NERVOUS SYSTEM: TRUE OR FALSE? Humans only use 10% of their brain or less False! The brain uses 20% of the energy we consume each day True! Mental abilities are separated into discrete left and right “halves” False! New neurons cannot be created False! The brain makes up 2% of our body weight True! The brain does not change after growth that occurs during adolescence False! A nerve is a single cell False! The brain uses 50% of the oxygen we breathe in False! The longest cells in the human body are in the sciatic nerve True! The human brain is firm and grey False!