Question

When chondrocytes in lacunae divide and form new matrix, it leads to an expansion of the cartilage tissue from within. This process is called __________. a) appositional growth b) hematopoiesis c) interstitial growth d) calcification.

Answer 1

Answer:

c) interstitial growth

Explanation:

Cartilage growth is effected by two types of mechanisms: apposition or exogenous growth and interstitial or endogenous growth.

Growth by apposition. From the inner layer of the perichondrium, new layers of cartilage are produced continuously by proliferation of mesenchymal cells that are arranged in the deepest area of ​​the perichondrium. These cells differ in chondroblasts, which secrete amorphous fundamental substance and collagen fibers, leaving the cells included in said substance. The cartilage grows outward by the apposition of successive layers.

In interstitial growth, chondrocytes usually gather in small groups, called isogenic groups or cell nests, each consisting of the progeny of a chondrocyte that has passed through several mitotic divisions.

Once the cytoplasm constriction occurs in the cells that are in the process of division, an intercellular substance septum develops between them, separating the daughter cells. These, in turn, can give rise to groups of four cells. In this way interstitial growth develops two types of arrangements: if mitosis is performed in only one direction we have a group of aligned chondrocytes (axial isogenic group), but if the divisions are performed in all directions, we have a coronary isogenic group.

In the epiphyseal lines of the long bones the cellular division of the chondrocytes occurs in a plane, resulting in the ordering of long columns, which are subsequently invaded by the bone tissue.

The division of the chondrocytes and the secretion of a new matrix between the cells, leads to an expansion of the cartilage from the inside.