All arteries carry oxygenated blood, except:

$A$: Endocardium provides a smooth lining for the inside of the heart and covers the valves of the heart.
$R$: Endocardium is continuous with the endothelial lining of the large blood vessels associated with the heart and the rest of the cardiovascular system.

Where are the $Purkinje$ fibers found?

If the tricuspid valve of a human heart is partially non-functional due to an injury to the chordae tendineae,which of the following will be immediately affected?

Which of the following carries oxygenated blood?

Draw a diagram of the human heart and label the $SAN$,$AVN$,$AV$ bundle,bundle of His,and Purkinje fibres.