Chapter 13 Questions

Unipolar neurons cannot produce action potentials because they have no axon

False. Unipolar neurons have an axon and produce action potentials

In the peripheral nervous system, the sonar of the neurons are concentrated in enlarged, knotlike structures called___connected to the nerves.

Ganglia

The soma of a mature neuron lacks...

centrioles

Neurons arise from embryonic...

ectoderm

A friend takes a flash photography of you, and you continue to see an image of the flash unit for several seconds afterwards. The phenomenon is the result of ___circuit.

reverberating

Which of the following appears earlier than all the rest in prenatal development of the nervous system?

the neural plate

Neurotransmitters are found in ...

the presynaptic terminal

Nerves that control the mobility of the stomach or rate of the heartbeat would belong to ...

the visceral motor division

Neurons that convey information to the CNS are called sensory or ___, neurons.

Afferent

Prenatal degeneration of the forebrain results in a birth defect called ___.

Anencephaly

A/An___synapse is firmed when a presynaptic neuron synapses with the cell body of a postsynaptic neuron.

Axosomatic

Neurons receiving incoming signals by way of specialized processes called___.

Dendrites

Inter neurons connect sense organs to the CNS

False. Sensory (afferent) neurons connect sense organs to the CNS.

The myelin sheath covers the neurilemma of a nerve fiber

False. The myelin sheath is deep to the neurilemma.

Interneurons occur in the brain and spinal cord of the CNS and in ganglia of the PNS

False. Interneurons are contained entirely within the CNS.

Nodes of Ranvier are present only in myelinated fibers of PNS

False. Nodes of Ranvier also exist in the PNS

The integrative functions of the nervous system are performed mainly by...

Interneurons

Another name for the axon of a neuron is ...

Nerve fiber

The___and___are necessary for regeneration of damaged nerve fibers in the peripheral nervous system.

Neurilemma, endoneurium

In the central nervous system, cells called ___perform one of the same functions that Schwann cells do in the peripheral nervous system except the brain and spinal cord is called the___.

Oligodendrocytes

All of the nervous system except the brain and spinal cord is called the ___

Peripheral nervous system

At a given synapse, the ___ neuron has the neurotransmitter receptors.

Postsynaptic

Motor effects that depend on repetitive output from a neural pool are most likely to use the ___ type of neural circuit.

Reverbating

Adult neurons are incapable of mitosis

True

Dendrites never contain synaptic vessels

True

Most neurons have dendrites than axons

True

Nerve signals travel faster in myelinated nerve fibers than in unmyelinated ones

True

There are more glial cells than neurons in the nervous system

True

The glial cells that guide migrating neurons in the developing fetal brain are ...

astrocytes

The glial cells that destroy microorganisms in the CNS are...

microglia