50 PRINCIPLES OF VETERINARY SCIENCE 



The scapula has a larger spine which is placed nearer the anterior 

 border and has a prominent projection below. 



The humerus has a less prominent deltoid tuberosity than 

 in the horse and has a hook-like process which curves over the 

 bicipital groove. 



The radius is short, relatively broad, and fuses its entire length 

 with the ulna, which is more fully developed than in the horse 

 and articulates with the ulnar carpal. 



The carpus consists of six bones, four in the upper row and two 

 in the lower. 



The metacarpus consists of a large bone, formed by fusion of 

 the third and fourth bones of the fetus, and an external splint 

 corresponding to the fifth metacarpal of five-toed vertebrates. 

 The cannon has a distinct vertical groove which marks its double 

 origin. At the distal end it is divided into two parts by a deep 

 notch. The splint is only about one inch long. 



The digits of the ox are four in number. Of these, the third 

 and fourth are fully developed and have three phalanges each. 

 The second and fifth are vestiges placed behind the fetlock and 

 do not articulate with the rest of the skeleton. 



The ilia are parallel to each other and relatively small. 



The femur is shorter and much smaller than in the horse. 



The tibia has a curved shaft and the grooves at the distal end 

 are directed nearly straightforward. 



The other bones of the hind limb resemble those in the fore limb. 

 THE CONSTRUCTION AND WORK OF THE JOINTS 



A joint is the union of two or more bones or cartilages. Joints 

 are classified, according to structure, into three types: 



Type I, immovable, in which the opposed surfaces are directly 

 united by connective tissue, e.g., joints between the bones of the 

 skull. The periosteum also assists in this union. 



Type II, slightly movable, in which the bones are united by 

 cartilage that is elastic enough to permit a slight movement, e.g., 

 the intervertebral joints. 



Type III, freely movable, in which a joint cavity 1 exists 

 between the opposed surfaces, e.g., hinge-joint, as that of the 



1 The joint cavity is a potential cavity and does not actually exist in the 

 sense of a space occupied by air. When the bones of the articulation are 

 forcibly pulled apart there may be a small space, but it is largely filled with 

 synovia. 



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