This Week in PBS&DBlood VesselsVessel AnatomyBlood Pressure throughout Vascular SystemSystolic vs. Diastolic vs. Mean Arterial PressurePressure GradientPressure GradientSkeletal Muscle PumpVelocity of FlowRelationship of CSA to Velocity of FlowFactors that Increase Blood PressureFactors that Increase Blood PressureCardiovascular Center in MedullaAutonomic Intervention of the HeartShockShockBloodPlasmaFormed ElementsRed Blood CellsWhite Blood CellsSignificance of White Blood Cell CountsPlateletsPlatelet Plug FormationHomeworkPrinciples of Biomedical Systems & DevicesPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Principles of Biomedical Systems & DevicesLecture 9HemodynamicsDr. Maria TahamontPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404This Week in PBS&D HemoDynamicsª Blood vesselsª Pressure gradientª Factors affecting blood pressure and homeostasis of blood pressureª Shockª Blood and its components Measuring Blood Pressureª Direct measurement of BPª Dynamic properties of the direct measurement catheter systemsª Heart soundsª Indirect measurements of the BP• Auscultation and osscilometric methodsPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Blood Vessels Arteries – carry blood away from the heart Arterioles – deliver blood to capillary beds Capillaries – vessels of exchange Venules – collect blood from capillary beds Veins – return blood to the heartPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Vessel AnatomyPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Blood Pressure throughout Vascular SystemPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Systolic vs. Diastolic vs. Mean Arterial PressureMean Arterial Blood Pressure (MABP) = Diastolic BP + 1/3 (systolic BP– diastolic BP)This can only be computed by integrating the above characteristic. Note that MABP is slightly less then the average BP due to shorter time involved in systole.~PBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Pressure Gradient Remember blood flow follows the pressure gradient The pressure is greatest in the arteries which receive the bloodunder pressure from the ventricles Pressure drops along the vascular tree because of increased cross sectional area and distance from the ventricle Veins are very low pressure vessels, blood flow easily into themPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Pressure Gradient The atria have the lowest pressure so blood will flow from the veins to the atria Need external pressure to get blood in distal veins back toward heartª Skeletal muscle pumpª Negative thoracic pressure caused by respirationPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Skeletal Muscle PumpPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Velocity of Flow Velocity of flow is inversely related to the cross sectional area (CSA) Velocity is slowest where the CSA is the largest We are talking about total CSA, not the CSA of individual vesselsPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Relationship of CSA to Velocity of FlowPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Factors that Increase Blood Pressure Anything that increases cardiac output increases blood pressure Anything that increases blood viscosity increases blood pressure Anything that increases vascular resistance increases blood pressure Anything that causes sympathetic signals from the autonomic nervous systems increases blood pressurePBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Factors that Increase Blood PressurePBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Cardiovascular Center in MedullaPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Autonomic Intervention of the HeartPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Shock Shock is a failure of the cardiovascular system to supply enough oxygen and nutrients for the metabolic needs of the body. 4 typesª Hypovolemic – blood lossª Cardiogenic – pump failsª Vascular – inappropriate vasodilationª Obstructive – obstruction of flowPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404ShockPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Blood Functions: transportation, regulation, protection Slightly viscous, warm, slightly basic Total volume approximately equal to 8% of body weight (liters tokilograms) Two major portionsª Plasma – fluid, ~55%ª Formed Elements – solids, ~45%PBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404PlasmaPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Formed ElementsPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Red Blood Cells Erythrocytes Packed with hemoglobin which is the protein carries oxygen 7-8 microns in diameter Biconcave disk No nucleus at maturity 4.5 to 5.5 million/ microliter Carry oxygen from lung to working tissuePBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404White Blood Cells Leukocytes Protectionª Phagocytes, produce antibodies, recognize foreign agents 5 different typesª Neutrophils, eosinophils, basophils, lymphocytes, monocytesª Numbers vary with type, generally 5,000 to 10,000 per microliterPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Significance of White Blood Cell CountsPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Platelets Not cells, cell fragments Play vital role in blood clottingªPlatelet adhesionªPlatelet activation (release reaction)ªPlatelet aggregationªPlatelet plug formationPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404Platelet Plug FormationPBS&D – Fall 2004 – Polikar http://engineering.rowan.edu/~polikar/CLASSES/ECE404HomeworkRead Chapter 7: Blood Pressure and Sound for Thursday. There may be a (comprehensive)