Page 88 - Anatomy and Physiology of Farm Animals, 8th Edition

The Skeletal System / 73

Articular cartilage Articular cartilage
VetBooks.ir Proximal

Epiphyseal epiphysis
cartilage

Metaphysis
Cancellous
(spongy) bone

Compact bone

Diaphysis
Medullary
Periosteum cavity

Endosteum

Metaphysis

Articular cartilage
Distal
epiphysis

Figure 4-3. Longitudinal section of the equine femur. Left, immature (growth plates open). Right,
mature (growth plates fused).

depressions may be articular or nonar- Long bones are greater in one dimen-
ticular. If they are articular, they form an sion than any other. Each consists of a
integral part of a joint and are covered relatively cylindrical diaphysis and two
with articular cartilage. Nonarticular pro- extremities, the epiphyses, with a metaph-
jections and depressions exist outside of ysis between each epiphysis and the dia-
joints. Many of them provide areas for physis. The best examples of long bones
attachment of muscle tendons or of liga- are in the extremities where they function
ments. Table 4‐1 lists some common bony primarily in support and locomotion. In
features. the thoracic limb, the long bones include
the humerus, radius, ulna, metacarpals,
and phalanges. In the pelvic limb, the long
Classification of Bones According bones are the femur, tibia, fibula, metatar-
to Gross Appearance sals, and phalanges.
Short bones are cuboidal, or roughly
Any bone may be classified in one of the equal in all dimensions. Short bones absorb
following groups: long, short, flat, sesa- concussion, and they are found in complex
moid, pneumatic, or irregular. joints such as the carpus (the “knee” of the