Which organ can tolerate poor perfusion for up to two hours?

• A. Brain
• B. Skeletal muscle
• C. Heart
• D. Kidneys

Answer: (B)

Organs vary in how long they can go without adequate blood flow because of differences in metabolic demand and energy needs. Skeletal muscle has a relatively lower resting metabolic rate and can survive longer on limited oxygen delivery, often tolerating poor perfusion for extended periods. In contrast, the brain requires a constant, high level of oxygen and glucose to keep neurons functioning, so lack of perfusion leads to rapid cell death within minutes. The heart also depends on continuous blood flow to supply its continuous contractions; without it, myocardial cells quickly fail. The kidneys rely on steady perfusion to filter blood and maintain function, and damage can occur relatively quickly when perfusion is reduced. Because skeletal muscle can endure hypoperfusion longer than these other organs, it is the best answer for tolerating poor perfusion for up to about two hours.