
Physiological aspects on pharmacokinetics 83
H
2
(t)
H
1
(t)
a) Parallel organs
?
Q
?
Q
1
Q
2
6
6
Q
Q
1
Q
2
H
2
(t) H
1
(t)
b) Organs in series
QQ
Q
6
?
Intestines
Liver
c) Intestine-liver system
?
6
QQ
1
Q
2
Q
2
Q
FIGURE 4.2: Elementary organ connections
Next we consider two organs in series; see Figure 4.2(b). Now the flow is
the same over each organ and we have C
1
= H
1
∗ C
in
and C
out
= H
2
∗ C
1
.So
it follows that H = H
2
∗ H
1
and consequently
MTT(H)=MTT(H
1
) + MTT(H
2
).
Other examples can be built from this. For example, the intestines-liver sys-
tem shown in Figure 4.2(c) can be considered built up of two parallel organs,
one consisting of a part of the liver alone, the other of the rest ...