arm |
fly |
top 10 words in brain distribution (in article): muscle bone human animal structure nerve contain branch join limb |
top 10 words in brain distribution (in article): species bird egg produce insect body food time human family |
top 10 words in brain distribution (not in article): cell body form brain tissue organism wear function organ horse |
top 10 words in brain distribution (not in article): light fish water cell female drink form animal lamp live |
times more probable under arm 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under fly (words not in the model) | |
In anatomy, an arm'" is one of the upper limbs of an animal. The term "arm" can also be used for analogous structures, such as one of the paired upper limbs of a four-legged animal, or the arms of cephalopods. In the lexicon of human anatomy, the term "arm" refers specifically to the segment between the shoulder and the elbow. The segment between the elbow and wrist is the forearm. However, in colloquial speech the term "arm" often refers to the entire upper limb from shoulder to wrist. In primates the arms are richly adapted for both climbing and for more skilled, manipulative tasks. The ball and socket shoulder joint allows for movement of the arms in a wide circular plane, while the presence of two forearm bones which can rotate around each other allows for additional range of motion at this level. Anatomy of the human arm. The human arm contains 30 bones, joints, muscles, nerves, and blood vessels. Many of these muscles are used for everyday tasks. Bony structure and joints. The humerus is the (upper) arm bone. It joins with the scapula above at the shoulder joint (or glenohumeral joint) and with the ulna and radius below at the elbow joint. Elbow joint. The elbow joint is the hinge joint between the distal end of the humerus and the proximal ends of the radius and ulna. The humerus cannot be broken easily. Its strength allows it to handle loading up to 300lbs. Osteofascial compartments. The arm is divided by a fascial layer (known as lateral and medial intermuscular septa) separating the muscles into two "osteofascial compartments": The fascia merges with the periosteum (outer bone layer) of the humerus. The compartments contain muscles which are innervated by the same nerve and perform the same action. Two other muscles are considered to be partially in the arm: Cubital fossa. The cubital fossa is clinically important for venepuncture and for blood pressure measurement. It is an imaginary triangle with borders being: The structures which pass through the cubital fossa are vital. The order from which they pass into the forearm are as follows, from medial to lateral: Nerve supply. The musculocutaneous nerve, from C5, C6, C7, is the main supplier of muscles of the anterior compartment. It originates from the lateral cord of the brachial plexus of nerves. It pierces the coracobrachialis muscle and gives off branches to the muscle, as well as to brachialis and biceps brachii. It terminates as the anterior cutaneous nerve of the forearm. The radial nerve, which is from the fifth cervical spinal nerve to the first thoracic spinal nerve, originates as the continuation of the posterior cord of the brachial plexus. This nerve enters the lower triangular space (an imaginary space bounded by, amongst others, the shaft of the humerus and the triceps brachii) of the arm and lies deep to the triceps brachii. Here it travels with a deep artery of the arm (the profunda brachii), which sits in the radial groove of the humerus. This fact is very important clinically as a fracture of the bone at the shaft of the bone here can cause lesions or even transections in the nerve. Other nerves passing through give no supply to the arm. These include: Arteries. The main artery in the arm is the brachial artery. This artery is a continuation of the axillary artery. The point at which the axillary becomes the brachial is distal to the lower border of teres major. The brachial artery gives off an important branch, the profunda brachii (deep artery of the arm). This branching occurs just below the lower border of teres major. The brachial artery continues to the cubital fossa in the anterior compartment of the arm. It travels in a plane between the biceps and triceps muscles, the same as the median nerve and basilic vein. It is accompanied by venae comitantes (accompanying veins). It gives branches to the muscles of the anterior compartment. The artery is in between the median nerve and the tendon of the biceps muscle in the cubital fossa. It then continues into the forearm. The profunda brachii travels through the lower triangular space with the radial nerve. From here onwards it has an intimate relationship with the radial nerve. They are both found deep to the triceps muscle and are located on the spiral groove of the humerus. Therefore fracture of the bone may not only lead to lesion of the radial nerve, but also haematoma of the internal structures of the arm. The artery then continues on to anastamose with the recurrent radial branch of the brachial artery, providing a diffuse blood supply for the elbow joint. Veins. The veins of the arm carry blood from the extremities of the limb, as well as drain the arm itself. The two main veins are the basilic and the cephalic veins. There is a connecting vein between the two, the median cubital vein, which passes through the cubital fossa and is clinically important for venepuncture (withdrawing blood). The basilic vein travels on the medial side of the arm and terminates at the level of the seventh rib. The cephalic vein travels on the lateral side of the arm and terminates as the axillary vein. It passes through the deltopectoral triangle, | True flies'" are insects of the Order "'Diptera'" (=two, and "pteron"= wing), possessing a single pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax. The presence of a single pair of wings distinguishes true flies from other insects with "fly" in their name, such as mayflies, dragonflies, damselflies, stoneflies, whiteflies, fireflies, alderflies, dobsonflies, snakeflies, sawflies, caddisflies, butterflies or scorpionflies. Some true flies have become secondarily wingless, especially in the superfamily Hippoboscoidea, or among those that are inquilines in social insect colonies. Diptera is a large order, containing an estimated 240,000 species of mosquitos, gnats, midges and others, although under half of these (about 120,000 species) have been described. It is one of the major insect orders both in terms of ecological and human (medical and economic) importance. The Diptera, in particular the mosquitoes (Culicidae), are of great importance as disease transmitters, acting as vectors for malaria, dengue, West Nile virus, yellow fever, encephalitis and other infectious diseases. Classification. There are two generally accepted suborders of Diptera. The Nematocera are usually recognized by their elongated bodies and feathery antennae as represented by mosquitoes and crane flies. The Brachycera tend to have a more roundly proportioned body and very short antennae. A more recent classification has been proposed in which the Nematocera is split into two suborders, the Archidiptera and the Eudiptera, but this has not yet gained widespread acceptance among dipterists. Most of the Muscomorpha are further subdivided into the Acalyptratae and Calyptratae based on whether or not they have a calypter (a wing flap that extends over the halteres). Beyond that, considerable revision in the taxonomy of the flies has taken place since the introduction of modern cladistic techniques, and much remains uncertain. The secondary ranks between the suborders and the families are more out of practical or historical considerations than out of any strict respect for phylogenetic classifications (some modern cladists tend to spurn the use of Linnaean rank names). Nearly all classifications in use now, including this article, contain some paraphyletic groupings; this is emphasized where the numerous alternative systems are most greatly at odds. See list of families of Diptera. Dipterans belong to the group Mecopterida, that also contains Mecoptera, Siphonaptera, Lepidoptera (butterflies and moths) and Trichoptera. Inside it, they are sometimes classified closely together with Mecoptera and Siphonaptera in the superorder Antliophora. Evolution. Diptera are usually thought to derive from Mecoptera or a strictly related group. First true dipterans are known from the Middle Triassic, becoming widespread during the Middle and Late Triassic . Flies in culture. Flies have often been used in mythology and literature to represent agents of death and decay, such as the Biblical fourth plague of Egypt, or portrayed as nuisances (e.g., in Greek mythology, Myiagros was a god who chased away flies during the sacrifices to Zeus and Athena, and Zeus sent a fly to bite the horse Pegasus causing Bellerophon to fall back to Earth when he attempted to ride to Mount Olympus), though in a few cultures the connotation is not so negative (e.g., in the traditional Navajo religion, Big Fly is an important spirit being). Emily Dickinson's poem "I Heard a Fly Buzz When I Died" also makes reference to flies in the context of death. Not surprisingly, in art and entertainment, flies are also used primarily to introduce elements of horror or the simply mundane; an example of the former is the 1958 science fiction film "The Fly" (remade in 1986), in which a scientist accidentally exchanges parts of his body with those of a fly. Examples of the latter include trompe l'oeil paintings of the fifteenth century such as "Portrait of a Carthusian" by Petrus Christus, showing a fly sitting on a fake frame , a 2001 art project by Garnet Hertz in which a complete web server was implanted into a dead fly, and various musical works (such as Yoko Ono's album "Fly", U2's song "The Fly," Dave Matthews' song "The Fly" and Béla Bartók's "From the Diary of a Fly"). The ability of flies to cling to almost any surface has also inspired the title of "Human Fly" for stunt performers whose stunts involve climbing buildings, including both real life and fictional individuals. Aside from the fictional and conceptual role flies play in culture, there are practical roles that flies can play (e.g., flies are reared in large numbers in Japan to serve as pollinators of sunflowers in greenhouses), especially the maggots of various species. Maggots. Some types of maggots found on corpses can be of great use to forensic scientists. By their stage of development, these maggots can be used to give an indication of the time elapsed since death, as well as the place the organism died. Maggot species can be identified through the Use of DNA in forensic entomology. The size of the house fly maggot is 10–20 mm (⅜–¾ in). At the height of the summer season, a generation of flies (egg to adult) may be produced in 12–14 days. Other types of maggots are bred commercially, as a popular bait in angling, and a food for carnivorous pets such as reptiles or birds. Maggots have been used in medicine to clean out necrotic wounds , and in food production, particularly of cheeses (casu marzu). |