S

Conduction and

ContractionIn the Human Heart

Purpose of the Heart

S Pump Blood

S Enable Oxygen and Nutrient Delivery

S Force Blood Into the Lungs

S Force Blood Through the Body

Cardiac Anatomy

S Four Total Chambers

1. Smaller Atria on Top

2. Larger Ventricles on Bottom

S Valves Prevent Backflow

S Nodes That Regulate Contractile Signals

S Nerves That Carry Contractile Signals

Cardiac Conduction

S Impulse Created in Sinoatrial Node

S Travels Through Atria Towards Ventricles

S Causes Contraction as it Travels

S Passes Through Atrioventricular Node

S Travels Along Nerves Through the Ventricles

Coordinated Contraction

S Gap Junctions Between Cells in a Chamber

S Provides a Means For Rapid Signal Transmission

S Special Nerves in Ventricles Known as Purkinje Fibers

S Carry Contractile Signals Faster Than Any Other Nerve

S All Cells in a Chamber Contract Together

Coordination

S Ensures That the Atria Contract Before the Ventricles

S Moves Blood in the Proper Direction

S Allows For Maximum Contractile Effort

S Increases Stroke Volume

S Delivers More Oxygen and Nutrients

Effects of Damage

S Improper Conduction

S Inefficient Contraction

S Decreased Oxygen and Nutrient Delivery

S Fatigue

S Death

Evaluation

S Electrocardiogram

S Echocardiogram

S Stress Tests

S Holter Monitoring

S Performed by EKG Technician

References

S http://www.ekgtechniciansalary.org/