1. CARDIOVASCULAR SYSTEM Heart Physiology

2. CARDIAC CYCLE Systole *Atria Contract, Ventricles Fill *Ventricles Contract, Blood Forced into Aorta and Pulmonary Trunk Diastole *Atria Relax & Fill *Ventricles Passively Receive Blood from the Atria

4. BLOOD PRESSURE BP = pressure blood exerts on inner blood vessel walls BP keeps blood moving between heart contractions BP rises & falls in response to heart contraction & relaxation

5. BLOOD PRESSURE Systole -Contraction of ventricles causes arterial pressure to rise -Systolic pressure (SBP) is the maximum pressure during contraction

6. BLOOD PRESSURE CONTINUED Diastole -Relaxation and refilling of ventricles while semilunar valves are closed -Arterial pressure drops as blood flows “downstream” -Diastolic pressure (DBP) is the minimum pressure just before the next systole

8. Average BP = 120/80 Arterial surge in pressure = Pulse Pulse rate usually = heart rate Average adult pulse = 60-80 BPM

9. CONDUCTION SYSTEM OF THE HEART Specialized Cardiac Muscle Tissue Capable of Generating & Conducting Action Potentials Autorhythmic Stimulates Contraction of Myocardial Tissue

10. CONDUCTION SYSTEM OF THE HEART continued 5 Components: -Sinoatrial Node (Pacemaker) *Right Atrium *Spontaneously Depolarize *Activates Atrial Contraction *Origin of Heart Beat *Action Potential Spreads to:

11. CONDUCTION SYSTEM OF THE HEART continued -Atrioventricular (AV) Node *Rt. atrium (interatrial septum) *Action potential spreads to: -Atrioventricular Bundle (Bundle of His) *Only electrical pathway between atria & ventricles (C.T.Block) *Interventricular septum *Carries action potential through interventricular septum to:

12. CONDUCTION SYSTEM OF THE HEART continued -Bundle Branches (Left & Right ) *Interventricular septum *Carries action potential toward respective ventricles -Purkinje Fibers *Myocardium of Ventricles *Conduct action potentials to ventricular myocardium

14. ELECTROCARDIOGRAM (ECG/EKG) Record of Electrical Changes in Heart Muscle Electrical Changes due to Depolarization & Repolarization of Cardiac Muscle Fibers Metal Electrodes Applied to Skin, Attached to Physiograph, Pick-up Electrical Activity Normal Cardiac Cycle Gives Rise to Characteristic “Waves”

15. ELECTROCARIDOGRAM (ECG/EKG) continued P Wave -SA Node Stimulates Atrial Depolarization -Occurs Prior to Atrial Contraction QRS Complex -Ventricular Depolarization -More Tissue, More Electrical Activity, Larger Wave -Occurs Prior to Ventricular Contraction T Wave -Ventricular Repolarization

17. EKG ABNORMALITIES Tachycardia (BPM>100) Bradycardia (BPM<60) Premature Beats (Ectopic Source) Flutter (BPM 250-350) Fibrillation (Rapid, Uncoordinated)

18. HEART SOUNDS Caused by Closing of Heart Valves AV Valves -prevent blood from flowing backwards into atria -“Lubb” Semilunar Valves -prevent blood from flowing backwards into ventricles -“Dupp”

19. HEART MURMURS Abnormal sound Often indicates valve disorder Causes: -Congenital defects -Scarring -Insufficiency/Backflow