THE MORPHOMETRIC CHARACTERISTIC OF ARTERIAL DICHOTOMIES OF THE
LIVER VASCULAR BED.
P.A. Topolov, O.K. Zenin, A.V. Dmitriev, P.V. Kudymov, A.E. Khudyikov.
Feature of an arterial channel of a liver is presence of a considerable quantity of vascular
dichotomies. In the literature there are a series of the works devoted to their research, however,
devoted detailed morphometric analysis of interrelations of diameters of segments compounding
dichotomy of a liver vascular bed apparently not enough. Therefore the purpose of the present
work was morphometric research of interrelations of internal diameters of the arterial segments
compounding a dichotomy – a base unit of a liver vascular bed.
Corrosion casts of an arterial channel of a liver almost healthy 5 men who were lost from
asphyxia, at the age of 38 – 47 years have been studied. Dichotomies in total of 1603 pieces have
been included in research only. The D – diameter of a parent arterial segment, dmax – diameter
of the maximum filial branch, dmin – diameter of the minimum filial branch were measured. The
asymmetry ratio γ = (dmin/dmax)2; area ratio η = (dmax2 + dmin2)/D2; and D/dmax and D/dmin
– quotients of division of a parent artery were counted. Statistical processing included
calculation of the basic indexes of allocation of variates.
During research presence of 4 structurally-various of arterial dichotomies is positioned.
Presence of authentic differences between values of medians, the indexes quantitatively
characterising dichotomies of structurally-various types was revealed. Dichotomies with full
asymmetry (1st type - D≠dmax≠dmin) 46 % were revealed; with lateral asymmetry (2nd type D=dmax, D≠dmin, dmax≠dmin) – 30 %; with one side symmetry (3rd type - D≠dmax, D≠dmin,
dmin=dmin) – 23,5 % and with full symmetry (4th type - D=dmax=dmin) – 0,5 %. For
dichotomies of 1st type are characteristic: the greatest value of parameters (Me±m, here in and
under the text) D = 0,7±0,04 mm, values γ = 0,25±0,01, η = 0,78±0,01, D/dmax = 1,33±0,03 and
D/dmin = 2,5±0,19 mm - occupy center position, among sizes of parameters of the investigated
dichotomies. For dichotomies of 2nd type are characteristic: the greatest values of parameters – η
= 1,11±0,01 and D/dmin = 3±0,16; the least values – γ = 0,11±0,01 and D/dmax=1, value D =
0,5±0,03 mm - occupies center position, among sizes of parameters of the investigated
dichotomies. For dichotomies of 3rd type the greatest values of parameters γ = 1 and D/dmax =
2±0,06, the least value – D = 0,3±0,02 mm, η = 0,5±0,02 and D/dmin = 2±0,06, among sizes of
parameters of the investigated dichotomies are characteristic.
Established facts contradict V. Ruex known principle - the minimum expenses of a
biological stuff and the energy going on functioning of a vascular dichotomy. It bases on the
assumption that the basic function of a vascular branching is carrying out of blood with the
minimum energy consumptions. And its practical realization in the conditions of an arterial
channel is carried out, by the coordination of diameters of arteries compounding a dichotomy.
CONCLUSIONS:
1. Four structurally-various types of arterial dichotomies are found. Structural differences
of arterial dichotomies, possibly, define distinctions of functions carried out by them.
2. The optimality principle should be formulated according to distinctions of functions
carried out by arterial dichotomies; therefore for different types of dichotomies the figures
testifying to optimality should not have identical value.
3. The found laws should be considered at mathematical modeling of frame of an arterial
channel of a liver.