also, some apes have toes that are longer than human fingers. Anatomy of the human hand. The human hand consists of a broad palm (metacarpus) with 5 digits, attached to the forearm by a joint called the wrist (carpus). The back of the hand is formally called the dorsum of the hand. Digits. The four fingers on the hand are used for the outermost performance; these four digits can be folded over the palm which allows the grasping of objects. Each finger, starting with the one closest to the thumb, has a colloquial name to distinguish it from the others: The thumb (connected to the trapezium) is located on one of the sides, parallel to the arm. The thumb can be easily rotated 90°, on a level perpendicular to the palm, unlike the other fingers which can only be rotated approximately 45°. A reliable way of identifying true hands is from the presence of opposable thumbs. Opposable thumbs are identified by the ability to be brought opposite to the fingers, a muscle action known as opposition. Bones. The human hand has 27 bones: the carpus or wrist account for 8; the metacarpus or palm contains 5; the remaining 14 are digital bones; fingers and thumb. The eight bones of the wrist are arranged in two rows of four. These bones fit into a shallow socket formed by the bones of the forearm. The bones of proximal row are (from lateral to medial): scaphoid, lunate, triquetral and pisiform. The bones of the distal row are (from lateral to medial): trapezium, trapezoid, capitate and hamate. The palm has 5 bones (metacarpals), one to each of the 5 digits. These metacarpals have a head and a shaft. Human hands contain 14 digital bones, also called phalanges, or phalanx bones: 2 in the thumb (the thumb has no middle phalanx) and 3 in each of the four fingers. These are: Sesamoid bones are small ossified nodes embedded in the tendons to provide extra leverage and reduce pressure on the underlying tissue. Many exist around the palm at the bases of the digits; the exact number varies between different people. Articulations=== Also of note is that the articulation of the human hand is more complex and delicate than that of comparable organs in any other animals. Without this extra articulation, we would not be able to operate a wide variety of tools and devices. The hand can also form a fist, for example in combat, or as a gesture. Muscles and tendons. The movements of the human hand are accomplished by two sets of each of these tissues. They can be subdivided into two groups: the extrinsic and intrinsic muscle groups. The extrinsic muscle groups are the long flexors and extensors. They are called extrinsic because the muscle belly is located on the forearm. The intrinsic muscle groups are the thenar and hypothenar muscles (thenar referring to the thumb, hypothenar to the small finger), the interosseus muscles (between the metacarpal bones, four dorsally and three volarly) and the lumbrical muscles. These muscles arise from the deep flexor (and are special because they have no bony origin) and insert on the dorsal extensor hood mechanism. The fingers have two long flexors, located on the underside of the forearm. They insert by tendons to the phalanges of the fingers. The deep flexor attaches to the distal phalanx, and the superficial flexor attaches to the middle phalanx. The flexors allow for the actual bending of the fingers. The thumb has one long flexor and a short flexor in the thenar muscle group. The human thumb also has other muscles in the thenar group (opponens- and abductor muscle), moving the thumb in opposition, making grasping possible. The extensors are located on the back of the forearm and are connected in a more complex way than the flexors to the dorsum of the fingers. The tendons unite with the interosseous and lumbrical muscles to form the extensorhood mechanism. The primary function of the extensors is to straighten out the digits. The thumb has two extensors in the forearm; the tendons of these form the anatomical snuff box. Also, the index finger and the little finger have an extra extensor, used for instance for pointing. The extensors are situated within 6 separate compartments. The 1st compartment contains abductor pollicis longus and extensor pollicis brevis. The 2nd compartment contains extensors carpi radialis longus and brevis. The 3rd compartment contains extensor pollicis longus. The extensor digitorum indicis and extensor digititorum communis are within the 4th compartment. Extensor digiti minimi is in the fifth, and extensor carpi ulnaris is in the 6th. Variation. Some people have more than the usual number of fingers or toes, a condition called polydactyly. Others may have more than the typical number of metacarpal bones, a condition often caused by genetic disorders like Catel-Manzke syndrome. The average length of an adult male hand is 189 mm, while the average length of an adult female hand is 172 mm. The average hand breadth for adult males and females is 84 and 74 mm respectively. | A bed'" is a piece of furniture (or a location) used as a place to sleep, and as a primary place for relaxation and sexual intercourse. To make beds more comfortable, mattresses are usually placed on top of them. The second layer is the box spring Inner-sprung Base. The box spring or "divan" is a large mattress-sized box containing wood and springs that provide additional support and suspension for the mattress. The box spring will typically lie on a bed frame(which lifts the mattress mattress-box spring off the ground) or on slats (usually made of 2" x 4" wood). A "headboard", "side rails", and "footboard" or "front rail" will complete the bed. "Headboard only" beds often incorporate a "dust ruffle", "bed skirt", or "valance sheet" to hide the bed frame. For greater head support, most people use a pillow, placed at the top of a mattress. Also used is some form of covering blanket to insulate the sleeper, often bed sheets, a quilt, or a duvet. Also, some people prefer to dispense with the box spring and bed frame, and replace it with a platform bed style. This is more common in Europe and Japan. The Ancient World. Early beds were little more than piles of straw or some other natural materials. An important change was raising them off the ground, to avoid draughts, dirt, and pests. The Egyptians had high bedsteads which were ascended by steps, with bolsters or pillows, and curtains to hang round. The elite of Egyptian society such as its pharaohs and queens even had beds made of wood and gilded with gold. Often there was a head-rest as well, semi-cylindrical and made of stone, wood or metal. Assyrians, Medes and Persians had beds of a similar kind, and frequently decorated their furniture with inlays or appliqués of metal, mother-of-pearl and ivory. The oldest account of a bed is probably that of Odysseus: a charpoy woven of rope, plays a role in the Odyssey. A similar bed can be seen at the St Fagans National History Museum in Wales. Odysseus also gives an account of how he crafted the nuptial bed for himself and Penelope, out of an ancient, huge olive tree trunk that used to grow on the spot before the bridal chamber was built. His detailed description finally persuades the doubting Penelope that the shipwrecked, aged man is indeed her long-lost husband. Homer also mentions the inlaying of the woodwork of beds with gold, silver and ivory.The Greek bed had a wooden frame, with a board at the head and bands of hide laced across, upon which skins were placed. At a later period the bedstead was often veneered with expensive woods; sometimes it was of solid ivory veneered with tortoise-shell and with silver feet; often it was of bronze. The pillows and coverings also became more costly and beautiful; the most celebrated places for their manufacture were Miletus, Corinth and Carthage. Folding beds, too, appear in the vase paintings. The Roman mattresses were stuffed with reeds, hay, wool or feathers; the last was used towards the end of the Republic, when custom demanded luxury. Small cushions were placed at the head and sometimes at the back. The bedsteads were high and could only be ascended by the help of steps. They were often arranged for two persons, and had a board or railing at the back as well as the raised portion at the head. The counterpanes were sometimes very costly, generally purple embroidered with figures in gold; and rich hangings fell to the ground masking the front. The bedsteads themselves were often of bronze inlaid with silver, and Elagabalus had one of solid silver. In the walls of some of the houses at Pompeii bed niches are found which were probably closed by curtains or sliding partitions. Ancient Romans had various kinds of beds for repose. These included: Medieval Europe. The ancient Germans lay on the floor on beds of leaves covered with skins, or in a kind of shallow chest filled with leaves and moss. In the early middle ages they laid carpets on the floor or on a bench against the wall, placed upon them mattresses stuffed with feathers, wool or hair, and used skins as a covering. They appear to have generally lain naked in bed, wrapping themselves in the large linen sheets which were stretched over the cushions. In the 13th century luxury increased, and bedsteads were made of wood much decorated with inlaid, carved and painted ornament. They also used folding beds, which served as couches by day and had cushions covered with silk laid upon leather. At night a linen sheet was spread and pillows placed, while silk-covered skins served as coverlets. Curtains were hung from the ceiling or from an iron arm projecting from the wall. The Carolingian manuscripts show metal bedsteads much higher at the head than at the feet, and this shape continued in use until the 13th century in France, many cushions being added to raise the body to a sloping position. In the 12th-century manuscripts the bedsteads appear much richer, with inlays, carving and painting, and with embroidered coverlets and mattresses in harmony. Curtains were hung above the bed, and a small hanging lamp is often shown. In the 14th century the woodwork became of less importance, being generally entirely covered by hangings of rich materials. Silk, velvet and even cloth of gold were much used. Inventories from the beginning of the 14th century give details of these hangings lined with fur and richly embroidered. Then it was that the tester bed made its first appearance, the tester being slung from the ceiling or fastened to the walls, a form which developed later into a room within a room, shut in by double curtains, sometimes even so as to exclude all drafts. The space between bed and wall was called the "ruelle", and very intimate friends were received there. In the 15th century beds became very large, reaching to 7 or 8 feet by 6 or 7 feet. The mattresses were often filled with pea-shucks, straw or feathers. At this time great personages were in the habit of carrying most of their property about with them, including beds and bed-hangings, and for this reason the bedsteads were for the most part mere frameworks to be covered up; but about the beginning of the 16th century bedsteads were made lighter and more decorative, since the lords remained in the same place for longer periods. Renaissance and Modern Europe. In the 17th century, which has been called "the century of magnificent beds," the style "a la duchesse", with tester and curtains only at the head, replaced the more enclosed beds in France, though they lasted much longer in England. Louis XIV had an enormous number of sumptuous beds, as many as 413 being described in the inventories of his palaces. Some of them had embroideries enriched with pearls, and figures on a silver or golden ground. The great bed at Versailles had crimson velvet curtains on which "The Triumph of Venus" was embroidered. So much gold was used that the velvet scarcely showed. In the 18th century feather pillows were first used as coverings in Germany, which in the fashions of the bed and the curious etiquette connected with the bedchamber followed France for the most part. The beds were "a la duchesse", but in France itself there was great variety both of name and shape. The custom of the "bed of justice" upon which the king of France reclined when he was present in parliament, the princes being seated, the great officials standing, and the lesser officials kneeling, was held to denote the royal power even more than the throne. Louis XI is credited with its first use, and the custom lasted till the end of the monarchy. In the "chambre de parade", where the ceremonial bed was placed, certain persons, such as ambassadors or great lords, whom it was desired to honour, were received in a more intimate fashion than the crowd of courtiers. At Versailles women received their friends in their beds, both before and after childbirth, during periods of mourning, and even directly after marriage; in fact in any circumstances which were thought deserving of congratulation or condolence. During the 17th century this curious custom became general, perhaps to avoid the tiresome details of etiquette. Portable beds were used in high society in France till the end of the "ancien regime". The earliest of which mention has been found belonged to Charles the Bold. They had curtains over a light framework, and were in their way as fine as the stationary beds. Iron beds appear in the 18th century; the advertisements recommend them as free from the insects which sometimes infested wooden bedsteads. Elsewhere, there was also the closed bed with sliding or folding shutters, and in England, where beds were commonly quite simple in form, the four poster was the usual citizen's bed until the middle of the 19th century. Bed sizes. Beds come in a wide array of shapes and sizes. Most countries have a standard set of four sizes of mattresses. While the "Double" size appears to be standard among English speaking countries, based on the imperial measurement of 4 ft 6 in by 6 ft 3 in, the sizes for other bed types tend to vary. The European sizes differ; they are based on the metric system. A king-sized bed differs from the other sizes in implementation, as it is not common to have a king-sized box spring; rather, two smaller box-springs are used under a king-sized mattress. It is a common misconception that on a U.S. "Standard" or "Eastern King", the box springs are identical in size to a "Twin Extra-Long," however "Twin Extra-Long" mattresses next to each other add up to 78 inches wide instead of the 76 inch width that is standard for an "Eastern King." Standard sizes. Modern manufacturing conventions have resulted in a limited number of standard sizes of commercial bedding for mattresses and box springs. They vary by country of origin. The sizes in the UK and Ireland, other than the "Double", vary compared to the U.S. sizes, being generally smaller. The U.S. "Queen" corresponds to UK "King" and "King" to "Super King". The European or continental basic sizes are similar to the UK but have a set length of 2 metres. The denominations Queen, King and Super King are not used in continental Europe, and "Double" refers to 140cm or any higher width. Instead of these US UK denominations, the bed width is given in centimetres. These dimensions are for the mattress—the actual bed frame will be a little bigger in order to fully encompass and support the mattress. The thickness of the mattress may vary considerably. Other European sizes. Modern continental Europe practice is to refer to a bed by explicit width or size ("80 cm bed" or "80x200 cm bed"). Other sizes found include: In France, Spain and Mexico, the length of older beds is sometimes 1.9 metres instead of 2 metres. Most mattress sizes in the Netherlands are also available in extra long, meaning 2.2 m instead of 2.0 m. In the Scandinavian countries, standards vary from one country to another. In Norway, these sizes are used: Small single: 0.75 x 2m (30 x 79 inches) Single: 0.90 x 2m (35.5 x 79 inches) Large Single: 1.2m x 2m (47 x 79 inches) Queen: 1.50 x 2m (60 x 79 inches, equal to two small single mattresses) King: 1.80 x 2m (71 x 79 inches, equal to two single mattresses) Beds mattresses are often available also in "extra long" (2.2m or 86.6 inches length). Some older beds are only 1.9m (75 inches) long, while antique beds often are even shorter (since they in older times often slept in a reclined position rather than the close to supine position which is common today). Other New Zealand sizes. The following bed sizes are available in New Zealand: Types of beds. There are many varieties of beds: Bed frames. Bed frames, also called bed steads, are made of wood or metal. The frame is made up of head, foot, and side rails. For heavy duty or larger frames (such as for queen- and king-sized beds), the bed frame also includes a center support rail. These rails are assembled to create a box for the mattress or mattress box spring to sit on. Though not truly parts of a bed frame, many people include headboards, footboards, and bed rails in their definition of bed frames. Headboards and footboards can be wood or metal. They can be stained, painted, or covered in fabric or leather. Bed rails are made of wood or metal and are attached to a headboard and footboard. Wooden slats are placed perpendicular to the bed rails to support the mattress mattress box spring. Bed rails and frames are often attached to the bed post using knock-down fittings. A knock-down fitting enables the bed to be easily dismantled for removal. Primary knock-down fittings for bed rails are as follows: Safety rails can be added to the sides of a bed (normally a children's bed) to stop anyone falling out of the sides of the bed. A safety rail is normally a piece of wood that attaches to the side rails on one or both sides of the bed. They are made so that they can be easily removed when no longer required. |