A&P 2 Chapter 12 HW

The myelin sheath that covers many CNS axons is formed by

Oligodendrocytes

The ________ division of the peripheral nervous system brings sensory information to the central nervous system.

afferent

IPSPs (inhibitory postsynaptic potentials)

are local hyperpolarizations

The simplest level of information processing takes place at the

axon hillock

The site in the neuron where EPSPs and IPSPs are integrated is the

axon hillock

Part complete At a(n) ________ synapse, a neurotransmitter is released to stimulate the postsynaptic membrane.

chemical

In order to communicate with multiple cells at the same time, an axon may branch along its length, producing side branches called

collaterals

The ________ division of the nervous system carries motor commands to muscles and glands.

efferent

Part complete In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by

forming a cellular cord that directs axonal regrowth.

Part complete Which of these neurotransmitters does NOT bind to a plasma membrane receptor?

nitric oxide

Which neurotransmitter has widespread effects on a person's attention and emotional state?

serotonin

The tiny gaps between adjacent Schwann cells are called

nodes of Ranvier

Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated

spatial summation

Part complete A neuron that receives neurotransmitter from another neuron is called

the postsynaptic neuron

The minimum stimulus required to trigger an action potential is known as the

threshold

________ account for roughly half of the volume of the nervous system.

Neuroglia

When you take a pain reliever, which of the following best describes, in general terms, how this affects the threshold of neurons?

Taking a pain reliever increases the threshold

Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons?

The axon would be unable to generate action potentials

Part complete How does blocking retrograde axoplasmic transport in an axon affect the activity of a neuron?

The soma becomes unable to respond to changes in the distal end of the axon.

Part complete Deteriorating changes in the distal segment of an axon as a result of a break between it and the soma is called ________ degeneration.

Wallerian

Part complete When a person has a stroke, blood leaks into the brain tissue. Which type of neuroglia cells would make structural repairs to the damage?

astrocytes

The largest and most numerous of the glial cells in the central nervous system are the

astrocytes

Which ion triggers synaptic vesicles to discharge neurotransmitter into the synaptic cleft?

calcium

Most neurons lack ________ and so are permanently blocked from undergoing cell division.

centrioles

A shift of the resting transmembrane potential toward 0 mV is called

depolarization

Opening of sodium channels in the axon membrane causes

depolarization

EPSPs (excitatory postsynaptic potentials) occur when

extra sodium ions enter a cell

Damage to ependymal cells would most likely affect the

formation of cerebrospinal fluid

Part complete Which of the following is the most important excitatory neurotransmitter in the brain that is important in learning and memory?

glutamate

Which type of ion channel is always open?

leak

Part complete Small, wandering cells that engulf cell debris and pathogens in the CNS are called

microglia

The presence of ________ dramatically increases the speed at which an action potential moves along an axon.

myelin

Rapid impulse conduction from "node" to "node" is called

saltatory propagation

Part complete The site of intercellular communication between a neuron and another cell is the

synapse

Axons terminate in a series of fine extensions known as

telodendria