In the CNS, myelin sheaths around neurons are formed by:

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

The change in membrane potential that returns it to a negative value just after an action potential has changed the membrane potential to a positive value is called as:

During the absolute refractory period along an axon membrane of a neuron, __________.
1. the potassium gates are open and K+ is diffusing down its concentration gradient
2. the sodium gates are closed and Na+ us diffusing down it concentration gradient
3. the neuron is unable to respond to a stimulus of any intensity
4. the membrane is most sensitive to stimuli

What is meant by the fact that the nerve impulses are conducted along an axon without decrement?
1. The action potentials are conducted at the same velocity.
2. The action potentials alter the threshold potential
3. The action potentials are conducted without decreasing amplitude
4. The action potentials will be produced by hyperpolariztion.

Electrical synapses differ from the chemical synapse in that they:

1. occur when two cells are joined by integrin proteins
2. are characterized by a synaptic cleft
3. occur between two cells of unequal size
4. require the presence of gap junctions

The last site in the soma where membrane potentials propagated from synaptic inputs are summated before being transmitted to the axon [often regarded as the point of initiation of action potentials] is known as:

1. postsynaptic membrane of the dendrite
2. cell body
3. axon hillock
4. axon terminal

Cocaine stimulates the synapses of specific neurons that release dopamine and other monoamines, by ______________.

1. inhibiting enzyme inactivation of dopamine or monoamines
2. blocking the dopamine or monoamine reuptake into the presynaptic axon ending
3. mimicking the effects of dopamine or monoamines on the postsynaptic cell
4. facilitating the release of dopamine or monoamines from the presynaptic terminal

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

The part of the limbic system that plays important roles in the consolidation of information from short-term memory to long-term memory is the:

The main sensory receptive area for the sense of touch is

1. the precentral gyrus
2. the postcentral gyrus
3. Wernicke's area
4. The amygdala