physiology 1-bp-registration-regulation
TRANSCRIPT
BP REGISTRATION & REGULATION. PECULIARITIES OF REGIONAL BLOOD SUPPLY
Lecturer MD, Ph.D. Angelika V. Ivasenko
Laws of haemodynamics Pressure difference is the moving
force in blood flow Blood flows from high pressure to low
pressure Pressure is created by ventricles
contraction
P=Q·R Q is minute volume of blood flow, it is
determined by heart work Q= HR · SV, HR- heart rate, SV –
stroke volume R is resistance of the vessel to blood
flow R, depends mainly on vessel radius
Functional classification of blood vessels (by Folkov) Buffer (aorta) Precapillary resistance vessels
(arteries,arterioli) Exchange vessels (capillaries) Postcapillary resistance vessels
(venuli,small veins) Arterio-venous anastomosis Volume vessels (big veins)
Linea velocity of blood flow in different parts of circulatory system
Aorta arteries arterioli capillaries veins
Pressure changes in different parts of circulatory system
Aorta arteries arterioli capillaries venuli,veins vena cava
Methods of BP registration
DIRECT-registeringpressure in the vessel
INDIRECT-registering
pressure in the cuff of
sphygmomanometer
PALPATORY(RIVA-ROCCHI)
AUSCULTATORY (KOROTKOV)
WAVES on BP curve Waves of the 1st type- pulse waves Waves of the 2nd type-respiratory
waves Waves of the 3rd type-changing in the
tone of vasomotor centre
Indirect methods of BP registration Pressure is measured in the cuff, not
in the vessel Based on the III law of Newton we
consider it to be same (or almost same as in the vessel)
Riva-Rocchi method allows to measure systolic BP only
Korotkov’s method allows to measure both systolic & diastolic BP
Continuous blood flow Volume of blood vessels & heart
chambers should correlate with the volume of blood flow
Left & right heart should work in correlation
Basilar tone of the vessels registered without any nervous
& hormonal influences Has 2 components:1. Myogenic2. Tonic impulses from vasomotor
centre (1-3 per sec)
Vasoconstriction influences Sympathetic fibres (alfa-adrenoreceptors) Humoral influences 1. Renin-angiotensin2. Adrenalin3. serotonin
Vasodilation influences Sympathetic fibres (beta-adrenoreceptors) Sympathetic fibres (cholinoreceptors) Paraympathetic fibres (n. pudendus, chordae
tympani) Humoral influences:1. Hystamine2. Bradikinin3. Prostaglandines Metabolic influences (lactate, adenosine, pH)