Dermal bone forms directly in the skin from mesenchyme. Osteoblasts form a calcium phosphate matrix and deposit salts, they then become osteocytes. Dermal bones are plate like, but can become thicker or grow at the edges. Membrane bones are deep bones that also do not have a primary cartilage matrix. Give some examples of dermal bones seen in this lab.
New cartilage grows mainly at the ends and at epiphyses to lengthen the bone.
To widen it, the periosteal membrane directly secretes perichondrial bone in strips. The axial skeleton was derived from scleratome, the appendicular skeleton from myotome. Give some examples of replacement bones seen in this lab. Examine the microscope demonstration of dry ground bone. The forming of this complex structure is called ossification.