ribonucleic acid, RNA (noun). (biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes; it transmits genetic information from DNA to the cytoplasm and controls certain chemical processes in the cell.
Osteocytes â mature osteoblasts. Osteoclasts â bone-destroying cells. Compact bone A structural unit of a compact bone is called an osteon (or Haversian system). Osteon â cylindrical structure oriented parallel to bone's long axis.Osteon consists of hollow tubes, one inside the other, called lamella.steocytes â mature osteoblasts. Osteoclasts â bone-destroying cells. Compact bone A structural unit of a compact bone is called an osteon (or Haversian system). Osteon â cylindrical structure oriented parallel to bone's long axis.Osteon consists of hollow tubes, one inside the other, called lamella.
The cortical (compact) bone is one of the three layers of a bone. It is a dense, rigid bone called the compact bone. It is shaped like a cylinder and is so hard that surgeons must use a saw to cut through it.he cortical (compact) bone is one of the three layers of a bone. It is a dense, rigid bone called the compact bone. It is shaped like a cylinder and is so hard that surgeons must use a saw to cut through it.