Question
Rate of heart beat is determined by
Purkinje Fibres
Papillary muscles
SA-node
AV-node
Solution
C.
SA-node
The contraction of heart depends on small cluster of specialised muscle cells which are embedded in the upper wall of the right atrium. This cluster of cells is called the sino-atrial node (SA-node). It automatically and rhythmically sends out impulses that initiate each heart beat.
