Compact Bone. Compact bone consists of closely packed osteons or haversian systems. The osteon consists of a central canal called the osteonic (haversian) canal, which is surrounded by concentric rings (lamellae) of matrix.Between the rings of matrix, the bone cells (osteocytes) are located in spaces called lacunae.ompact Bone. Compact bone consists of closely packed osteons or haversian systems. The osteon consists of a central canal called the osteonic (haversian) canal, which is surrounded by concentric rings (lamellae) of matrix.
LEFTenant is the way British troops pronounce the rank Lieutenant. The two words mean different things within different military groups, but there is no actual difference. A British troop can refer to an American Lieutenant as  leftenant and not be incorrect.
Appurtenances are things that belong to and go with something else, the appurtenance being less significant than what it belongs to. The word ultimately derives from Latin appertinere, to appertain. In a legal context, an appurtenance could for instance refer to a back-yard that goes with the adjoining house. The idea being expressed is that the back-yard belongs to the house, which is the more significant of the two.