Exam 13: A: Nervous System Cells

Action potentials usually occur in the axon of the cell.

Multiple sclerosis is the most common primary disease of the CNS.

Action potentials travel in only one direction along a nerve fiber.

Many anesthetics produce their effects by inhibiting the opening of the potassium channels,blocking the repolarization of nerve impulses.

The peripheral nervous system includes both efferent and afferent nerves.

Spatial summation is the effect produced by a rapid succession of stimuli on a single postsynaptic neuron.

When a neuropeptide is secreted with one or two other neurotransmitters,it is thought to serve as a neuromodulator,regulating the effects of the other neurotransmitters.

The magnitude of the action potential peaks when the sodium channels close.

When "central" and "peripheral" are used as directional terms in the nervous system,a nerve fiber may be called peripheral if it extends from the cell body toward the central nervous system.

There are more glia cells in the brain than there are neurons.

Only axons are covered in myelin.

An inhibitory postsynaptic potential is produced through the hyperpolarization of the postsynaptic membrane.

Nerve fibers with many Schwann cells forming a thick myelin sheath are called myelinated fibers,or gray fibers.

Interneurons are found only in the central nervous system.

Serotonin and histamine are both in the monoamine subclass of neurotransmitters.

Schwann cells and oligodendrocytes share a common function,but in different parts of the nervous system.

The cell will send an impulse during the relative refractory period as long as the stimulus is below threshold.

The difference in electrical charge between the inside and outside of a membrane is called the membrane potential.

Dendrites carry impulses toward the cell body.

The nervous system contains two types of cells,neurons and glia cells,but only neurons conduct nerve impulses.