Final answer:
Cardiopulmonary resuscitation (CPR) is the procedure used to ventilate the lungs and circulate the blood if the patient has stopped breathing and the heart has stopped beating.
Step-by-step explanation:
The procedure to ventilate the lungs and circulate the blood if the patient has stopped breathing and the heart has stopped beating is known as cardiopulmonary resuscitation (CPR). CPR involves applying pressure on the sternum to manually compress the heart and push blood into the pulmonary and systemic circuits. The emphasis is on performing high-quality chest compressions to maintain blood flow until the patient regains spontaneous contraction or is declared dead by a healthcare professional.