Cardiovascular Physiology 1 Cardiovascular physiology Presented by Mansour

Cardiovascular Physiology 1

Cardiovascular physiology Presented by Mansour Esmaili Assistant Professor of physiology 3

References Textbook of Medical Physiology Review of Medical Physiology, 2010. Ganong Principles of Physiology 2010. Berne and Levy 2011. Guyton Main 4

Session 1 Introduction and Cardiac Electrical Activity Berne and levy Chapter 16 (p 292 -302) Guyton Chapter 9 (p 101 -103) 5

Introduction to physiology 6

Introduction to physiology Low pressure System (10 mm. Hg) High pressure system (100 mm. Hg) Lymphatic Circulation is associated with both ones 7

Electrical activity of heart 8

Electrical activity of heart Physiologic Anatomy of Cardiac Muscle 9

Electrical activity of heart Heart is composed of two syncytiums: • Atrial syncytium • Ventricular syncytium 10

Electrical activity of heart Membrane potentials caused by ion diffusion Na Ca -90 mv Cl Electrical Gradient Chemical Gradient K 11

Electrical activity of heart Nernst Equation Electrical Force Chemical Force Ion Extracellular Concentrations (m. M) Intracellular Concentrations (m. M) Equilibrium Potential (m. V) Na 145 10 +61 K 4 135 -94 Ca 2 0. 0001 +132 Cl 110 5 -70 12

Electrical activity of heart 13

Electrical activity of heart Refractory periods 14

Electrical activity of heart In 1855, Kolliker and Muller reported that when they placed the nerve of an innervated skeletal muscle in contact with the surface of a beating frog's heart, the skeletal muscle twitched with each cardiac contraction. 15

Electrical activity of heart Fast Response K Na Ca K K K 16

Electrical activity of heart Diltiazem, a Ca++channel antagonist 17

Electrical activity of heart Slow Response Ca K 18

Electrical activity of heart Fast response to slow response Myocardial ischemia Cardiac arrest 19

Electrical activity of heart Mechanical Activity No tetanus 20

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