hand |
table |
top 10 words in brain distribution (in article): form body head muscle human brain bone tissue animal hand |
top 10 words in brain distribution (in article): material wood type design size wall surface paint shape floor |
top 10 words in brain distribution (not in article): cell fuel engine energy iron gas blade produce power steel |
top 10 words in brain distribution (not in article): cell form structure light body build produce process muscle drink |
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 table (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 | A table'" is a item of furniture comprising a surface supported by a base or legs. It may be used to hold articles such as food at a convenient or comfortable height when sitting, and is therefore often used in conjunction with chairs. Unlike many earlier table designs, most modern tables do not have drawers, although they are not uncommon. A table specifically intended for writing and office work is a desk, which may incorporate one or more drawers in the base. Some tables have removable sections or "leaves" used to extend the surface, or utilise hinged extensions of the table top known as "drop leaves". Etymology. The term "table" is derived from a merger of French "table" and Old English "tabele", ultimately from the Latin word "tabula", "a board, plank, flat top piece". In Late Latin, "tabula" took over the meaning previously reserved to "mensa" (preserved in Spanish "mesa" "table"). In Old English, the word replaced "bord" for this meaning. Shape, height, and function. Tables come in a wide variety of shapes, height, and materials, depending on their origin, style, and intended use. All tables are composed of a flat surface and a base with one or more supports, or legs. A table with a single, central foot is a pedestal table. Tables can be freestanding or designed for placement against a wall (a console table). Table tops can be in virtually any shape, although rectangular, square, round (e.g., the round table), and oval tops are the most frequent. Long tables often have extra legs for support. Others have higher surfaces for personal use while either standing or sitting on a tall stool. Many tables have tops that can be adjusted to change their position or size, either with foldable extensions or sliding parts that can alter the shape of the top. Some tables are entirely foldable for easy transport, e.g., camping. Small tables in trains and aircraft may be fixed or foldable, although many are simply convenient shelves rather than tables. Types of table. Tables of various shapes and sizes are designed for specific uses: Historically, various types of tables have been popular for other uses: History. Some very early tables were made and used by the Egyptians, and were little more than metal or stone platforms used to keep objects off the floor. They were not used for seating people. Food was put on large plates deposed on a pedestal for eating. The Egyptians made use of various small tables and elevated playing boards. The Chinese also created very early tables in order to pursue the arts of writing and painting. The Greeks and Romans made more frequent use of tables, notably for eating, although Greek tables were pushed under a bed after use. The Greeks invented a piece of furniture very similar to the guéridon. Tables were made of marble or wood and metal (typically bronze or silver alloys). Later, the larger rectangular tables were made of separate platforms and pillars. The Romans also introduced a large, semicircular table to Italy, the "mensa lunata". Furniture during the Middle Ages is not as well-known as that of earlier or later periods, and most sources show the types used by the nobility. In the Eastern Roman Empire, tables were made of metal or wood, usually with four feet and frequently linked by x-shaped stretchers. Tables for eating were large and often round or semicircular. A combination of a small round table and a lectern seemed very popular as a writing table. In western Europe, the invasions and internecine wars caused most of the knowledge inherited from the classical era to be lost. As a result of the necessary movability, most tables were simple trestle tables, although small round tables made from joinery reappeared during the 15th century and onward. In the Gothic era, the chest (furniture) became widespread and was often used as a table. Refectory tables first appeared at least as early as the 16th century, as an evolution of the trestle table; these tables were typically quite long and capable of supporting a sizeable banquet in the great hall or other reception room of a castle. |