Biomedical Engineering Reference
In-Depth Information
Figure 1.3
Aprotozoan
Leishmania donovani
in a bone mar-
row cell. Leishmania is a genus of parasites that are the
etiologic agents of diseases of humans, such as leishmani-
asis. After [34].
normal flora found on the skin and mucous membranes. In children, osteomyelitis
usually affects the long bones of the arms and legs. Osteomyelitis often requires
prolonged antibiotic therapy, and may require surgical debridement. Severe cases
may lead to the loss of a limb [35, 36].
Leishmania
is a genus of trypanosome protozoa and is the parasite responsible
for the disease leishmaniasis, Figure 1.3. It is spread through sandflies.
Leishmania
commonly infects vertebrates: hyraxes, canids, rodents, and humans [34].
The body also contains the body fluids such as blood and lymph, as well as
fluids that are secreted by other organs [9]. The bones are laid down as excretions
of bone-making cells, called
osteocytes
. The quantitative proportion of cells in the
mass of cartilage and bone is very low, while the major part is taken by extracellular
substances. In the hollow interior of bones, bone marrow tissue is found. In
adults, marrow in large bones produces new blood cells. It constitutes 4% of total
body weight. The bone marrow is composed of stroma and parenchyma parts.
Hematopoiesis is performed by parenchymal cells, while the stroma provides
hematopoietic microenvironment.
Interaction of huge biomolecules with precision and infallibility is the essence of
the living state. Looking at cell metabolism in relation to the intricate structure of
a cell Peters (1930) stated that in the cell ''extreme order has to be reconciled with
afluidanatomy(
). The cell must be considered as a reflex entity, structurally
organized so far as even its chemistry is concerned, with chains of chemical
substances acting as it were as reflex arcs (
...
). It is perfectly possible to appreciate
how a coordinated structure may be maintained in a medium which is apparently
liquid. This theory is all, that is, needed to enable us to understand how substances
can reach a special site in the cell. Between the chains of molecules, fixed by their
radiating webs, there will exist paths from the external to the internal surface, the
capillaries of the cell'' [37].
...
