Average cardiac output is

Which valve is located between the right atrium and the right ventricle?

In a rabbit,the opening of the post caval vein into the right auricle is guarded by:

What is the 'Bundle of $HIS$' a group of?

$SA$ node (Sinoatrial node) ke baare mein sahi kathan chuniye:
$I$. Located at the right upper corner of the right atrium.
$II$. Heart of heart.
$III$. It initiates the rhythmic contractile activity of the heart.
$IV$. It is called the pace-keeper of the heart.
$V$. It is called the pacemaker of the heart.
Which of the following options contains the correct statements?

Which valve is located between the left atrium and the left ventricle?