Chapter 12 Homework

The tiny gaps between adjacent Schwann cells are called Vesicles Axolemma Terminals Neurillema Nodes of Ranvier

Nodes of Ranvier

The ________ division of the peripheral nervous system brings sensory information to the central nervous system. parasympathetic autonomic somatic peripheral afferent

afferent

The simplest level of information processing takes place at the __________. soma axon hillock dendrites axon terminals

axon hillock

The site in the neuron where EPSPs and IPSPs are integrated is the dendritic membrane axon hillock electrical synapse chemical synapse synaptic terminal

axon hillock

At a(n) ________ synapse, a neurotransmitter is released to stimulate the postsynaptic membrane. cell osmotic electrical gap chemical

chemical

In order to communicate with multiple cells at the same time, an axon may branch along its length, producing side branches called __________. axon terminal collaterals initial segment telodendria

collaterals

The ________ division of the nervous system carries motor commands to muscles and glands. peripheral autonomic spinal afferent efferent

efferent

Which neurotransmitter has widespread effects on a person's attention and emotional state? dopamine norepinephrine serotonin GABA endorphins

serotonin

Which of these neurotransmitters does NOT bind to a plasma membrane receptor? serotonin nitric oxide norepinephrine GABA

nitric oxide

The myelin sheath that covers many CNS axons is formed by satellite cells astrocytes microglia ependymal cells oligodendrocytes

oligodendrocytes

A neuron that receives neurotransmitter from another neuron is called a satellite cell the postsynaptic neuron an oligodendrocyte the motor neuron the presynaptic neuron

the postsynaptic neuron

The minimum stimulus required to trigger an action potential is known as the summation all-or-none response potential incentive threshold

threshold

________ account for roughly half of the volume of the nervous system. Efferent fibers Neuroglia Dendrites Synapses Axons

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 affects the all-or-none principle of neurons - So, neurons reaching threshold send an action potential at 50% - Taking a pain reliever does not affect the threshold of neurons - Taking a pain reliever decreases the threshold - Taking a pain reliever increases the threshold

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 absolute refractory period would be shorter than normal - Neurons would depolarize more rapidly - Action potentials would lack a repolarization phase - The axon would be unable to generate action potentials - None, because the chemically gated sodium channels would still function

The axon would be unable to generate action potentials

How does blocking retrograde axoplasmic transport in an axon affect the activity of a neuron? - The neuron becomes unable to produce action potentials - The soma becomes unable to respond to changes in the distal end of the axon - The neuron becomes unable to depolarize when stimulated - The neuron becomes unable to produce neurotransmitters - The soma becomes unable to export products to the synaptic terminals

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

Deteriorating changes in the distal segment of an axon as a result of a break between it and the soma is called ________ degeneration. neural Wallerian conduction central peripheral

Wallerian

IPSPs (inhibitory postsynaptic potentials) - are local hyperpolarizations - are local depolarizations - block the efflux of calcium ions - increase membrane permeability to sodium ions - block the efflux of potassium ions

are local hyperpolarizations

The largest and most numerous of the glial cells in the central nervous system are the microglia oligodendrocytes astrocytes satellite cells ependymal cells

astrocytes

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 satellite cells oligodendrocytes ependymal cells

astrocytes

Which ion triggers synaptic vesicles to discharge neurotransmitter into the synaptic cleft? potassium calcium sodium magnesium

calcium

Most neurons lack ________ and so are permanently blocked from undergoing cell division. cytoplasm endoplasmic reticula a nucleus ribosomes centrioles

centrioles

A shift of the resting transmembrane potential toward 0 mV is called repolarization depolarization hyperpolarization polarization potential difference

depolarization

Opening of sodium channels in the axon membrane causes repolarization hyperpolarization increased negative charge inside the membrane inhibition depolarization

depolarization

EPSPs (excitatory postsynaptic potentials) occur when - more calcium ions than usual leak out of a cell - extra sodium ions enter a cell - chloride ions enter a cell - more potassium ions than usual leak out of a cell - hyperpolarizations occur

extra sodium ions enter a cell

Damage to ependymal cells would most likely affect the formation of cerebrospinal fluid formation of ganglia repair of axons transport of neurotransmitters within axons formation of myelin sheaths

formation of cerebrospinal fluid

In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by - clearing away cellular debris - regenerating cell bodies for the neurons - producing new axons - producing more satellite cells that fuse to form new axons - forming a cellular cord that directs axonal regrowth

forming a cellular cord that directs axonal regrowth

Which of the following is the most important excitatory neurotransmitter in the brain that is important in learning and memory? serotonin noradrenaline glycine glutamate gamma aminobutyric acid

glutamate

Which type of ion channel is always open? voltage-gated leak mechanically-gated chemically-gated

leak

Small, wandering cells that engulf cell debris and pathogens in the CNS are called ependymal cells satellite cells astrocytes oligodendrocytes microglia

microglia

The presence of ________ dramatically increases the speed at which an action potential moves along an axon. plasma protein myelin neurilemma a capsule glial cells

myelin

Rapid impulse conduction from "node" to "node" is called synaptic transmission divergent propagation saltatory propagation continuous propagation spatial propagation

saltatory propagation

Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated inhibition of the impulse temporal summation hyperpolarization spatial summation impulse transmission

spatial summation

The site of intercellular communication between a neuron and another cell is the synapse telodendria hillock collateral axolemma

synapse

Axons terminate in a series of fine extensions known as collaterals terminals synapses dendrites telodendria

telodendria