Compact bone and cancellous bone,
ed bone, H&E,
Bone has a calcif ed extracellular matrix that is very diFf
cult to cut into thin sections. In order to have thin sections
with H&E stain, these bone specimens have to go through
a decalcif cation process that removes calcium compounds
From the specimen. Bone can be classif ed as
based on its gross appearance.
has a very
high density and a well-organized osteon system (±igs. 5-8
and 5-9A–C). It has no trabeculae and usually Forms the
external aspect oF a bone.
has a much lower density and contains
. It usually Forms
the inner part oF a bone, also called
, and is
commonly Found between the inner and the outer tables oF
the skull, at the ends oF long bones (limbs and f ngers), and
in the cores oF other bones.
Compact bone, f
105; inset (
154; inset (
An example oF
From the diaphysis oF the long
nger) is shown. The internal surFace is covered by
a single layer oF connective tissue cells Forming the
. It contains osteoprogenitor cells, which are capable
oF diFFerentiating into osteoblasts. The external surFace is
covered by a thicker layer, the
, which contains
blood vessels, nerves, and osteoprogenitor cells. Osteopro-
genitor cells can diFFerentiate into
, which have
the ability to produce bone matrix,
5-11A). Blood vessels branch to supply bone through a
system oF interconnected
are arranged uniFormly in
compact bone. Each osteocyte occupies one lacuna, which
has no isogenous group as it does in cartilage (±ig. 5-9C).
Cancellous bone (spongy bone), nasal.
ed bone, H&E,
bone is also called
. It has a lower
density than compact bone and consists oF
, within a marrow-f
lled cavity. Osteoblasts
line the surFace oF the bony trabeculae. Cancellous bone
displays irregular shapes in the trabecular network.
f lls the space between the bony trabeculae (±ig.
5-11A). Most osteocytes in the matrix are arranged in an
irregular pattern rather than in circular rings (±ig. 5-8).
Cancellous bone mainly Forms the inner core oF bone and
provides (1) a meshwork Frame that supports and reduces
the overall weight oF bone and (2) room For blood vessels
to pass through and a place For marrow to Function as a
hemopoietic compartment, housing and producing blood
cells (±ig. 5-11A).