Search results
Results from the WOW.Com Content Network
Sixty percent of the dog's body mass falls on the front legs. [14] The dog has a cardiovascular system. The dog's muscles provide the dog with the ability to jump and leap. Their legs can propel them to leap forward rapidly to chase and overcome prey. They have small, tight feet and walk on their toes (thus having a digitigrade stance and ...
The deep muscles arise from the distal part of the ulna and the surrounding interosseous membrane. The brachioradialis , flexor of the elbow , is unusual in that it is located in the posterior compartment, but it is actually a muscle of flexor / anterior compartment of the forearm.
The ulna is ossified from three centers: one each for the body, the wrist end, and the elbow end, near the top of the olecranon. Ossification begins near the middle of the body of the ulna, about the eighth week of fetal life, and soon extends through the greater part of the bone. At birth, the ends are cartilaginous.
When the forearm is extended and supinated, the axis of the arm and forearm are not in the same line; the arm forms an obtuse angle with the forearm, known as the carrying angle. During flexion, however, the forearm and the hand tend to approach the middle line of the body, and thus enable the hand to be easily carried to the face.
The number of digits, their characteristics, as well as the shape and alignment of radius, ulna, and humerus, have had major evolutionary implications. Changes in body size, foot posture, habitat, and substrate are frequently found to influence one another (and to connect to broader potential drivers, such as changing climate). [3]
Its fibres run perpendicular to the direction of the arm, running from the most distal quarter of the anterior ulna to the distal quarter of the radius.It has two heads: the superficial head originates from the anterior distal aspect of the diaphysis (shaft) of the ulna and inserts into the anterior distal diaphysis of the radius, as well as its anterior metaphysis.
The styloid process of the ulna projects from the medial and back part of the ulna. It descends a little lower than the head. The head is separated from the styloid process by a depression for the attachment of the apex of the triangular articular disk, and behind, by a shallow groove for the tendon of the extensor carpi ulnaris muscle.
The forearm (Latin: antebrachium), [5] composed of the radius and ulna; the latter is the main distal part of the elbow joint, while the former composes the main proximal part of the wrist joint. Most of the large number of muscles in the forearm are divided into the wrist, hand, and finger extensors on the dorsal side (back of hand) and the ...