Which of the following substances may diffuse through the lipid bilayer of the plasma membranes of brain capillaries and enter the brain?
A) nicotine
B) caffeine
C) alcohol
D) barbiturates
E) all of these

Question

Quizplus · Accepted Answer

All of these substances (nicotine, caffeine, alcohol, and barbiturates) are small, nonpolar molecules that can diffuse through the lipid bilayer of the plasma membranes and enter the brain.

Which of the Following Substances May Diffuse Through the Lipid