The pericardium and the pericardial fluid help in
Protecting the heart from friction, shocks and keeps it moist
Pumping the blood
Receiving the blood from various parts of the body
None of the above
Valves are necessary in veins but not in arteries because
Describe external structure of heart.
The coronary sinus in the heart is situated along its
Draw a labelled diagram showing internal structure of heart.
What is the function of nodal muscular tissue ?