Art02

PRACTICAL RECOMMENDATIONS ON SOME PHYSIOLOGICAL CONSTANTS OF HUMAN BODY.

(For students and doctors under specialization).

The International System of Units (SI) was adopted on the XI General Conference on Measurements and Weightings in 1960 and is being integrated in various spheres of life since 70-th in all the states of the world.

The use of SI in medicine is adopted on The XXX World Assembly On the Health Protection in May, 1977.

The use of SI in the USSR is determined by State Committee on Standards in 1979, June 25, Doc. No.2242, according to which the standard of The Council on the Mutual Economic Assistance No. 1052-78 is prolonged as The USSR State Standard since January 1, 1980.

The advantage of the SI is in fact that it presents the essence of physical world and is based on only several units. It describes different branches of science and technics and contains seven principal and two additional units (Table 1).

When translating in SI, the required exactness of the unit should be taken into account. The result can be represented as a Table or a Picture, convenient for the application.

If we want to derive the unit of the amount of the subject from the mass unit we should use the coefficient 1000/Mr; here Mr is the molar mass of the subject. Atomic masses of the subjects, that are applied in everyday clinic's practice, are represented in Table 14.

For example: blood contains 1,50 g/l of glucose; its relative mass is 180. The coefficient will be 1000/180=5,5. Finally we multiply 5,5 and 1,5 and have 8,3 mmol/l.

Here we represent some derivatives being applied in medicine:

1. Frequency; Hertz: 1[Hz]=1/sec. Pulse and respiration can also be measured in 1/min.

2. Volume; m3 - cubic meter.

3. Mass - the scalar unit of gravitate and inertial properties of body; [kg]. The weight - that is a vector unit - is measured in Neutons: [N]

4. Flow, volume speed - m3/sec.

5. Pressure - force derived by normal component of square: Pascal; 1Pa= 1N/m2. 1 mm mercury level equates 133,332 kPa; 1 mm water level = 9,80666 Pa.

6. Work, amount of heat, warmth of chemical reactions are measured in Jowls and 1cal = 4,1868J.

7. Relative density (partial weight) - relation of density of liquid substance to the one of water.

These recommendations are done for students and doctors under specialization.

Table 1. Principal and additional units of SI.

measured figure	unit name	Russian name	international name
Principle
Length	meter	м	m
mass	kilogram	кг	kg
time	second	с	s
electric power	Ampere	А	A
temperature	Kelvin	К	K
amount of substance	mol	моль	mol
amount of light	candela	кд	cd
Derivatives
flat angle	radian	рад	rad
Volume angle	steradian	ср	sr
Derivatives
square	square meter	м2	m2
volume	cubic meter	м3	m3
pressure	Pascal	Па	Pa
Some of physical constants.
mass concentration	kilogram in cubic meter	кг/м3	kg/m3
density	kilogram in cubic meter	кг/м3	kg/m3
molarity	mol in cubic meter	моль/м3	mol/m3
partial molarity	mol in kilogram	моль/кг	mol/kg
activity of catalisator	mol in second	моль/c	mol/s
speed of reaction	mol in second in cubic meter	моль/c*м3	mol/s*m3
clearance	cubic meter in second	м3/с	m3/s

Table 2. Units, applied together with SI.

measured figure	unit
measured figure	name	Russian name	Inter. name	derivation	remarks
time	minute	мин	min	60 s	also available: week month, year.
volume	liter	л	l	0,001m3
speed of eryth rocite's sink	mm/ hour	мм/ ч	mm/h	0,0000002778m/s
density	kg/l	кг/л	kg/l	1000kg/m3
clearance	liter in second	л/с	l/s	0,001m3/s
some physiologicalconstants.
temperature	degree Celsium	C	C		thermodynamical temperature minus273,15 degrees.
speed of reaction	mol in second in liter	моль/c*л	mol/s*l	1000 mol/(s*m3)
molarity	mol in liter	моль/л	mol/l	1000mol/m3
relative:
density	unit	---	---	1
partial mass	percent	%	%	0,01
molar part	promille	%o	%o	0,001
volume part	one of million	млн-1	ppm	0,000001