The document covers the anatomy and physiology of the human heart, detailing its chambers, valves, and blood vessels while explaining blood flow using color codes. It discusses the heart's electrical conduction system, regulation of heart rate, and various cardiac conditions, such as angina and myocardial infarction. The document also touches on concepts like cardiac output, heart murmurs, and the impact of various factors on heart health.

1.  Draw the human heart and the main blood
vessels in/out of the heart.
 Label the following on your diagram:
 4 chambers
 4 valves
 All blood vessels going into/out of heart
 Using a blue pencil, indicate oxygen-poor blood
flow
 Using a red pencil, indicate oxygen-rich blood
flow

3.  Cardiac muscle cells can contract spontaneously and
independently
 Regulation of heart activity:
1. Autonomic nervous system
▪ Epinephrine, thyroxine: ↑ heart rate
▪ Low Ca2+
levels: ↓ heart rate
1. Intrinsic conduction system
▪ Built into heart tissue & sets basic rhythm
▪ Pacemaker = Sinoatrial (SA) NodeSinoatrial (SA) Node

4. Sequence of action:
1. Sinoatrial (SA) node – right atrium
▪ Generates impulses  Starts each heartbeat
1. Atrioventricular (AV) node – between atria &
ventricles
▪ Atria contract
1. Bundle of His (or AV bundle)
2. Bundle branches – interventricular septum
3. Purkinje fibers – spread within ventricle walls
▪ Ventricles contract

7.  Records the electrical activity of the heart
 Electrocardiograph: graphic record of heart activity

8.  P wave: atria contact
 QRS complex: ventricles
contract
 T wave: ventricles relax

12.  Cardiac cycleCardiac cycle = events of one heartbeat
 SystoleSystole: contraction of ventricles
 DiastoleDiastole: relaxation of ventricles
 Cardiac Output Animation

13.  ““Lub”:Lub”: closing of AV
valves
 ““Dub”:Dub”: semilunar
valves close at end of
systole

14.  Angina pectoris: heart muscle
deprived of O2,crushing chest
pain
 Myocardial infarction (Heart
Attack): prolonged angina,
heart cells may die

15.  Ischemia: Lack of adequate blood supply to heart
 Fibrillation: uncoordinated shuddering of heart
muscle, useless pump
 Major cause of death from heart attacks

16.  Damage to SA node  slower heart rate
 Install artificial pacemaker
 Damage to AV node  Heart block: ventricles beat
at own rate (slower or not at all)
 Tachycardia: rapid heart rate (>100 beats/min)
 Bradycardia: very slow heart rate (<60 beats/min)
 Heart murmur: abnormal or unusual heart sounds
 Often valve problems

17.  Cardiac Output (CO) = Heart Rate (HR) x Stroke Volume
(SV)
 Stroke volume: volume of blood pumped out by
one ventricle with each best
Average adult:
CO = HR (75 beats/min) x SV (70 ml/beat)
CO = 5250 ml/min

18.  Progressive weakening of heart
 Low heart efficiency  circulation inadequate to
meet tissue needs
 Caused by:
 Coronary atherosclerosis – clogged coronary
vessels
 Persistent high blood pressure
 Multiple heart attacks – scar tissue