Brain Glucose Substrate — FRCA Primary MCQ

Instant feedback + full explanation. One question, done properly.

ModeratePhysiology - Endocrine & MetabolicBrain Glucose SubstrateFRCA Primary

In the fasted state the brain's primary energy substrate is:

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Glucose

Under normal conditions the brain relies almost exclusively on glucose. Fatty acids cannot effectively cross the BBB. During prolonged starvation (>3 days) ketone bodies can provide up to 60-70% of brain energy requirements.

Reference: Power Kam 2018 Principles of Physiology for the Anaesthetist