What is the Difference Between Interstitial and Appositional Growth?

Interstitial and appositional growth are two essential mechanisms that contribute to tissue development, maintenance, and repair in plants and animals. The main differences between them are:

Location of growth: Interstitial growth occurs by the addition of new cells within the existing tissue, while appositional growth involves the addition of new cells to the surface of the tissue.
Tissues involved: Interstitial growth occurs in tissues that have the capacity to divide, such as cartilage and bone tissues. Appositional growth, on the other hand, occurs in tissues that do not have the capacity to divide.
Function: Interstitial growth results in the increase in the length of bones due to cartilage lengthening and replacement by bone tissue. Appositional growth allows bones to grow in diameter and can continue throughout life.

In summary, interstitial growth allows bones to grow in length, while appositional growth allows bones to grow in diameter. Interstitial growth occurs within lacunae, whereas appositional growth occurs on the surface of pre-existing tissues.

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What is the Difference Between Interstitial and Appositional Growth?

Comparative Table: Interstitial vs Appositional Growth

Here is a table comparing interstitial and appositional growth:

Feature	Interstitial Growth	Appositional Growth
Definition	Involves the addition of new cells within the existing tissue.	Involves the addition of new cells to the surface of the tissue.
Growth Type	Occurs in tissues that have the capacity to divide, such as cartilage and bone tissue.	Occurs in tissues that do not have the capacity to divide, such as the outer layer of bone tissue and the skin.
Bone-related	Allows bones to grow in length, specifically through the lengthening of hyaline cartilage in the epiphyseal plate.	Allows bones to grow in width or diameter, contributing to the formation of a new layer of skin and increasing bone strength and mass.
Location	Occurs within the lacunae.	Occurs at the endosteal and periosteal surfaces of bones.
Growth Duration	Ceases at a particular time when the epiphyseal plate closes.	Can continue throughout life, as long as the bone structure remains intact.

In summary, interstitial growth is the process by which bones grow in length, while appositional growth is the process by which bones grow in diameter and the skin forms a new layer. These growth mechanisms are essential for maintaining and repairing tissues in the body.

Guilherme Mazui

Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.