a) The structural unit of bone tissue is called Haversian system.
b) It consists of a central Haversian canal containing blood vessels and nerves.
c) It is surrounded by a matrix called ossein.
d) Ossein contains collagen fibres and mineral salts chiefly calcium phosphates.
e) Ossein is arranged in the form of concentric layers called lamellae.
f) There are fluid filled spaces between lamellae called lacunae.
g) There are fine canals interconnecting the lamellae called canaliculi.
h) The osteocytes are interconnected by protoplasmic strands extending through the
canaliculi.