All arteries carry oxygenated blood, except:

In birds and mammals,the oxygenated blood is received by ...$A$... and deoxygenated blood is received by ...$B$.... The ventricles pump it out without any mixing of oxygenated and deoxygenated blood. Choose the correct option for $A$ and $B$.

Bicuspid and tricuspid valves open when:

What is meant by cardiac output?

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

Pericardial fluid is present between . . . . . . of heart.