The skeleton of a horse is the framework of his body. It supports and protects his organs and soft tissue with 206 bones of all shapes, sizes, and structural and mechanistic purposes. Bone is living tissue, supplied with blood vessels and nerves. Toward its surface it is hard, while the inner bone is spongier, which gives the bone its lightness and resilience. Tendons and ligaments are elastic fibrous bands that help support and stabilize the bones. They are attached to the bone via the periosteum, which is a thin layer of tissue that covers and protects the bone. Perforation of the periosteum, which can happen with punctures wounds and breaks, can prevent proper healing.
Figure 3.2: The Skeletal System
A working knowledge of your horse's skeletal system and anatomy can help you determine when and where your horse is having a lameness issue, or at least be able to convey what you are seeing to a vet, using the appropriate terminology. The quicker and more accurately you can close in on a problem, the more likely you are to save your horse from unnecessary discomfort, while saving yourself time and money.
A thin-skinned horse, such as an Arabian or thoroughbred, can afford you a better observation of the skeleton and points of a horse. Such a horse in motion can remove the abstraction of science and really give you an appreciation of how the skeletal system actually carries a horse.
One of his many adaptations for speed and endurance, a horse's skull has large sinus cavities that not only make his head less of a weight burden by decreasing heavy bone, but are also capable of holding and passing great amounts of oxygen into his system, which is then translated into energy.