The 'sodium-potassium pump' pumps ___________.

Correct Answer: A

Rationale: The sodium-potassium pump is a membrane protein that actively transports sodium ions out of the neuron and potassium ions into the neuron. This process requires energy in the form of ATP and helps maintain the resting membrane potential. By creating a concentration gradient of these ions, the pump ensures that the neuron is ready to generate action potentials and transmit nerve impulses efficiently.

Correct Answer: C

Rationale: The brain and spinal cord are protected by three layers of meninges: the dura mater, arachnoid mater, and pia mater. These layers provide structural support, cushioning, and protection against physical injury. The dura mater is the outermost layer, the arachnoid mater is the middle layer, and the pia mater is the innermost layer. Therefore, three is the correct answer as it accurately describes the number of meningeal layers.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.