VAN 211: Veterinary Histology and Embryology (2+2)

SKELETAL SYSTEM

• The skeletal system is a mesodermal derivative. Bone a always develops by a transformation of the embryonic or adult connective tissue.
• When development of bone takes place in cartilage, the method of ossification is termed enchondral ossification.
• When it occurs in membrane the process is termed intramembranous ossification but essentially the process is the same in both.
• Bone matrix is deposited the activity of specialised connective tissue cells called osteoblasts.
• The only difference between the two types of ossification is that the former occurs at first in cartilage which is destroyed - replaced and substituted by bone. Hence bones formed in this way are also known as substitution bones e.g. long bones of limbs.
• The flat bones of the skull are membrane bones.