Final answer:
The standard incision to open the chest is a median sternotomy, which allows access to the heart and lungs for various surgeries. In emergencies, CPR, which involves compressions on the sternum, is used to sustain blood flow until medical help arrives or the heart resumes beating.
Step-by-step explanation:
The standard incision to open the chest in surgical procedures is typically a median sternotomy, which involves cutting through the sternum (breastbone). This provides access to the heart and lungs for operations such as heart transplants, bypass surgeries, or valve repairs. In emergencies related to cardiac arrest, cardiopulmonary resuscitation (CPR) can be a lifesaving technique. The location of the heart in the thorax allows individuals to perform CPR by applying pressure on the sternum, with the aim of manually compressing the blood within the heart to maintain blood flow, especially to the brain where cells are highly sensitive to oxygen deprivation. CPR is performed until spontaneous heart activity resumes or the patient is declared deceased by a healthcare professional.