Vessels activity main indexes:

• velocity,

• pressure,

• pulse.

Blood movements velocity types:

1. Volumetric velocity – blood amount flowing through transversal vessel section in time unit. It is expressed in ml/min and depends on pressure gradient at vessel beginning and end as well as on resistance to blood stream. Its size depends on organ state (for instance, in course of muscular activity this velocity increases in them in tens times). This velocity is determined by rheography method.

2. Linear velocity – distance which blood particle passes through time unit. It is determined in m/sec and is under norma:

• in aorta – 0,5-1,0 m/sec,

• large arteries – up to 0,5 m/sec,

• in veins – 0,25 m/sec,

• in capillaries – 0,05 m/sec.

Investigation methods: direct – stains and different substances introduction; indirect – ultrasound.

3. Circulation velocity – blood transport time on circulation circle. Norma: 14-20 sec.

Investigative methods: radioactive.

Blood pressure – force whith which blood presses onto vessel walls.

It depends on:

a) heart activity,

b) vessels resistance,

c) their diameter,

4. their length,

5. blood viscosity.

Maximal (systolic) pressure is registrated during heart systole. Its size is equal to 100-130 mm merc col (on brachial artery). There is a tendency to this pressure increasing during last years of practically healthy children even of school age. Its level depends mainly on heart activity.

Minimal (dyastolic) pressure is characterized by size registrated during dyastole. Norma: 65-90 mm merc col. Vascular wall tone is a dominant factor determining this pressure.

Pulse pressure – matematic difference between systolic and dyatolic pressure level. Its maximal size is in arteries near heart. The farther from heart the pressure pulse difference is decreased and beginning from arterioles it disappears.

Middle-dynamic pressure – expresses energy with which blood is moved, it provides blood movement through vessels and it is the average resulting size for all pressure fluctuations (oscillations) alongside all vascular system. Its level is less than systolic but more than dyastolic. Norma: 90-100 mm merc col.

Pressure changings in course of transport through all vessels:

• aorta – 120-130 mm merc col.;

• arteries – 100-120 mm merc col.;

• arteries- 40-80 mm merc col.;

• capillaries – 20-40 mm merc col.;

• veins – 5-10 mm merc col.;

• vena cava - up to 0 mm merc col.

Arterial pulse – or push, arterial wall fluctuation caused by systolic pressure increasing in arteries. Pulse wave appears in aorta when pressure is sharply increased in it and its wall is stretched. This wave is spread with velocity 3-15 m per second from aorta to arterioles. It may be registrated on large, superficially located arteries, by palpation or graphically (sphygmogram). At palpation its necessary to perform on both hands simultaneousely (hands must be at heart level) in one and the same patient location from initial investigation. If one can not determine any difference further pulse investigation should be performed on one hand (at pulse difference on both hands pulse is called different). Different pulse may be diagnostic sign of mitral valve stenosis, aortal aneurisme.

One can differentiate on sphygmogram:

• anacrote (it corresponds to ventricles systole) – curve ascent (rising);

• catacrote (it corresponds to blood slow exile from ventricules in its beginning, rest part – ventricules dyastole) – curve descent (falling down, drop);

• dycrote – there is dycrotic ascent on catacrote, it corresponds to blood return to heart during dyastole ans its shock to semicircular valves.