Final answer:
During CPR, chest compressions do not circulate the same amount of blood as the heart does normally, but aim to sustain life until medical help can arrive or the heart resumes beating.
Step-by-step explanation:
The question is whether CPR chest compressions circulate the same amount of blood as the heart does normally. The answer is b. No. CPR involves manually applying pressure to the sternum between the lines at T4 and T9 to compress the heart to maintain blood flow to crucial organs such as the brain. However, even with proper technique, the manual compressions provided during CPR do not match the complete efficacy of a normally beating heart. The depth and rate of compressions are aimed at sustaining life by circulating enough blood to prevent irreversible brain damage, but this is not as efficient as the natural cardiac output.