hand |
lettuce |
top 10 words in brain distribution (in article): form body head muscle allow human bone hand animal brain |
top 10 words in brain distribution (in article): species plant century form type food water produce world family |
top 10 words in brain distribution (not in article): cell fuel engine energy wear gas iron horse blade produce |
top 10 words in brain distribution (not in article): wear horse bird egg woman clothe time fish saddle female |
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 lettuce (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 | Lettuce'" ("Lactuca sativa") is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. In many countries, it is typically eaten cold, raw, in salads, hamburgers, tacos, and in many other dishes. In some places, including China, lettuce is typically eaten cooked and use of the stem is as important as use of the leaf. Both the English name and the Latin name of the genus are ultimately derived from "lac", the Latin word for “milk”, referring to the plant’s milky juice. Mild in flavour, it has been described over the centuries as a cooling counterbalance to other ingredients in a salad. In his humorous essay "100 Things I chew", filmmaker John Waters refers to iceberg lettuce as "the polyester of greens". Description. The lettuce plant has a short stem initially (a rosette growth habit), but when it blooms, the stem lengthens, branches, and produces many flower heads that look like those of dandelions, but smaller. This is referred to as bolting. When grown to eat, lettuce is harvested before it bolts. Lettuce is used as a food plant by the larvae of some Lepidoptera. The largest lettuce head, of the Salad Bowl cultivar, weighed 11 kg (25 lb) grown by Colin Bowcock of Willaston, England, in 1974. Cultivation. Lettuce is grown commercially worldwide, hardy to Zone 6, requiring light, sandy, humus rich, moist soil. It dislikes dry conditions and can cause plants to bolt (go to seed). Early and late sowing in sunny positions or summer crops in shade. It is considered fairly easy to grow and a suitable crop for beginners. "Planting Depth:" Some resources suggest planting seeds by covering lightly with soil while others suggest a depth of 1 4 to 1 2 inch "Planting Spacing:" Thin seedlings to 10 cm (4 in) apart for leaf lettuce [1 sq. m (9 sq ft)] and 6 to 8 inches apart for Cos or Butterhead (4 sq ft 1 sq ft), transplant Crisphead seedlings 10 to 12 inches apart in the row (1 sq ft). "Row Spacing:" 12 18 inches apart History. The earliest depiction of lettuce is in the carvings at the temple of Senusret I at Karnak, where he offers milk to the god Min, to whom the lettuces was sacred. Lettuce was considered an aphrodisiac food in Ancient Egypt, and appears as such in "The Contendings of Horus and Seth". Later, Ancient Greek physicians believed lettuce could act as a sleep-inducing agent. The Romans cultivated it, and it eventually made its way to France cultivated of the Papal Court at Avignon. Christopher Columbus introduced lettuce to the new world. Cultivars. There are six commonly recognised Cultivar Groups of lettuce which are ordered here by head formation and leaf structure; there are hundreds of cultivars of lettuce selected for leaf shape and colour, as well as extended field and shelf life, within each of these Cultivar Groups: Some lettuces (especially iceberg) have been specifically bred to remove the bitterness from their leaves. These lettuces have a high water content with very little nutrient value. The more bitter lettuces and the ones with pigmented leaves contain antioxidants. Breeding. "L. sativa" can easily be bred with closely related species in "Lactuca" such as "L. serriola", "L. saligna", and "L. virosa", and breeding programs for cultivated lettuce have included those species to broaden the available gene pool. Starting in the 1990s, such programs began to include more distantly related species such as "L. tatarica". Seed Saving. Inbreeding plant, flowers form in heads of 10-25 individual florets of perfect flowers. Considered suitable for seed-saving beginners Production. The Food and Agriculture Organization of the United Nations reports that world production of lettuce and chicory for calendar year 2007 was 23.55 million tons, primarily coming from China(51%), United States(22%) and Spain(5%). Nutrition. Lettuce is a fat free, low calorie food. It is a valuable source of vitamin A and folic acid. Lactucarium (or “Lettuce Opium”) is a mild opiate-like substance that is contained in all types of lettuce. Both the Romans and Egyptians took advantage of this property eating lettuce at the end of a meal to induce sleep. Religious restrictions. The Yazidi of northern Iraq consider eating lettuce taboo. |