Fill in the blanks :

(i) Ventricles have …………… walls when compared with those of auricles.

(ii) Ventricles give rise to two large blood vessels called …………… and ……………

Where are the following located?

(i) Tricuspid valve

(ii) Mitral valve

(iii) Pulmonary semilunar valves

Name the following :

(i) Contraction phase of heart.

(ii) The structure that holds the heart valves in position.

Mention the phase of heart beat in which both the atrio-ventricular valves are closed.