Biomedical Engineering Reference
In-Depth Information
There are two methods of preparing sections for microscopy. One method
provides the dry bone section. A piece of dead bone is broken or sawed from the
main bone. Next, it is ground and polished to be very thin (about 15-45
mthick).
That polished piece is placed on a microscope slide and viewed directly. The bone
cells are missing from the dead, polished bone specimen, and in a humorous
sense one is looking at a skeleton of the skeleton. A second method for obtaining
bone for histology is to soak a piece of bone in an acid solution for some time.
The acid treatment dissolves the bone salts from the tissue in a process called
demineralization
. With this method, the cells stay behind and can be stained before
observation under the microscope, cf. [87].
It is seen in Figure 1.12 that the bone is porous at two scales: containing macro-
pores measuring 100
µ
m or more (Haversian and Volkmann's canals, lacunae),
and micropores measuring up to 0
µ
20 nm) in diameter (canaliculi). The
double porosity and interconnectedness of pores enable the bone to fulfill two vital
.
02
µ
m(
=
Fibrous layer of periosteum
Osteogenic layer of periosteum
Outer circumferential
lamellae
Lacunae containing osteocytes
Canaliculi
Cementing line
pa
Interstitial lamellae
Haversian system
Inner circumferential lamellae
Blood vessel
and
endosteal lining
of
haversian canal
Volkmann's canals
Blood vessels into marrow
Endosteum
Figure 1.12
Design of the microstructure of cortical bone. After Piekarski and Munro [88].
