Label the structures in the following diagram of a neuron.

a. ___

b. ___

c. ___

d. ___

e. ___

f. ___

g. ___

h. ___

i. ___

Regulation by the nervous system provides:

(a) Relatively slow, but long-lasting, responses to stimuli

(b) Swift, long-lasting responses to stimuli

(c) Swift, but brief, responses to stimuli

(d) Relatively slow, short-lived responses to stimuli

In the CNS, a neuron typically receives information from other neurons at its:

(a) Axon

(b) Nissl bodies

(c) Dendrites

(d) Nucleus

Phagocytic cells in nervous tissue of the CNS are:

(a) Astrocytes

(b) Ependymal cells

(c) Oligodendrocytes

(d) Microglia.

The neural cells responsible for the analysis of sensory inputs and coordination of motor outputs are:

(a) Neuroglia

(b) Interneurons

(c) Sensory neurons

(d) Motor neurons

Depolarization of a neuron plasma membrane will shift the membrane potential toward:

(a) 0 mV

(b) −70 mV

(c) −90 mV

(d) All of these

What factor determines the direction that ions will move through an open membrane channel?

(a) The membrane permeability to sodium ions

(b) The electrochemical gradient

(c) Intracellular negatively charged proteins

(d) Negatively charged chloride ions in the ECF

Receptors that bind acetylcholine at the postsynaptic membrane are:

(a) Chemically gated channels

(b) Voltage-gated channels

(c) Passive channels

(d) Mechanically gated channels

What are the major components of the peripheral nervous system?

What are the major components of

(a) the central nervous system?

What are the major components of

(c) the enteric nervous system?

Which two types of neuroglia insulate neuron cell bodies and axons in the PNS from their surroundings?

What three functional groups of neurons are found in the nervous system? What is the function of each type of neuron?

If the resting membrane potential of a neuron is −70 mV and the threshold is −55 mV, a membrane potential of −60 mV will:

(a) Produce an action potential

(b) Make it easier to produce an action potential

(c) Make it harder to produce an action potential

(d) Hyperpolarize the membrane

Why can't most neurons in the CNS be replaced when they are lost to injury or disease?

What is the difference between anterograde flow and retrograde flow?

What is the functional difference among chemically gated (ligand-gated), voltage-gated, and mechanically gated ion channels?

State the all-or-none principle of action potentials.

Describe the steps involved in the generation of an action potential.

What is meant by saltatory propagation? How does it differ from continuous propagation?

What are the structural and functional differences among type A, B, and C fibers?

Describe the events that occur during nerve impulse transmission at a typical cholinergic synapse.

What is the difference between temporal summation and spatial summation?

Harry has a kidney condition that causes changes in his body's electrolyte levels (concentration of ions in the extracellular fluid). As a result, he is exhibiting tachycardia, an abnormally fast heart rate. Which ion is involved, and how does a change in its concentration cause Harry's symptoms?

Twenty neurons synapse with a single receptor neuron. Fifteen of the 20 neurons release neurotransmitters that produce EPSPs at the postsynaptic membrane, and the other 5 release neurotransmitters that produce IPSPs. Each time one of the neurons is stimulated, it releases enough neurotransmitter to produce a 2-mV change in potential at the postsynaptic membrane. If the threshold of the postsynaptic neuron is 10 mV, how many of the excitatory neurons must be stimulated to produce an action potential in the receptor neuron if all 5 inhibitory neurons are stimulated? (Assume that spatial summation occurs.)

In multiple sclerosis, there is intermittent and progressive damage to the myelin sheath of peripheral nerves. This results in poor motor control of the affected area. Why does destruction of the myelin sheath affect motor control?

What factor determines the maximum frequency of action potentials that could be propagated by an axon?