BSNC 1000 Module 4 Perfusion Class 1-Student PDF

Adobe Stock Module 4 Perfusion BSNC 1000 Class 1: Concept Introduction 1 Learning Outcomes 1. Discuss the concept of perfusion and the normal physiological processes that determine tissue pe...

Adobe Stock Module 4 Perfusion BSNC 1000 Class 1: Concept Introduction 1 Learning Outcomes 1. Discuss the concept of perfusion and the normal physiological processes that determine tissue perfusion. 2. Discuss the signs and symptoms of optimal and impaired perfusion. 3. Explain the factors that influence cardiac output and peripheral vascular resistance in order to understand the determinants of blood pressure. 4. Explore the theory behind measuring blood pressure and factors that impact blood pressure readings. 2 Components of a Physiological Concept Clinical Definition Exemplars Interrelated Scope Concepts Risk Normal Factors Process Variations & Consequences 3 Definition Perfusion is the flow of blood through the cardiovascular system. Purpose: Delivers oxygen and nutrients to tissues and removes cellular waste products. 4 Components of a Cardiovascular System Name Property Function Pump: Rhythmic Heart Pressure generator contraction Outgoing pipes: Arterial system Pressure reservoir Elastic vessels Conveyor belt: Exchange gases, deliver Capillary network Exchange vessels nutrients and remove wastes Incoming pipes: Venous system Volume reservoir Compliance vessels 5 Brainstorm Why are the arterial vessels described as elastic and a pressure reservoir? Why are the venous vessels described as compliant and a volume reservoir? 6 Scope of Perfusion Ischemia Infraction 8 Central vs Tissue Perfusion Central Perfusion The flow of blood through the heart Tissue (Local) Perfusion The flow of blood through target tissues 9 Central Perfusion Central perfusion is determined by cardiac output. Normal Range: 5000-6000 ml/min Normal Range: Normal Range: 60-100 beats/min 50-100 ml/beat 10 Brainstorm What physiological factors regulate heart rate? What physiological factors regulate stroke volume? 11  Central Perfusion Central perfusion is determined by cardiac output. Cardiac Output (CO) Sympathetic nerves ↑ Preload and afterload Parasympathetic nerves ↓ Heart Rate Stroke Volume (HR) (SV) Hormones Contractility (N & NE) ↑ 12 Tissue Perfusion Tissue perfusion is determined by systemic vascular resistance (SVR). the impediment to blood flow 13 Tissue Perfusion SVR is influenced by: Blood vessel radius most powerful, adjustable and swift control on SVR under normal conditions 14 Tissue Perfusion SVR is influenced by: Blood viscosity determined (mainly) by the percentage of erythrocytes (hematocrit) decreases in anemia; increases in polycythemia or dehydration 15 Tissue Perfusion SVR is influenced by: Blood vessel elasticity elastic blood vessels expand and recoil to maintain a constant pressure gradient in the vasculature reduced elasticity reduces the ability for arteries to absorb some pressure during heart contraction Expansion Recoil 16 Blood Volume Typically, total blood volume stays relatively constant. However, distribution of blood volume can change, which affects venous return and SVR 17 Perfusion = Systemic Vascular Blood Cardiac Output Resistance Pressure (CO) (SVR) (BP) 18 Blood Pressure The force of blood flow against the blood vessels (mmHg). 19 Blood Pressure Ppulse 21 Blood Pressure Mean Arterial Pressure (MAP): the average pressure in the arteries during one cardiac cycle. normal range: 70-100 mmHg P mean = ⅓ P systolic + ⅔ P diastolic Why does diastolic pressure accounts for ⅔ of MAP? Pulse Pressure (PP): the difference between systolic and diastolic pressures. normal value: