The outer membrane of a neuron is semipermeable. This means that
A) only sodium ions can cross the membrane.
B) the fluid outside the membrane is positively charged.
C) it allows some substances to pass through the membrane.
D) the membrane must be depolarized before any particles can pass through it.

Question

Quizplus · Accepted Answer

The semipermeability of the outer membrane of a neuron implies that some substances can pass through the membrane, while others cannot. This process is selective and dependent on the size and charge of the particles. For example, small molecules, such as oxygen and carbon dioxide, can diffuse across the membrane, while larger molecules require specialized transport mechanisms. Therefore, option C is the correct answer. Option A is incorrect because it is not accurate that only sodium ions can cross the membrane. Option B is false because the charge of fluid outside the membrane is dependent on the specific environment and is not always positively charged. Option D is incorrect because not all particles require depolarization for passage.

The Outer Membrane of a Neuron Is Semipermeable