Question

Ossification is the process by which
a. Cartilage is formed
b. Bone is formed
c. Connective tissue is formed
d. None of the above

Answer 1

Ossification is the process of making of bones. Ossification is of two different types one is the intramembranous, in which development of fibrous connective tissue occurs. Cranial bones are formed by this process. The center of ossification appears in the fibrous connective tissue membranes. Cartilage develops into bony tissue by the process of endochondral ossification. Formation of connective tissue is the part of ossification.

Complete answer:
Mesenchymal cells form clusters and differentiate into osteoblasts, forming an ossification center. Collagen fibers surround the osteoblast. There are mainly three parts present in the cluster that are ossification center, osteoid, and osteoblast. Mesenchymal cells are called embryonic cells so it can be said that these are developed from embryo tissue. Formation of these structures occurs in the first step.

In the second step, the bone matrix (osteoid) is secreted within the fibrous membrane. Osteoid began to mineralize within a few days. Trapped osteoblasts become Osteocytes. These are mature bone cells.

In step three, spongy bone or woven bone is formed. In this step, blood vessels woven through and form a network of trabeculae.

At the end, a bone collar of compact bone forms and red marrow appears. Once this form we have the fully formed spongy bone. These steps involved in intramembranous ossification. Cranial or skull bones are formed by this process.

Endochondrial ossification occurs at the other bones of the body besides skull and cranial bones. These are formed in foetus. In this process, hyaline cartilage is replaced with bony tissue.

Ossification is the process which results in the formation of normal, healthy bone tissue.

From the above information we can say that ossification is the process of formation of bones.
Hence, the correct answer is option (B).

Note: Ossification in long bones begins in the third month of fetal development and by the age of 25 nearly all the bones are ossified. Heterotrophic ossification is the process of formation of bone tissues at an extra skeletal location. Calcification is different from ossification. Calcification is the formation of calcium based salts within the cells and tissues.