The
Microcirculation
211
Mayrovitz
(1
975, 1976) and Noordergraaf
(1
978) provided an analysis
of
a model of the
microcirculatory dynamics. The bat wing was selected
for the ease of accessibility and measurements of the microvascular bed
parameters.
A
distributed model was developed based on the wing's
vascular anatomy. The topology of this model is shown in Fig.
7.3.4
which includes a perfusing artery, arterioles and collecting venules and
a
vein, as well
as
capillaries, precapillary sphincter. Geometric dimensions
of
the branching structure are also shown in the table. Poiseuille formula
was utilized for describing small vessel pressure-flow relationship.
Pressure distribution along the vascular bed and its change due to
diameter alteration of fourth order branching vessels are shown in Fig.
7.3.5
during
control,
simulated
contraction
and
vasodilation.
Experimental results provide a validation that the model predicted
pressure distributions are reasonably accurate.
A
MAIN ARTERY ENTERING WING
(0)
4
\ARTERIES
'
R
in
ALL
1
A'
A2
ARTERIOLES
10
in
ALL
SMALL
WTERY
I2
in
ALL
SMALL
ARTERY
(2)
A3
w
Fig.
7.3.4:
Topological model
of
the microvascular bed of the bat wing. One pathway
for
a main artery
to
a vein is displayed. The branching order
is
numbered and the particular
sites are denoted by
A,-&.
Terminal arteriole
(T.
ARTLE),
precapillary sphincter
(P.C.S.),
CAP
(capillary) and post-capillary
venule
(P.C.V.)
are also
marked.
Corresponding geometric dimensions are also shown in the table.
From Mayrovitz
(1
976).
