CARDIAC MUSCLES AND CONDUCTIVE SYSTEM

1. CARDIAC MUSCLESAND CONDUCTIVE SYSTEM 1.ATRIAL MUSCLE 2.VENTRICULAR MUSCL 3.CONDUCTIVE FIBERS A.SA NODE B.AV NODE C.INTERNODAL FIBERS D.AV FIBERS (BUNDLE OF HIS) E.LEFT AND RIGHT BUNDLE BRANCH F.PURKIINJE FIBERS

2. Interatrial pathway Atrioventricular (AV) node Sinoatrial (SA) node Right atrium Left atrium Internodal pathway Left branch of bundle of His Right branch of bundle of His Left ventricle Right ventricle Purkinje fibers Fig. 9-7, p. 247

3. Histology of cardiac muscle

5. Pacemaker activity of cardiac autorhythmic cells

6. Direction of ventricular excitation

7. ACTION POTENTIAL OF DIFFERENT PARTS OF THE HEART • 1.PACE MAKER OF THE HEART SANODE • 2.ATRIAL ACTION POTENTIAL • 3.ACTION POTENTIAL OF THE VENTRICLES • 4.DELAY IN THE AV NODE • 5.HIGH VELOCITY IN THE PURKINJE FIBERS • 6.REFRACTORY PERIOD • A.ABSOLUTE • B.RELATIVE

10. PHASE Mechanical Response 0 = Rapid Depolarization (inward Na+ current) 1 1 = Overshoot 2 0 2 = Plateau (inward Ca++ current) 3 = Repolarization (outward K+ current) 0 MEMBRANE POTENTIAL (mV) 4 = Resting Potential 3 4 -90 TIME

11. ACTION POTENTIALS VENTRICULULAR CELL SAN 1 2 0 0 0 3 0 3 4 -50 -50 MEMBRANE POTENTIAL (mV) 4 -100 -100

13. CONTROL OF EXITATION AND CONDUCTION 1-SYMPATHETIC 2-PARASYMPATHETIC 3-IONS