what is the function of the chondrogenic layer of the perichondrium
Perichondrium The perichondrium (from Greek περί (peri 'around') and χόνδρος (chondros 'cartilage')) is a layer of dense irregular connective tissue that surrounds the cartilage of developing bone. It consists of two separate layers: an outer fibrous layer and inner chondrogenic layer. The fibrous layer contains fibroblasts, which produce collagenous fibers. The chondrogenic layer remains undifferentiated and can form chondroblasts or chondrocytes. Perichondrium can be found around the perimeter of elastic cartilage and hyaline cartilage.
Eggshell The fibrous chicken shell membranes are added in the proximal (white) isthmus of the oviduct.[1] In the distal (red) isthmus mammillae or mammillary knobs are deposited on the surface of the outer membrane in a regular array pattern.[7][8] The mammillae are proteoglycan-rich and are thought to control calcification. In the shell gland (similar to a mammalian uterus), mineralization starts at the mammillae. The shell gland fluid contains very high levels of calcium and hydrogen carbonate. The thick calcified layer of the eggshell forms in columns from the mammillae structures, and is known as the palisade layer. Between these palisade columns are narrow pores that traverse the eggshell and allow gaseous exchange. The cuticle forms the final, outer layer of the eggshell.[9]