A+P II CH 12 HW
Which ion triggers synaptic vesicles to discharge neurotransmitter into the synaptic cleft?
calcium
Damage to ependymal cells would most likely affect the
formation of cerebrospinal fluid.
In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by
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?
glutamate
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.
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.
The minimum stimulus required to trigger an action potential is known as the
threshold
Small, wandering cells that engulf cell debris and pathogens in the CNS are called
microglia
________ 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.
Deteriorating changes in the distal segment of an axon as a result of a break between it and the soma is called ________ degeneration.
Wallerian
The ________ division of the peripheral nervous system brings sensory information to the central nervous system.
afferent
IPSPs (inhibitory postsynaptic potentials)
are local hyperpolarizations.
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.
Most neurons lack ________ and so are permanently blocked from undergoing cell division.
centrioles
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
A shift of the resting transmembrane potential toward 0 mV is called
depolarization
Opening of sodium channels in the axon membrane causes
depolarization
The ________ division of the nervous system carries motor commands to muscles and glands.
efferent
EPSPs (excitatory postsynaptic potentials) occur when
extra sodium ions enter a cell.
Which type of ion channel is always open?
leak
The presence of ________ dramatically increases the speed at which an action potential moves along an axon.
myelin
Which of these neurotransmitters does NOT bind to a plasma membrane receptor?
nitric oxide
The tiny gaps between adjacent Schwann cells are called
nodes of Ranvier.
The myelin sheath that covers many CNS axons is formed by
oligodendrocytes.
Rapid impulse conduction from "node" to "node" is called
saltatory propagation.
Which neurotransmitter has widespread effects on a person's attention and emotional state?
serotonin
Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated
spatial summation.
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
A neuron that receives neurotransmitter from another neuron is called
the postsynaptic neuron.
