L. Pressure and Perfusion in the Heart1. Pulmonary circulationa) Low pressure= 15/8mmHgb) High Perfusion –blood flow from right heart is 5L/min2. Systemic circulationa) High pressure = 120/80 mmHgb) High perfusion – blood flow from the left heart (5L/min)3. Arteries – smooth muscle  are elastic forgiving for high pressure4. Veins- smooth muscle built for low pressure5. Circulation of the blood and continuous forward pattern from the heart6. Pressure = independent variablea) 3 types of pressure (can be manipulated with any of these 3)(1) cardiac output (systolic pressure) heart rate and stroke volume  driving pressure(2) peripheral vessel ”resistance”(3) hemodynamic pressure – blood’s volume and density  also is resistive pressureb) systolic pressure – driving pressure, and must always be present for blood to flowc) diastolic pressure – always present in the backgroundd) blood always moves along the pressure gradient, starts in artery that is high pressure and moves to low pressure veinse) not all capillaries receive the same volume of blood – this deals with perfusion – different resistance in arteries causes different volumes into the capillariesf) PRESSURE drives PERFUSION7. Perfusion- dependent variablea) dependent on(1) blood flow volume ml/min(2) Blood flow speed (distance/ time)8. Goal of circulation adequate and adjustable blood delivery meeting individual tissue demandsa) requirements:(1) closed system(2) adequate volume(3) Energy to move bloodM. Blood Flow Physiology1. The previous pressure must be greater than the second pressure in the circulation (must follow pressure gradent)2. Need strong, elastic walls in great arteries so blood doesn’t just sit therea) Blood that is left behind creates a resistive forceb) Blood interacting with vessels provides resistive pressurec) You can raise resistive pressure to blood flow to distribute blood elsewhere down streamd) Resistance is dependent on radius of the vein or artery and blood volume / density (viscosity)3. Measuring blood pressurea) when pumping air in to close the artery, only pump 10 mL above what you think should be normal, so that you do not hurt the arteryb) the stethoscope should be downstream of the artery block and you must listen for the first Korotkoff sound(1) 1st Korotkoff sound is systolic(2) 2nd sound is diastolic4. mean arterial pressure= mean pressure near the hearta) average pressure through the pulse and must always exceed diastolic pressure to moveb) the closer diastolic and systolic pressure get to each other, the slower blood will movec) all three blood pressures contribute to and ultimately regulate mean arterial pressured) how to vary mean arterial pressure (MAP)(1) Radius of the vessel(a) stimulate the muscle to create a contraction and stimulate vasoconstriction causing an increase in resistance(b) vasodilatation will decrease resistance(c) Rissole’s law: Resistance = 1/ (radius)4(i) little change in arterial radius= HUGE change in resistance and therefore diastolic pressure(d) raise diastolic pressure by atherosclerosis by eating poorly(2) Increase resistance- increasing resistance makes heart work harder(a) 120/85 = prehypertension(b) 139/ 89 = hypertensive, only slightly on the first level, and then it can progress to 210/120(c) corrections to resistance(i) cannot vasodialate because then everything will vasodilate in the body and lead to hypotension(ii) decrease in flow, decrease in rate, and volume will acidify the body and lead to clots(iii) only way to decrease resistive pressure is to loose water(a) therefore need to pee  diuretic therapy(d) Increase in resistance causes a decrease vessel radius, decrease in blood volume, increase in pressure, increase in speed, increases EDV that ultimately increases stroke volume5. Unequal Blood Flow – Brain adjusts blood flow (distal control)a) oxygen demand in tissue determines amount of blood goes thereb) Brain and kidney are the only organs that can not have fluctuating blood flowc) Brain can adjust blood flow with hormones(1) decrease amount of epinephrine (para/sympathetic activity) will increase blood flow(2) Angiotension: Renin-angiotension-aldosterone method(3) Kidney receives a decrease in blood flow, produces Rennin and prohormone produced in liver, Angiotensinogen is made into Angiotensin I by rennin and this doesn’t do much but when converted to Angiotensin II by Rennin  this causes vasoconstriction and Aldosterone release, which increases Na+ levels that increase blood volume(a) Angiotension converting enzyme (ACE inhibitor) is an inhibitor of Angiotension II or the Rennin inhibitor will inhibit thisd) Local control of blood flow(1) vasoconstriction – decreases temp, increases O2, decrease in CO2(2) vasodialation- decreases O2 or increases CO2 increase in NO production, and increase in temperaturee) Volume control(1) Aldosterone  (indirect regulator control) controls with sodium(2) vasopressin  (direct regulator) hypothalamus starts and then kidney is stimulated and water is lost of gained (if increase vasopressin, increase water retention)Lecture 20 Outline of Last Lecture I. Heart Sounds J. Pressure/ Volume LoopK. Cardiac Output Outline of Current Lecture L. Pressure and Perfusion M. Blood Flow PhysiologyCurrent Lecture L. Pressure and Perfusion in the Heart 1. Pulmonary circulationa) Low pressure= 15/8mmHg b) High Perfusion –blood flow from right heart is 5L/min2. Systemic circulationa) High pressure = 120/80 mmHg b) High perfusion – blood flow from the left heart (5L/min)3. Arteries – smooth muscle  are elastic forgiving for high pressure 4. Veins- smooth muscle built for low pressure5. Circulation of the blood and continuous forward pattern from the heart 6. Pressure = independent variablea) 3 types of pressure (can be manipulated with any of these 3)(1) cardiac output (systolic pressure) heart rate and stroke volume  driving pressure (2) peripheral vessel ”resistance” (3) hemodynamic pressure – blood’s volume and density  also is resistive pressure These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. BY 116 1st Editionb) systolic pressure – driving pressure, and must always be present for blood toflow c) diastolic pressure – always present in the backgroundd) blood always moves along the pressure gradient, starts in artery that is