Milia are small, white cysts commonly seen around the cheeks. Overview. Milia are commonly found on the skin of people of all ages. They are formed when keratin (a substance produced by the skin) becomes entrapped beneath the outer layer of the skin, forming a tiny cyst. An individual milium (the singular of milia) is formed at the base of a hair follicle or sweat gland.
The basic first level structure of cortical bone are osteons. Trabecular bone is much more porous with porosity ranging anywhere from 50% to 90%. It is found in the end of long bones (see picture above), in vertebrae and in flat bones like the pelvis. Its basic first level structure is the trabeculae. III.
The osteon or haversian system /hÉËvÉr.ÊÉn/ (named for Clopton Havers) is the fundamental functional unit of much compact bone. Osteons are roughly cylindrical structures that are typically several millimeters long and around 0.2mm in diameter.he haversian canal contains the bone's blood supplies. The boundary of an osteon is the cement line. Between adjoining osteons, there are angular intervals that are occupied by interstitial lamellae. These lamellae are remnants of osteons that have been mostly destroyed.