Source: Exemplar
What prevents backflow of blood inside the heart during contraction?
Options
Option A is correct
Valves in heart
Option B
Thick muscular walls of ventricles
Option C
Thin walls of atria
Option D
All of the remaining options
What prevents backflow of blood inside the heart during contraction?
Valves in heart
Thick muscular walls of ventricles
Thin walls of atria
All of the remaining options