Structurally, the nervous system consists of which two subdivisions?
B) central and peripheral
Clusters of neuron cell bodies located outside the CNS are called
B) ganglia
Which functional division of the nervous system includes the SNS and ANS?
A) motor
In the PNS, components of the afferent division include
C) sensory neurons
Which effectors are innervated by visceral motor neurons?
A) cardiac muscle, smooth muscle, and glands
The two distinct cell types that compose all nervous tissue are
A) neurons and glial cells
In neurons, the abundant free and bound ribosomes are collectively called the
B) chromatophilic substance
The slightly expanded tips of telodendria are called
C) synaptic knobs
The cytoplasm in a neuron cell body (or sometimes the entire cell body) is called the
D) perikaryon
Structural categories of neurons include which of the following?
A) sensory, motor, and interneurons
Neurons with numerous dendrites and a single axon are structurally classified as
D) multipolar neurons
Efferent neurons transmit nerve impulses
C) from the CNS to muscles or glands
Collectively, glial cells do all of the following except
C) synthesize neurotransmitters and conduct nerve impulses
The word root glia, as in "glial cells," most nearly means
B) glue
Which pair names only neuroglia of the central nervous system?
A) ependymal cells and astrocytes
Which description refers to oligodendrocytes?
B) large, bulbous cells with slender cytoplasmic extensions
The largest and most abundant of the CNS glial cells, ____________ help form the blood-brain barrier.
D) astrocytes
Which types of glial cells are found in the peripheral nervous system?
C) neurolemmocytes and satellite cells
Which term describes the collection of lipids and proteins that may form a protective coating around an axon?
A) myelin
Myelination affects nerve impulse conduction in which of the following ways?
B) permits nerve impulses to travel continuously along the entire axon
Axon regeneration in the PNS involves ____________ in a process known as Wallerian ____________.
C) neurolemmocytes; degeneration
Nerves are bundles of parallel axons in the PNS that have three successive connective tissue wrappings, called the
D) endomysium, perimysium, and epimysium
The point at which two excitable cells contact to exchange information is called a
A) synapse
The synaptic knob of a neuron may contact another neuron anywhere except on its
B) myelin sheath
At a chemical synapse, the presynaptic membrane releases a signaling molecule called a
D) neurotransmitter
Which one of the following is not a step in the conduction of a nerve impulse across a chemical synapse?
B) calcium ions entering the synaptic cleft cause the endocytosis of synaptic vesicles
The rate of conduction of a nerve impulse is influenced by the
D) diameter of the axon and presence or absence of a myelin sheath
Which description doesnot accurately characterize neuronal pools?
A) have numerous types of circuits defined by structural features
All of the following are types of neuronal circuits except
C) proliferating
In the embryo, the neural plate (which gives rise to most nervous tissue structures) develops from
A) ectoderm
What accounts for the gray color of gray matter?
C) both of the above
Bundles of neurofilaments extending into dendrites and axons to provide structural support are called
C) neurofibrils
The phrase "terminally differentiated," as applied to mature neurons, means that they
B) cannot divide mitotically to produce daughter cells
Although they outnumber ____________ by as much as ten to one, ____________ account for only about half of the total volume of the nervous system.
A) neurons; glial cells
Their methods are different, but ____________ in the CNS and ____________ in the PNS perform similar functions.
B) oligodendrocytes; neurolemmocytes
Which glial cells behave much like certain leukocytes?
A) microglia
Although classified as glial cells, ____________ are also ____________ that line the cavities in the brain and spinal cord and help form the choroid plexus.
B) ependymal cells; epithelial cells
In the PNS, an axon may be enveloped by ____________ without being ____________.
A) neurolemmocytes; myelinated
Which glial cells participate in the repair of damaged nerves?
A) neurolemmocytes
Which nervous system divisions or components contain no afferent neurons?
A) ANS and SNS
Ironically, a ____________ neuron typically has more dendrites than a ____________ neuron.
C) unipolar; bipolar
A multipolar neuron that synapses on a gland cell is functionally classified as
A) a visceral motor neuron
In terms of nerve impulse conduction, unmyelinated is to ____________ as myelinated is to ____________.
A) continuous; saltatory
A nerve impulse involves ____________ across a neuron's plasma membrane.
C) both a and b
Axon regeneration in the CNS is restricted by which of the following factors?
D) all of the above
At a chemical synapse, ____________ are found only in the plasma membrane of the ____________ cell.
D) receptor proteins; postsynaptic
Synapses are categorized on the basis of
B) point of contact and mode of impulse transmission
Which structural classes of neurons are always sensory in function?
C) unipolar and bipolar
The ____________ is the only functional class of neuron entirely restricted to the ____________ nervous system.
D) association neuron; central
Which of the following are structural, as opposed to functional, divisions of the nervous system?(1) CNS (2) SNS (3) PNS (4) ANS
D) 1 and 3
With regard to control of effectors, ____________ is to involuntary as ____________ is tovoluntary.
B) autonomic; somatic
Sensory neurons in which of the following locations receive and transmit only visceral input?(1) skin (2) joints (3) heart (4) fascia (5) stomach
C) 3 and 5
Touch, vibration, and proprioception are examples of
A) general somatic senses
Which statement is false regarding neural circuits?
A) in parallel-after-discharge circuits, a single input leads to multiple individual outputs
Increased dietary intake of vitamin B12 and ____________ during pregnancy can dramatically reduce the incidence of neural tube defects such as ____________.
D) folic acid (folate); anencephaly and spina bifida