FISIOLOGIA CARDIOVASCULAR Robson A S Santos HEMODIN MICA

FISIOLOGIA CARDIOVASCULAR Robson A. S. Santos

HEMODIN MICA DA CIRCULAÇÃO PERIFÉRICA

In 1627, William Harvey was able to confirm his observation that the blood circulates throughout the body, which he inferred from the structure of the venal valves. The following year, in Exercitatio Anatomica, he published these conclusions as well as a description of the heart as a mechanical pump In 1651, Harvey published the concept that all living things originate from eggs. Harvey believed that in principle organisms could be spontaneously generated, and that the process was one of the self-generation of a complicated machine. In 1661, Marcello Malpighi, in De pulmonibus, reported his observation of blood movement through the capillaries. He is also noted for his studied of the glands. In 1733, Hales measured blood pressure. In 1738, Daniel Bernoulli, in Hydrodynamica, asserted the principle that as the speed of a moving fluid increases, the pressure within the fluid decreases. In the process of determining this, he invented the 'molecular theory of gases, ' now known as the 'kinetic theory of gases, ' which introduced the notion that the gas particles were moving around rapidly and that a gas's temperature is a function of the average speed of its particles.

PRINCIPAIS FUNÇÕES DO SISTEMA CIRCULATÓRIO Transporte e distribuição de substâncias essenciais para os tecidos. n Remoção de produtos do metabolismo. n Ajustar o suprimento de oxigênio e nutrientes em diferentes estados fisiológicos n Regulação da temperatura corporal n Comunicação humoral n

O CIRCUÍTO BOMBA TÚBULOS DISTRIBUIDORES TÚBULOS COLETORES VASOS DE TROCA

Pressure Drop in the Vascular System ELASTIC TISSUE MUSCLE MEAN PRESSURE LARGE ARTERIES LARGE SMALL ARTERIES ARTERIOLES CAPILLARIES VENULES &VEINS SMALL INSIDE DIAMETER LARGE

Distribuição do Sangue no Sistema Circulatorio 67% VEIAS SIST. /VENULAS n 5% CAPILARES SISTÊMICOS n 11% ARTÉRIAS SISTÊMICAS n 5% VEIAS PULMONARES n 3% ARTÉRIAS PULMONARES n 4% CAPILARES PULMONARES n 5% ÁTRIOS/VENTRICULOS n

Organização do Sistema Circulatório CIRCUITOS EM SÉRIE E EM PARALELO

HEMODIN MICA VELOCIDADE, FLUXO, PRESSÃO n FLUXO LAMINAR n LEI DE POISEUILLE n RESISTÊNCIA(SERIE-PARALELO) n FLUXO TURBILHONAR E NÚMERO DE REYNOLD n

PRESSÃO HIDROSTÁTICA 136 cm 0 100 200 0 100 0 P = Pressão mm. Hg p = densidade g = gravidade h = altura 200 P=pxgxh 100 mm. Hg 136 cm 0 100 200 0 0 100 200

CONCEITOS IMPORTANTES VELOCIDADE = DIST NCIA / TEMPO V = D / T FLUXO = VOLUME / TEMPO Q = VL / T VELOCIDADE -FLUXO- ÁREA V = Q / A

ENERGIA DE UM FLUÍDO ESTÁTICO VS EM MOVIMENTO ENERGIA TOTAL= POTENTIAL + CINÉTICA ET = EP + EC FLUÍDO EM REPOUSO (HIDROSTÁTICA ) FLUÍDO EM MOVIMENTO (HYDROSTÁTICA + HIDRODIN MICA)

VELOCIDADE E PRESSÃO 0 0 100 200

ÁREA DE SECÇÃO TRANSVERSAL E VELOCIDADE A= 2 cm 2 Q=10 ml/s a V= 5 cm/s 10 cm 2 b 1 cm/s V=Q/A 1 cm 2 c 10 cm/s

LEI DE POISEUILLE Fluxo em Tubos Cilíndricos Rigídos (FLUXO)Q = DIFERENÇA DE PRESSÃO 4 (Pi - Po) r 8ηL VISCOSIDADE COMPRIMENTO RAIO

POISEUILLE’S LAW GOVERNING FLUID FLOW(Q) THROUGH CYLINDRIC TUBES

RESISTÊNCIA AO FLUXO NO SISTEMA CARDIOVASCULAR CONCEITOS BÁSICOS Rt = R 1 + R 2 + R 3…………. RESISTÊNCIAS EM SÉRIE 1/Rt = 1/R 1 + 1/R 2 + 1/R 3…. RESISTÊNCIAS EM PARALELO R 1 SÉRIE R 1 R 2 R 3 PARALELO R 2 R 3

RESISTÊNCIA AO FLUXO NO SISTEMA CARDIOVASCULAR O QUE REALMENTE OCORRE NO SCV? BAIXA R ALTA R BAIXA R ARTÉRIAS ARTERÍOLAS CAPILARES

Teorema de Bernoulli para um fluxo constante em um leito fechado. A soma da Energia de Pressão, Energia Cinética e Energia Potencial em um determinado ponto do leito vascular é igual a soma dessas Energias em um outro ponto do mesmo leito vascular.

FLUXO LAMINAR VS FLUXO TURBILHONAR O Número de REYNOLD FLUXO LAMINAR FLUXO TURBILHONAR Nr = p. Dv/ n p = densidade D = diâmetro v = velocidade laminar = 2000 ou inferior n = viscosidade

SISTEMA ARTERIAL n COMPLACÊNCIA n PRESSÃO ARTERIAL n PRESSÃO DE PULSO n MEDIDA DE PRESSÃO

THE END

THE CONCEPT OF THE HYDRAULIC FILTER SYSTOLE DIASTOLE COMPLIANT RIGID

O 2 CONSUMPTION (ml. O 2/100 g/beat) EFFECTS OF PUMPING THROUGH A RIGID VS A COMPLIANT DUCT 0. 1 PLASTIC TUBING NATIVE AORTA 0 5 STROKE VOLUME (ml) 15

% INCREASE IN VOLUME STATIC P-V RELATIONSHIP IN THE AORTA PRESSURE (mm. Hg)

ELASTIC MODULUS OR ELASTANCE Ep = P / D/D ELASTANCE P V Ep= ELASTIC MODULUS D= MAX. CHANGE IN AORTIC DIAMETER. D= MEAN AORTIC DIAM. COMPLIANCE V P EP IS INVERSELY PROPORTIONAL TO C

MEAN ARTERIAL PRESSURE (MAP) REMEMBER OHMS LAW? CARDIAC OUTPUT PERIPHERAL RESISTANCE INSTANTANEOUS INCREASE STEADY STATE INCREASE

ARTERIAL PRESSURE (mm. Hg) EFFECT OF COMPLIANCE ON MAP Pa = Qh - Qr / Ca SMALL Ca LARGE Ca INCREASE CARDIAC OUTPUT TIME Qh- inflow (CO) Qr- outflow Ca- Compliance Pa- MAP

PULSE PRESSURE STROKE VOLUME COMPLIANCE V 4 VB VOLUME V 3 V 2 VA V 1 PA P 2 P 3 PB P 4 PRESSURE

PULSE PRESSURE EFFECTS OF: COMPLIANCE TOTAL PERIPHERAL RESISTANCE TPR

COUPLING OF THE HEART AND BLOOD VESSELS VASCULAR FUNCTION CURVE HOW CARDIAC OUTPUT REGULATES CENTRAL VENOUS PRESSURE CARDIAC FUNCTION CURVE HOW CENTRAL VENOUS PRESSURE (PRELOAD) REGULATES CARDIAC OUTPUT

VASCULAR FUNCTION CURVE CENTRAL VENOUR PRESSURE (mm. Hg) HOW CHANGES IN CARDIAC OUTPUT INDUCE CHANGES IN CENTRAL VENOUS PRESSURE? 8 Pmc B VASCULAR FUNCTION CURVE A -1 0 8 CARDIAC OUTPUT (L/min)

8 VASCULAR FUNCTION CURVE N O SI U SF E L N G A A A H TR RM RR O NO EM H CENTRAL VENOUR PRESSURE (mm. Hg) HOW BLOOD VOLUME AND VENOMOTOR TONE CHANGE THE VASCULAR FUNCTION CURVE? -1 0 8 CARDIAC OUTPUT (L/min)

8 VASCULAR FUNCTION CURVE VA SO DI VA LA NO RM AL TI ON ON TI C RI ST N CO SO CENTRAL VENOUR PRESSURE (mm. Hg) TOTAL PERIPHERAL RESISTANCE AND THE VASCULAR FUNCTION CURVE. -1 0 8 CARDIAC OUTPUT (L/min)

CARDIAC OUTPUT (L/min) THE CARDIAC FUNCTION CURVE CENTRAL VENOUS PRESSURE (mm. Hg)

CARDIAC OUTPUT (L/min) EFFECTS OF SYMPATHETIC STIMULATION ON THE CARDIAC FUNCTION CURVE CENTRAL VENOUS PRESSURE (mm. Hg)

HOW BLOOD VOLUME AND PERIPHERAL RESISTANCE CHANGE THE CARDIAC FUNCTION CURVE? CARDIAC OUTPUT (L/min) VOLUME CENTRAL VENOUS PRESSURE (mm. Hg) RESISTANCE

CARDIAC OUTPUT (L/min) THE CARDIAC FUNCTION CURVE IN HEART FAILURE CENTRAL VENOUS PRESSURE (mm. Hg)

HEART - BLOOD VESSELS COUPLING MORMAL FUNCTION PUMP VEINS ARTERIES Qh CPV=2 mm. Hg=Pv 5 L/min COMPLIANCES Cv = 19 Ca Cv>>>>Ca Qr PERIPHERAL R= Pa - Pv / Qr R = 20 mm. Hg/L/min 5 L/min Pa MPA=102 mm. Hg

CARDIAC ARREST! INMEDIATE EFFECT FLOW STOPS HERE PUMP VEINS ARTERIES Qh 0 L/min Pa CPV=2 mm. Hg=Pv 5 L/min FLOW CONTINUES HRE TRANSFER ART-->VEINS Qr R = 20 mm. Hg/L/min Qr= Pa - Pv/20 Qr CONTINUES AS LONG AS A PRESSURE GRADIENT IS SUSTAINED

CARDIAC ARREST STEADY STATE FLOW STOPPED PUMP VEINS ARTERIES Qh 0 L/min Pa = 7 mm. Hg Pv = 7 mm. Hg = MEAN CIRCULATORY PRESSURE OR Pmc 5 mm. Hg FLOW STOPPED 0 L/min Qr Qr = 0 ( NO Pa - Pv DIFFERENCE) 95 mm. Hg

WE START PUMPING! INMEDIATE EFFECT FLOW STARTS SOME VENOUS BLOOD PUMP VEINS ARTERIES Qh 1 L/min Pa = 7 mm. Hg Pv = 7 mm. Hg NO FLOW HERE YET 0 L/min Qr

FLOW RETURNS AT Qr AT THE NEW Qh PUMP VEINS ARTERIES Qh 1 L/min Pa = 26 mm. Hg Pv = 6 mm. Hg FLOW STARTS 1 L/min Qr R = 20 mm. Hg Qr = Pa - Pv / 20 = 1 L/min