Talk about the two layers of perichondrium.

- Chondrogenic layer (deep layer formed of loose CT, poorly vascularized, makes connection with cartilage rich in cells and deepest mesenchymal cells and fibroblast differentiate into chondroblasts that synthesize cartilage ECM. -Tediniform layer: composed of fibrous dense irregular CT (collagen and elastin and dispersed fibroblasts), highly vascularized, fibrous layer of perichondrium.