arm |
table |
top 10 words in brain distribution (in article): muscle human bone animal structure nerve contain branch join limb |
top 10 words in brain distribution (in article): material wood design size type paint shape metal century wall |
top 10 words in brain distribution (not in article): cell body form brain tissue organism function organ bacterium membrane |
top 10 words in brain distribution (not in article): tea form light build tooth plastic glass steel common construction |
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 table (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 | 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. |