Question

Consider that the human brain weighs about 1 kg and contains 10^11 cells. Assuming that each cell is entirely filled with water, and knowing that 1 cm^3 of water weighs 1 g, calculate the volume of a brain cell (in picoliters).

Answer 1

Since 1 kg = 1,000 g and 1 g = 1 cm^3, the brain is approximately 1,000 cm^3. Placing this number of the number of cells gives 10^-8 cm^3 per cell. Then convert to mL knowing that 1 cm^3 = 1 mL. Lastly, convert from mL to picoliters (10^12 pL = 10^3 mL) to obtain 10 pL.