<span>The mitral valve does this between the left atrium and ventricle. The "lub" is the sound of the tricuspid and mitral valves closing. Each of your heart's ventricles has an outlet valve. The right ventricle uses the pulmonary valve to help move blood into the pulmonary arteries.</span>
after giving 30 chest compressions (at a rate of 100 per minute), follow up by checking if the child is breathing.
Colic is always a possible cause, however it is pretty normal for babies to experience crying as stomach pain is inevitable. It could also be the formula milk the baby is drinking, trying lactose free formula may be a solution.