Dissection of the Foot.
So far we have only described the outer covering of the foot and the structure from which it grows and by which it is connected to the parts within. A little deeper examination is necessary to understand the mechanism of the whole organ.
Fig. 11.—Section of Foot.
If we divide into two lateral halves a foot cut off at the fetlock joint, we have a section which should show the whole of the deeper structures. In the centre we see the three lower bones of the limb—the pastern, coronet, and pedal. ([Fig. 11]). On the front surface of these bones we notice a tendon or sinew which comes from above the knee and is fixed to the upper part of the pedal bone. At the back of the bones two very large tendons run down and are fixed on the last two bones. These tendons are the structures through which the movements of the foot are made. They have in themselves no power of contraction but they are connected above the knee, and in the hind leg above the hock, to powerful muscles which possess the power of contraction. When these muscles contract the tendons are drawn up towards knee or hock, and so move the foot backwards or forwards.
To permit movement of one bone upon another the ends of the bones are suitably shaped, and covered with a layer of gristle or cartilage. To limit the movement and to hold the bones together the ends of each bone are surrounded by ligaments, and thus we have joints formed.
Fig. 12.—Side view of Pedal Bone.