GENERAL PRINCIPLES OF GENERAL PRINCIPLES OF CIRCULATIONCIRCULATION

FUNCTION OF CIRCULATIONFUNCTION OF CIRCULATION

1.OXYGEN AND NUTRIENT SUPPLY.1.OXYGEN AND NUTRIENT SUPPLY.

2.REMOVE WASTE PRODUCTS.2.REMOVE WASTE PRODUCTS.

3.REGULATION OF HEAT LOSS.3.REGULATION OF HEAT LOSS.

4.BODY DEFENCE MECHANISM4.BODY DEFENCE MECHANISM..

BLOOD FLOWBLOOD FLOW

BLOOD FLOWS FROM BLOOD FLOWS FROM HEART TO OTHER HEART TO OTHER PARTS AND COME PARTS AND COME BACK DUE PRESSURE BACK DUE PRESSURE GRADIENT.BLOOD GRADIENT.BLOOD FLOW TO AORTA IS FLOW TO AORTA IS PULSATILE BUT TO PULSATILE BUT TO SMALL VESSELS IS SMALL VESSELS IS CONTINUOUS DUE TO CONTINUOUS DUE TO WINDKESSEL EFFECT.WINDKESSEL EFFECT.

PUL.CPUL.C SYS.CSYS.C

LALA 7-8/07-8/0 RARA 4-6/04-6/0

LVLV 120/120/00

RVRV 25/025/0

AORAOR 120/120/8080

PAPA 25/825/8

ARTART 6060 ARTART 1010

MAMA 1010 MAMA 88

VENVEN 1010 VENVEN 55

VCVC 22 P.VP.V 22

ORGANIZATION OF VASCULAR SYSTEMORGANIZATION OF VASCULAR SYSTEM

1.WINDKESSEL VESSEL.1.WINDKESSEL VESSEL.

2.RESISTANCE VESSEL.2.RESISTANCE VESSEL.

3.EXCHANGE VESSEL.3.EXCHANGE VESSEL.

4.CAPACITANCE VESSEL.4.CAPACITANCE VESSEL.

5.SHUNT VESSELS.5.SHUNT VESSELS.

WIND KESSELWIND KESSEL

DISTENDS DURING SYSTOLE.DISTENDS DURING SYSTOLE.

BLOOD FLOWS DUE TO PROPELLING FORCE OF BLOOD FLOWS DUE TO PROPELLING FORCE OF THE HEART.THE HEART.

RELAXES DURING DIASTOLE.RELAXES DURING DIASTOLE.

BLOOD FLOWS DUE TO RECOIL OF AORTA AND BLOOD FLOWS DUE TO RECOIL OF AORTA AND LARGE VESSELS KNOWN AS WINDKESSEL EFFECT.LARGE VESSELS KNOWN AS WINDKESSEL EFFECT.

WITH AGE THIS EFFECT DECREASES SBP WITH AGE THIS EFFECT DECREASES SBP INCREASES,DBP DECREASES,PP INCREASES. INCREASES,DBP DECREASES,PP INCREASES. DEFECTIVE PERFUSION OCCURS AT PERIPHERY.DEFECTIVE PERFUSION OCCURS AT PERIPHERY.

RESISTANCERESISTANCE

OFFER RESISTANCE TO BLOOD FLOW INTO CAPILLARIES. OFFER RESISTANCE TO BLOOD FLOW INTO CAPILLARIES. (ARTERIOLES,META-ARTERIOLES,PRE CAPILLARY (ARTERIOLES,META-ARTERIOLES,PRE CAPILLARY SPHINCTERS).ARTERIOLES OFFER MAXIMUM RESISTANCE .MAINSPHINCTERS).ARTERIOLES OFFER MAXIMUM RESISTANCE .MAIN SITE FOR PERIPHERAL RESISTANCE.SITE FOR PERIPHERAL RESISTANCE.

RESISTANCE-R IS INVERSELY PROPORTIONAL TO r 4.RESISTANCE-R IS INVERSELY PROPORTIONAL TO r 4.

SLIGHT CHANGE IN RADIUS – HUGE CHANGE IN RESISTANCE.SLIGHT CHANGE IN RADIUS – HUGE CHANGE IN RESISTANCE.

BLOOD VESSELS HAVE BLOOD VESSELS HAVE 1.MYOGENIC CONTROL.1.MYOGENIC CONTROL. 2.SYMPATHETIC CONTROL.2.SYMPATHETIC CONTROL.

EXCHANGEEXCHANGE

CAPILLARIES ARE THE MAIN EXCHANGE VESSELS. CAPILLARIES ARE THE MAIN EXCHANGE VESSELS. THEY ALLOW EASY EXCHANGE OF OXYGEN AND THEY ALLOW EASY EXCHANGE OF OXYGEN AND NUTRIENTS TO ALL TISSUES.NUTRIENTS TO ALL TISSUES.

BLOOD FLOW TO MANY ORGANS IS ACCORDING TO BLOOD FLOW TO MANY ORGANS IS ACCORDING TO THEIR IMPORTANCE.THEIR IMPORTANCE.

BLOOD FLOW IS MAX TO LIVER IN ML/MINUTE(1500)BLOOD FLOW IS MAX TO LIVER IN ML/MINUTE(1500)

BLOOD FLOW IS MAX TO KIDNEY IN BLOOD FLOW IS MAX TO KIDNEY IN ML/100GM/MINUTE (400ML)ML/100GM/MINUTE (400ML)

DURING VASODILATION, BLOOD FLOW TO SKIN AND DURING VASODILATION, BLOOD FLOW TO SKIN AND SKELETAL MUSCLES INCREASES BY 20 TIMES.SKELETAL MUSCLES INCREASES BY 20 TIMES.

MORPHOLOGY OF CAPILLARIESMORPHOLOGY OF CAPILLARIES

1.ONE LAYER OF ENDOTHELIUM.1.ONE LAYER OF ENDOTHELIUM.

2.LENGTH-500MICRO METER.DIA-6 MICRO METER.2.LENGTH-500MICRO METER.DIA-6 MICRO METER. CSA-30MIC-MET-SQ TOTAL NUMBER-50000 CSA-30MIC-MET-SQ TOTAL NUMBER-50000

MILLION.MILLION.

TYPESTYPES- 1. CONTINUOUS-INTER CELLULAR AREA 10NM.MOST - 1. CONTINUOUS-INTER CELLULAR AREA 10NM.MOST COMMON TYPE.ONLY EXCHANGE OF FLUID OCCURS.COMMON TYPE.ONLY EXCHANGE OF FLUID OCCURS.

2.FENESTRATED-CONTAINS PORES.PORE SIZE-20-100NM.2.FENESTRATED-CONTAINS PORES.PORE SIZE-20-100NM. EX-RENAL GLOMERULI,INTESTINAL VILLI.EX-RENAL GLOMERULI,INTESTINAL VILLI.

3.DISCONTINUOUS-LARGE GAPS.EX-BONE 3.DISCONTINUOUS-LARGE GAPS.EX-BONE MARROW,LIVER,SPLEEN.MARROW,LIVER,SPLEEN.

CAPACITANCECAPACITANCE

THESE VESSELS CAN ACCOMMODATE LARGE VOLUME OF THESE VESSELS CAN ACCOMMODATE LARGE VOLUME OF

BLOODBLOOD WITHOUT INCREASING MUCH PRESSURE.WITHOUT INCREASING MUCH PRESSURE.

EX- VEIN AND THE VENULES.EX- VEIN AND THE VENULES.

AT REST 54% BLOOD REMAINS IN VEINS.THEY HAVE ALSO AT REST 54% BLOOD REMAINS IN VEINS.THEY HAVE ALSO MYOGENIC TONE.MYOGENIC TONE.

GRAVITY HAS EFFECT ON IT – LYING TO STANDING POSTUREGRAVITY HAS EFFECT ON IT – LYING TO STANDING POSTURE

PERIPHERAL PULLING OF BLOOD- DIZZINESS - PERIPHERAL PULLING OF BLOOD- DIZZINESS - POSTURAL POSTURAL HYPOTENSION.HYPOTENSION.

NORMAL CVP-4 TO 6 MM HG. PVP – 10 MM HG. NORMAL CVP-4 TO 6 MM HG. PVP – 10 MM HG.

SHUNTSHUNT

SYNONYM-THOROUGHFARE VESSELS.SYNONYM-THOROUGHFARE VESSELS.

THE META ARTERIOLES SHUNT WITH THE VENULES THE META ARTERIOLES SHUNT WITH THE VENULES BYPASSING THE CAPILLARIES.EX-VESSELS IN SKIN,LIPS BYPASSING THE CAPILLARIES.EX-VESSELS IN SKIN,LIPS TOES,EAR LOBULES,PALM AND FINGERS.TOES,EAR LOBULES,PALM AND FINGERS.

THE WALL HAS STRONG MUSCULAR COAT WITH RICH THE WALL HAS STRONG MUSCULAR COAT WITH RICH SYMPATHETIC NERVE SUPPLY.SYMPATHETIC NERVE SUPPLY.

WHEN THEY CONTRACT-DECREASE BLOOD SUPPLY AND WHEN THEY CONTRACT-DECREASE BLOOD SUPPLY AND WHEN THEY DILATE INCREASE BLOOD SUPPLY.THEY ARE OF WHEN THEY DILATE INCREASE BLOOD SUPPLY.THEY ARE OF MUCH USE DURING THERMAL STRESS.MUCH USE DURING THERMAL STRESS.

HEAT-DILATES-INCREASE HEAT LOSS.HEAT-DILATES-INCREASE HEAT LOSS. COLD-CONSTRICT-DREASED HEAT LOSS.COLD-CONSTRICT-DREASED HEAT LOSS.

PHYSICS OF CIRCULATIONPHYSICS OF CIRCULATION

FLOW VELOCITY IS INVERSELY PROPORTIONAL TO CROSS FLOW VELOCITY IS INVERSELY PROPORTIONAL TO CROSS SECTIONAL AREA.SECTIONAL AREA.

FLOW (F)=(P1-P2)/R ,P1-P2 = PRESSURE DIFFERENCE FLOW (F)=(P1-P2)/R ,P1-P2 = PRESSURE DIFFERENCE BETWEEN TWO ENDS OF THE VESSEL AND R IS THE BETWEEN TWO ENDS OF THE VESSEL AND R IS THE RESISTANCE.RESISTANCE.

R= (P1-P2) / F . AT REST PRESSURE AT ARTERIAL END – R= (P1-P2) / F . AT REST PRESSURE AT ARTERIAL END – PRESSURE AT VENOUS END = 100 MM HG AND BLOOD FLOW PRESSURE AT VENOUS END = 100 MM HG AND BLOOD FLOW =100 ML/SEC , R = 100/100 = 1MMHG/ML/SEC.=1 PRU.=100 ML/SEC , R = 100/100 = 1MMHG/ML/SEC.=1 PRU.

DURING MAX VASOCONSTRICTION PR = 4 PRU AND DURING DURING MAX VASOCONSTRICTION PR = 4 PRU AND DURING MAX VASODILATION PR = 0.2 PRU.MAX VASODILATION PR = 0.2 PRU.

TYPES OF BLOOD FLOWTYPES OF BLOOD FLOW

FLOW TYPEFLOW TYPE LAMINARLAMINAR TURBULANTTURBULANT

LAYERSLAYERS MANYMANY NO LAYERSNO LAYERS

AREAAREA MOST PARTSMOST PARTS LARGE LARGE ARTERIESARTERIES

SOUNDSOUND SILENTSILENT NOISYNOISY

RENOLDS RENOLDS NUMBERNUMBER

< 2OOO< 2OOO >2000 >2000