Cartilage grows in two distinct ways: appositional growth and interstitial growth.
Understanding Cartilage Growth
Cartilage, a vital component of the skeletal system, doesn't grow in just one way. It employs two different mechanisms to increase its size and mass. These mechanisms are crucial for development, repair, and maintaining the structural integrity of the body.
Two Distinct Patterns of Cartilage Growth
The two patterns are:
- Appositional Growth: New cartilage is added to the surface of existing cartilage.
- Interstitial Growth: New cartilage is formed from within existing cartilage.
| Growth Type | Location of Growth | Mechanism |
|---|---|---|
| Appositional | Perichondrium (surface) | Cartilage cells grow from the perichondrium, adding new layers to the existing cartilage. |
| Interstitial | Within existing cartilage | Chondrocytes within the cartilage divide and produce new matrix. |
Appositional Growth Explained
Appositional growth is similar to adding layers to the outside of a structure. According to the reference information, this type of cartilage growth "occurs when cartilage cells grow from the perichondrium." The perichondrium is a layer of dense connective tissue that surrounds the cartilage. Cells within the perichondrium differentiate into chondroblasts, which then produce new matrix and become chondrocytes.
Interstitial Growth Explained
Interstitial growth is like expanding from within. The reference states that "if the cartilage cells grow from the chondrocytes within the cartilage, it is called interstitial growth." Chondrocytes, cartilage cells, divide and secrete new matrix. This process increases the cartilage's size from the inside.
Practical Insights and Examples
- Development: Both appositional and interstitial growth are important during skeletal development.
- Repair: Appositional growth plays a role in cartilage repair.
- Location: Interstitial growth only occurs in young cartilage, where the matrix is still pliable.
