Outlines of human osteology / by F.O. Ward.

  • Frederick Oldfield Ward
Date:
1876
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of human osteology / by F.O. Ward. Source: Wellcome Collection.

    378/392 page 358
    short bones; each gives attachment and mproved tlT^l■ ^ ^ ™,=l«%?f extensors; and each protects a jomt, which would otherwise be exposed durin. flexion Wiien the olecranon remains separate from the ulna, and lorms an independent short bone (as in an iustauoe re- ^°senm_uller), this analogy is rendered com- plett. the analogies between the forearm and the le<^ are, m several respects, more uncertain than those be° tween the upper arm and thigh. The leg is indeed, like the torearni, composed of two parallel prismatic bones, articulated together above and below, and havincr their shalts connected by an interosseous membrane. But, with re.spect to the precise analogies of these two bones, difterent opinions are entertained by anatomists, the tibia bemg compared by some to the ulna, and by others to the radius At its upper extremity the tibia certainly resembles the ulna; because it is in a line with the inner side ot _ the bone above, and because moreover it pos- sesses, in the patella, an appendage analogous to the olecranon. At its lower extremity, on the contrary, the tibia resemb es the radius, first, because it contributes more than the fibula to the ankle-joint, as the radius contributes more than the ulna to the wrist; secondly, and chiefly, because it is in a line with the great toe, as the radius is with the thumb. Here, therefore, it must he admitted that the analogy of the two limbs is some- what obscure. It is, however, impossible to dispute the resemblance between the malleoli of the ankle-joint and the styloid processes of the wrist; between the cuboid bones of the tarsus and those of the carpus ; between the cylindrical bones of the metatarsus and those of the metacarpus ; and, finally, between the phalanges of the fingers and toes. 438. If these strong analogies between the upper and lower extremities compel us to admit that they are foraied m a common type, their numerous and important djfiei-ences are, on the other hand, sufficient to prove that that type has undergone considerable modifications, to adapt it in each case to particular functions. This is a PO'^t on which we have already had occasion to dwell (•303); and we need here, therefore, only remind the student (by way of recapitulation,) tbat the bones of the arm, m which freedom, swiftness, and delicacy of motion, are the principal requisites, present slender shafts, shal- low articulations, and short processes for the attachment
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