The period of time during which a second action potential cannot be initiated, no matter how large the applied stimulus is the absolute refractory period. Which statement is true for this period?

1. Potassium channels are open and the membrane is hyperpolarized
2. It immediately follows the relative refractory period
3. It allows an action potential to proceed in two directions along the length of an axon
4. It occurs when the sodium channels are open

The blood–brain barrier (BBB) separates the circulating blood from the brain and extracellular fluid in the central nervous system (CNS) and:

1. Functions to control the exchange of substances between blood and the extracellular fluid in the CNS

2. Is comprised of the cells that line the largest blood vessels in the brain

3. Is comprised of the cells that line the ventricles of the brain

4. Prevents diffusion of lipid soluble molecules from the blood to the brain

In the peripheral nervous system, the cells that are capable of forming a regeneration tube through which a severed peripheral axon can regrow are the:

1. Schwann cells
2. astrocytes
3. oligodendrocytes
4. microglia

A local anesthetic is a medication that causes reversible absence of pain sensation. They:
1. block the closure of voltage regulated potassium ion channels
2. stimulate the opening of voltage regulated potassium ion channels
3. block the opening of the voltage regulated sodium ion channels
4. stimulate the opening of voltage regulated sodium ion channels

What would be true for the nociceptors?

1. Nociceptors respond to extreme stimuli

2. All nociceptors are located in the skin

3. Nociceptors are involved in noise perception

4. Nociceptor pathways of conduction cannot be inhibited

A diffuse network of nerve pathways in the brainstem connecting the spinal cord, cerebrum, and cerebellum, and mediating the overall level of consciousness is the:

1. Hippocampus
2. Hypothalamus
3. Reticular activating system
4. Limbic system

Motor aphasia may result due to the lesion of:

1. Broca's area
2. Wernicke's area
3. the cingulate gyrus
4. the angular gyrus

When a person enters a dark room, in the rods of his eyes:

1. cGMP levels are high.
2. cGMP levels are low.
3. G protein is degraded.
4. An influx of Ca²⁺ ions is prevented.

As a sound grows in intensity while remaining at one frequency the basilar membrane:

1. vibrates more toward the base.
2. vibrates more toward the apex.
3. does not vibrate at all.
4. vibrates equally all along its length.

A drug acts as an inhibitor of acetylcholinesterase. Administration of this drug would lead to:
1. accumulation of acetylcholine in the synaptic cleft
2. accumulation of acetylcholinesterase in the synaptic cleft
3. muscle relaxation
4. repeated action potentials