The gorilla (Troglodytes Gorilla) is the largest anthropoid ape attaining a height of about 5.5 feet and is found in west Africa. Although a gentle and vegetarian animal, myths prevailed from the mid- 19th century until the mid-20th century of it attacking and eating the natives.
The erect position is more readily assumed by the gorilla than by most of the other anthropoid apes, owing to the shape of the sole of the foot, which is not inverted, and is shorter and broader;
but the ordinary gait is on all-fours. It has a ferocious-looking cast of features, due to the prognathism of the jaws, the extremely prominent supra-orbital ridges, and retreating forehead. Gorillas make a sleeping-place somewhat like a hammock, connecting the branches of a tree by means of the long, tough, slender stems of climbing plants, and lining it with dried fronds of palms or long grass. This abode is constructed at different heights from the ground, but there is never more than one such nest in a tree. The gorilla, like the chimpanzee, has thirteen ribs, whereas man and the orang have twelve. The gorilla and chimpanzee also have eight bones in the carpus or wrist, while the others have nine. The bones of the arm are much longer than in man, and the upper arm is longer than the forearm; the leg bones are shorter than in man. In the proportion of its molar teeth to the incisors and in the form of its pelvis it approaches somewhat closely the human form. The Phoenician navigator Hanno found the name in use in the 5th century BC in West Africa. Research Gorilla
The orang utan (Simia satyrus) is an anthropoid ape found only in Borneo and Sumatra, where its popular name means 'man of the woods'. The orang utan has very long arms, which reach to the ankle when the animal stands upright, and short, thick, twisted legs with a feebly developed calf, and narrow flat heels. The hair is very long, and is reddish orange in colour. The skull is without the prominent superciliary ridges of the gorilla, and is produced at the vertex, so as to give the animal the appearance of possessing a much elongated forehead. The central bone of the carpus, absent in man, the chimpanzee and the gorilla, is present in the orang utan. The great toe is very small and devoid of a nail in the adult, and is often devoid of its terminal phalanx. The orang utan lives in thick forests and is adapted for arboreal life, living mainly on fruit but also leaves, buds and young shoots. The animals live in small family groups and build shelters high in the trees which they move between by careful and deliberate swinging by the arms,
never leaping or jumping. Research Orang Utan
The arm is the upper limb in man, connected with the thorax or chest by means of the scapula or shoulder-blade, and the clavicle or collar-bone. It consists of three bones, the arm-bone (Humerus), and the two bones of the forearm (radius and ulna), and it is connected with the bones of the hand by the carpus or wrist. The head or upper end of the arm-bone fits into the hollow called the glenoid cavity of the scapula, so as to form a joint of the ball-and-socket kind, allowing great freedom of movement to the limb. The lower end of the humerus is broadened out by a projection on both the outer and inner sides (the outer and inner condyles), and has a pulley-like surface for articulating with the fore-arm to form the elbow-joint. This joint somewhat resembles a hinge, allowing of movement only in one direction. The ulna is the inner of the two bones of the fore-arm. It is largest at the upper end, where it has two processes, the coronoid and the olecranon, with a deep groove between to receive the humerus. The radius - the outer of the two bones - is small at the upper and expanded at the lower end, where it forms part of the wrist-joint. The muscles of the upper arm are either flexors or extensors, the former serving to bend the arm, the latter to straighten it by means of the elbow-joint. The main flexor is the biceps, the large muscle which may be seen standing out in front of the arm when a weight is raised. The chief opposing muscle of the biceps is the triceps. The muscles of the fore-arm are, besides flexors and extensors, pronators and supinators, the former turning the hand palm downwards, the latter turning it upwards. The same fundamental plan of structure exists in the limbs of all vertebrate animals. Research Arm
The carpus or carpals, consist of eight individual bones which compose each wrist. The small bones fit together in an exacting way to allow a wide range of flexibility in the wrist, while maintaining structural integrity. The eight bones of each wrist include the hamate, navicular, trapezium, pisiform, trapezoid, lunate, triquetrum, and capitate bones, which articulate with the metacarpals, the radius, and the ulna. Research Carpus
The flexor carpi ulnaris is used to bend the hand at the wrist. It gets its name from carpus (wrist bone) and the ulna (forearm bone). This muscle has two heads, one originates from the medial condyle of the humerus and the other originates from the olecranon and upper border of the ulna (forearm bone). The two heads combine to form a single, flat belly that tapers into a long tendon inserting in the pisiform bone of the wrist. It is innervated by the ulnar nerve and supplied by the ulnar artery. This muscle lies along the ulnar side of the forearm and works with the extensor carpi ulnaris to bend the hand at the wrist. If it continues to contract, it bends the elbow. Research Flexor Carpi Ulnaris
In animals, the foot is the lower extremity of the leg; the part of the leg which treads the ground in standing and walking, and by which the animal is sustained and enabled to step. The human foot is composed of twenty-six bones, seven of which constitute the tarsus or ankle, which articulates with the leg and corresponds to the carpus or wrist. Five bones form the metatarsus, which corresponds to the metacarpus, and articulates with the tarsus behind and the with the toes in front.
The hand is the part of the body which terminates the arm, and consists of the palm and fingers, connected with the arm at the wrist. The human hand is comprosed of twenty-seven bones, namely eight bones of the carpus or wrist arranged in two rows of four each, the row next to the fore-arm containing the scaphoid, the semilunar, the cuneiform, and the pisiform, and next the metacarpus, the trapezium, the trapezoid, the osmagnum and the unciform. The metacarpus consists of the five bones which form the palm, the first being that of the thumb, the others that of the fingers in succession. Lastly, the fingers proper contain fourteen bones called phalanges, of which the thumb has but two, all the other digits having three each. These bones are jointed so as to admit a variety of movements, the more peculiar being those by which the hand is flexed backwards, forwards and sideways, and by which the thumb and fingers are moved in different ways.
The chief muscles which determine these movements are the flexors, which pass down the fore-arm, are attached by tendons to the phalanges of the fingers and serve to flex or bend the fingers; and the extensors for extending the fingers. There are two muscles which flex all the fingers except the thumb. The thumb has a separate long and short flexor. There is a common extensor for the fingers which passes down the back of the fore-arm and divides at the wrist into four tendons, one for each finger, each being attached to all three phalanges. The forefinger and little finger have, in addition, each an extensor of its own, and the thumb has both a short and a long extensor. The tendons of the muscles of the hand are interlaced and bound together by bands and aponeurotic fibres, and from this results a more or less complete unity of action.
The radial vein is a large, deep vessel that accompanies the radial artery. The
radial vein runs from the hand, winds around the side of the dorsal side of the carpus (wrist), and extends along the radial side of the forearm to the elbow. It is joined by the ulnar vein to form the brachial vein. Research Radial Vein
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Gorilla
