Human Anatomy Chapter 12

Which of the following is not a characteristic of neurons? A) longevity B) inability to divide C) high metabolic rate D) ability to survive without oxygen

ability to survive without oxygen

The white matter is the site where neuron cell bodies are clustered.

FALSE

The supporting cells of the nervous system that surround and wrap neurons are derived from embryonic neuroepithelial cells from the ectoderm.

TRUE

In an axodendritic synapse, the region of the postsynaptic neuron that binds the released neurotransmitter is the ________.

dendrite

These regions of a neuron are characterized by numerous, short cytoplasmic extensions and are often referred to as receiving regions.

dendrite

These regions of the neuron direct electrical currents toward the cell body. A) synapse B) axon terminal C) axon D) cell body E) dendrite

dendrite

These glial cells arise from embryonic white blood cells. A) ependymal cells B) microglia C) oligodendrocytes D) satellite cells

microglia

Which cells are the macrophages of the CNS? A) ependymal cells B) microglial cells C) satellite cells D) Schwann cells

microglial cells

A somatic motor neuron carries A) information that signals muscle contraction in the organs in the ventral cavity. B) information, such as pain, from the viscera in the ventral cavity to the CNS. C) motor commands to the skeletal musculature. D) information from the skin to the CNS.

motor commands to the skeletal musculature.

Some small neurons in the CNS have no axon, only dendrites, and are A) multipolar. B) bipolar. C) unipolar. D) pseudounipolar.

multipolar.

The majority of neurons in the body are A) multipolar. B) bipolar. C) unipolar. D) pseudounipolar.

multipolar.

White matter represents A) aggregations of neuron cell bodies in the brain. B) aggregations of neuron cell bodies in the spinal cord. C) myelinated axons traveling together in the CNS. D) dendrites traveling together in the ANS.

myelinated axons traveling together in the CNS.

Sensory neurons arise primarily from the A) neural crest. B) alar plate. C) basal plate. D) neural tube.

neural crest.

A nerve cell is the same as a A) nerve. B) nerve fiber. C) neurilemmocyte. D) neuron.

neuron.

The chemical substance that is released at axon terminals is called a A) hormone. B) neurotransmitter. C) synaptic vesicle. D) Nissl body.

neurotransmitter.

Which cells provide the myelin sheath for neurons in the CNS? A) Schwann cells B) astrocytes C) microglial cells D) oligodendrocyctes

oligodendrocyctes

Interneurons are found A) only in the visceral nervous system. B) only in the CNS. C) only in the PNS. D) only in the autonomic nervous system.

only in the CNS.

Which of the following is not considered a special somatic sense? A) smell B) taste C) pain D) equilibrium

pain

The covering of a fascicle within a nerve is the A) endoneurium. B) perineurium. C) ectoneurium. D) epineurium.

perineurium.

Neurofibrils A) form synapses with axons of postsynaptic neurons. B) help circulate cerebrospinal fluid. C) prevent the neuron from being pulled apart when subjected to tensile forces. D) receive incoming stimuli and pass the signal toward the cell body.

prevent the neuron from being pulled apart when subjected to tensile forces.

Which of the following is the correct arrangement of a reflex arc? A) receptor, sensory neuron, integration center, motor neuron, effector B) integration center, receptor, sensory neuron, motor neuron, effector C) effector, sensory neuron, integration center, motor neuron, receptor D) receptor, motor neuron, integration center, effector, sensory neuron

receptor, sensory neuron, integration center, motor neuron, effector

These glial cells surround the cell bodies of sensory neurons within ganglia of the PNS. A) astrocytes B) microglia C) satellite cells D) Schwann cells

satellite cells

A monosynaptic reflex arc is an example of A) a converging circuit. B) parallel processing. C) a reverberating circuit. D) serial processing.

serial processing.

A man walking barefoot stepped on a piece of glass. His foot jerked upward in which type of reflex?

somatic, polysynaptic withdrawal reflex

Axodendritic synapses occur between letter "E" on the diagram and this region on a proximal neuron.

A

Identify the letter that indicates the region of a neuron with a name that means "little hill."

B

Identify which letter represents the most abundant category of glial cells in the CNS.

B

Identify the letter that indicates a Schwann cell.

C

Identify which diagram represents a microglial cell.

C

Identify the letter that indicates the gaps between Schwann cells that are known as myelin sheath gaps (nodes of Ranvier).

D

Identify which diagram represents cells that produce and circulate cerebrospinal fluid.

D

Identify the letter that indicates the region of a neuron where neurotransmitters are released.

E

Identify which diagram represents a cell that produces a myelin sheath in the central nervous system.

E

Identify which letter represents an oligodendrocyte.

E

The somatic motor subdivision of the peripheral nervous system is considered to be an involuntary nervous system.

FALSE

A neuron is a collection of nerve fibers in the PNS.

FALSE

All of the neuron's organelles are localized to the cell body.

FALSE

Less than 15% of all neurons are interneurons.

FALSE

Microglia are ciliated to help circulate cerebrospinal fluid (CSF).

FALSE

Oligodendrocytes and Schwann cells myelinate neurons within the peripheral nervous system.

FALSE

Which of the following statements about an axon is false? A) It is also referred to as a nerve fiber. B) It has branches. C) It carries nerve impulses toward the cell body. D) It has a uniform diameter.

It carries nerve impulses toward the cell body.

Which cells provide the myelin sheath for neurons in the PNS? A) astrocytes B) microglial cells C) Schwann cells D) oligodendrocytes

Schwann cells

The difference between myelinated and unmyelinated axons is that A) Schwann cells are not associated with unmyelinated axons. B) Schwann cells form more widely spaced nodes of Ranvier in unmyelinated axons. C) Schwann cells simultaneously surround multiple axons in myelinated axons. D) Schwann cells wrap around myelinated axons in concentric layers.

Schwann cells wrap around myelinated axons in concentric layers.

Any long axon is called a nerve fiber.

TRUE

Chromatophilic bodies are clusters of rough ER and free ribosomes that produce the large amount of proteins needed by a neuron.

TRUE

General visceral sensory impulses include pain, temperature, nausea, and hunger.

TRUE

Gliomas are tumors of glial cells. This type of cancer is difficult to treat, and the one-year survival rate is poor.

TRUE

Microglia are derived from blood stem cells rather than from neural tube and crest cells.

TRUE

Most neurons in the body are multipolar neurons.

TRUE

Special somatic senses have receptors that are located mostly in the head, including hearing and balance and vision.

TRUE

Which of the following statements about neurotransmitters is false? A) They alter the permeability of the postsynaptic cell membrane. B) They are waves of positive charges that travel down axons. C) They are released from synaptic vesicles. D) They diffuse across the synaptic cleft.

They are waves of positive charges that travel down axons.

Which of the following statements concerning sensory neurons is incorrect? A) Most are pseudounipolar. B) Most have their cell bodies in ganglia outside the CNS. C) They have peripheral and central processes. D) They contain only dendrites.

They contain only dendrites.

Of the following, which is the only structure that is in the PNS, as opposed to the CNS? A) a tract B) white matter C) a ganglion D) gray matter

a ganglion

An axon collateral from one neuron that circles back and synapses with a previous neuron describes A) a converging circuit. B) parallel processing. C) a reverberating circuit. D) serial processing.

a reverberating circuit.

All of the following are characteristics of dendrites except that they A) are more extensive branching than axons. B) always conduct action potentials. C) conduct signals toward the cell body. D) typically occur as more than one per cell.

always conduct action potentials.

In this part of a neuron, neurofilaments, actin microfilaments, and microtubules are particularly abundant, providing structural support and a transport network. A) synapse B) axon terminal C) axon D) cell body E) dendrite

axon

This neuronal region transmits electrical impulses away from the cell body. A) synapse B) axon terminal C) axon D) cell body E) dendrite

axon

This part of the neuron may have branching collaterals. A) synapse B) axon terminal C) axon D) cell body E) dendrite

axon

This tends to be the longest cytoplasmic projection froma neuron. A) synapse B) axon terminal C) axon D) cell body E) dendrite

axon

Action potentials travel along the A) axon membrane. B) dendrite membrane. C) cell body. D) myelin.

axon membrane.

Which of the following is the correct path an impulse takes across a synapse? A) axon of postsynaptic neuron, dendrite of presynaptic neuron, synaptic cleft B) dendrite of presynaptic neuron, synaptic cleft, axon of postsynaptic neuron C) axon of presynaptic neuron, synaptic cleft, dendrite of postsynaptic neuron D) synaptic cleft, dendrite of postsynaptic neuron, axon of presynaptic neuron

axon of presynaptic neuron, synaptic cleft, dendrite of postsynaptic neuron

Mitochondria are particularly abundant here. A) synapse B) axon terminal C) axon D) cell body E) dendrite

axon terminal

The ________ of a presynaptic neuron associates with the dendrite of a postsynaptic neuron. A) synapse B) axon terminal C) axon D) cell body E) dendrite

axon terminal

These regions of a neuron are also referred to as terminal boutons. A) synapse B) axon terminal C) axon D) cell body E) dendrite

axon terminal

Vesicles containing neurotransmitters are located in A) a synaptic cleft. B) axon terminals. C) the postsynaptic region of dendrites. D) the nodes of Ranvier.

axon terminals.

Motor neurons arise primarily from the A) alar plate. B) basal plate. C) ependyma. D) neural crest.

basal plate.

Which relatively rare type of neuron has two processes extending from opposite sides of the cell body? A) bipolar B) multipolar C) pseudounipolar D) unipolar

bipolar

An axosomatic synapse occurs between the axon terminals of one neuron and the ________ of a proximal neuron. A) synapse B) axon terminal C) axon D) cell body E) dendrite

cell body

This region of a neuron contains chromatophilic substance or Nissl bodies. A) synapse B) axon terminal C) axon D) cell body E) dendrite

cell body

This region of the neuron contains a single nucleus surrounded by cytoplasm. A) synapse B) axon terminal C) axon D) cell body E) dendrite

cell body

Most synapses transmit communicating signals using A) chemical signaling molecules-neurotransmitters. B) electrical impulses travelling through gap junctions. C) physical contact between adjacent neurons. D) chemical signaling molecules released from neuroglia.

chemical signaling molecules-neurotransmitters.

Nonmyelinated axons A) are thicker than myelinated axons. B) are not associated with any Schwann cells. C) conduct impulses more slowly than myelinated axons. D) occur in the PNS, but not in the CNS.

conduct impulses more slowly than myelinated axons.

During embryo development, neurons that make "bad" connections A) are inhibited by chemicals released from astrocytes. B) are turned off by inhibitory synapses in reverberating circuits. C) develop collaterals that seek out appropriate target cells. D) die by apoptosis.

die by apoptosis.

Which of the following most immediately encases the smallest component of a nerve? A) endoneurium B) epineurium C) fascicle D) perineurium

endoneurium

Ciliated neuroglial cells that form an epithelium and play an active role in forming and moving cerebrospinal fluid are A) ependymal cells. B) Schwann cells. C) oligodendrocytes. D) astrocytes.

ependymal cells.

The entire nerve is surrounded by a tough fibrous sheath called the A) endoneurium. B) perineurium. C) ectoneurium. D) epineurium.

epineurium.

Gray matter in the CNS contains all of the following except A) neuron cell bodies. B) neuroglia. C) dendrites. D) fiber tracts.

fiber tracts.

Regeneration of peripheral axons requires A) construction of a collateral that branches from the point of damage. B) deposition of neurofilaments to bridge the gap between the original axon fragments. C) formation of a tube by Schwann cells to guide growth. D) migration of neural stem cells from the hippocampus.

formation of a tube by Schwann cells to guide growth.

The peripheral nerve fibers that measure the degree of stretch in the biceps brachii muscle and its tendons are classified as A) general somatic sensory. B) general somatic motor. C) special visceral sensory. D) general visceral motor.

general somatic sensory.

The peripheral nerve fibers that speed up the movement of the digestive tract are classified as A) general visceral sensory (afferent). B) special visceral sensory. C) general visceral motor (efferent). D) special somatic motor.

general visceral motor (efferent).

Most tumors in the brain originate from A) glial cells. B) multipolar neurons. C) bipolar neurons. D) unipolar neurons.

glial cells.

Ganglia represent A) groups of axons. B) groups of dendrites. C) groups of neuron cell bodies. D) groups of synapses.

groups of neuron cell bodies.

A node of Ranvier (myelin sheath gap) A) occurs only in ganglia. B) is one segment of the myelin sheath. C) occurs in the PNS but not in the CNS. D) is a bare region of axonal membrane in myelinated axons only.

is a bare region of axonal membrane in myelinated axons only.

Myelin on axons functions to A) make the axons live longer. B) store nutrients (fat) for use by the neurons. C) cover nodes of Ranvier. D) speed the rate of impulse conduction and insulate neighboring axons from one another.

speed the rate of impulse conduction and insulate neighboring axons from one another.

Chemical signals diffuse between neurons at this location. A) synapse B) axon terminal C) axon D) cell body E) dendrite

synapse

This is the site of communication between neurons. A) synapse B) axon terminal C) axon D) cell body E) dendrite

synapse

In the region of the spinal cord, the cell bodies of most interneurons lie in A) sensory ganglia. B) the PNS. C) the dorsal half of the gray matter. D) the ventral half of the white matter.

the dorsal half of the gray matter.

The complexity of the CNS can be attributed to A) the large number of sensory neurons carrying information to the CNS. B) the different types of receptors outside the CNS. C) the large number of interneurons in the CNS. D) the large number of motor neurons leaving the CNS.

the large number of interneurons in the CNS.

An example of proprioception is A) the contraction of the triceps brachii. B) the contraction of pharyngeal arch muscles used in chewing. C) sensing a feather touch the skin. D) the sensation you feel during a wake-up stretch.

the sensation you feel during a wake-up stretch.

The type of axon that conducts impulses most slowly is A) thick, myelinated. B) thick, unmyelinated. C) thin, myelinated. D) thin, unmyelinated.

thin, unmyelinated.