automatic

pulsated

myogenic

Purkinje fibers

Sinoatrial node

Atrioventricular node

Bundle of His

Right atrium

Right ventricle

Left atrium

Left ventricle

Narrow lumen

Absence of valve

Thick muscular wall

SA node $\rightarrow$ Purkinje fibers $\rightarrow$ AV node $\rightarrow$ Bundle of His

Bundle of His $\rightarrow$ Purkinje fibers $\rightarrow$ AV node $\rightarrow$ SA node

SA node $\rightarrow$ AV node $\rightarrow$ Bundle of His $\rightarrow$ Purkinje fibers

lub - AV valves closed

dub - AV valves closed

lub - semilunar valves closed

dub - semilunar valves closed

Electrolysis

Electromagnet

Electrocardiogram

Ensure blood flow back to the heart

Prevent blood clotting

Ensure blood flow in one direction