Ch 12 - Nervous Tissue

Motor innervation to the stomach is classified as ________

visceral motor

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

False

Less than 15% of all neurons are interneurons. True False

False

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

False

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

False

How are gray matter and white matter arranged in the CNS? White matter is deep to gray matter in the brain, except in the region of the cerebral cortex, where there is an extra superficial layer of white matter. Gray matter and white matter are intermingled in both the brain and spinal cord, depending on whether the axons are myelinated or unmyelinated. White matter surrounds the central cavity of the spinal cord and gray matter surrounds this white matter. Gray matter is deep to the superficial white matter in the spinal cord.

Gray matter is deep to the superficial white matter in the spinal cord.

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

motor commands to the skeletal musculature.

The majority of neurons in the body are bipolar. unipolar. multipolar. pseudounipolar.

multipolar.

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

myelinated axons traveling together in the CNS.

This neuronal region transmits electrical impulses away from the cell body. synapse axon terminal axon cell body dendrite

axon

Action potentials travel along the cell body. dendrite membrane. axon membrane. myelin.

axon membrane.

Gray matter in the CNS contains all of the following except fiber tracts. neuroglia. dendrites. neuron cell bodies.

fiber tracts.

The chemical substance that is released at axon terminals is called a neurotransmitter. hormone. synaptic vesicle. Nissl body.

neurotransmitter.

Interneurons are found only in the visceral nervous system. only in the PNS. only in the autonomic nervous system. only in the CNS.

only in the CNS.

In what instance is axonal regeneration possible? If the cell body of a PNS neuron survives when an axon is damaged, axon filaments can extend peripherally from the injured site toward the original target. In the CNS, neuroglia form parallel bands to guide axonal extensions to allow reconnection to the original target. If the cell body of a PNS neuron dies, but the axon remains intact, the axon can regenerate a new neuronal cell body. Axon filaments extend through a regeneration tube formed by oligodendrocytes.

If the cell body of a PNS neuron survives when an axon is damaged, axon filaments can extend peripherally from the injured site toward the original target.

Which of the following statements describes interneurons? Interneurons are an embryonic cell type that becomes a neuron. Interneurons are multipolar neurons that are confined to the CNS and are linked together in chains that form complex neuronal pathways. Interneurons are neurons only found in the autonomic nervous system. Interneurons are unipolar neurons whose cell bodies are located in the dorsal root ganglia.

Interneurons are multipolar neurons that are confined to the CNS and are linked together in chains that form complex neuronal pathways.

Which statement is true concerning neuronal regeneration? In the CNS, if neuroglial cells form parallel bands to guide new axonal extensions, some return of function to the damaged region of the brain or spinal cord is possible. According to recent studies, regions of the thalamus and medulla oblongata have been shown to form new neurons. After injury, most neurons are prompted to undergo mitosis. Reinnervation of the target organ with partial recovery of function is sometimes possible in the PNS. None of the listed choices is correct.

Reinnervation of the target organ with partial recovery of function is sometimes possible in the PNS.

Which structure is responsible for formation of the regeneration tube following injury to an axon? endoneurium myelin droplets Schwann cells neurofilaments

The Schwann cells that surrounded the damaged axon form a regeneration tube and direct the route of the regrowing axon.

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

They contain only dendrites

Most neurons in the body are multipolar neurons. True False

True

Of the following, which is the only structure that is found in the PNS, as opposed to in the CNS? a ganglion a tract white matter gray matter

a ganglion

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

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

The ________ of a presynaptic neuron associates with the dendrite of a postsynaptic neuron. synapse axon terminal axon cell body dendrite

axon terminal

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

bipolar

This region of the neuron contains a single nucleus surrounded by cytoplasm. synapse axon terminal axon cell body dendrite

cell body

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

ependymal cells.

Motor neurons __________. form junctions with effector cells, stimulating muscles to contract or glands to secrete originate as bipolar neurons whose processes divide during development are located exclusively in the CNS have their cell bodies located in the dorsal half of the gray matter in the spinal cord have their cell bodies located in ganglia in the PNS

form junctions with effector cells, stimulating muscles to contract or glands to secrete

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

formation of a tube by Schwann cells to guide growth.

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

general visceral motor (efferent).

Ganglia represent groups of synapses. groups of dendrites. groups of axons. groups of neuron cell bodies.

groups of neuron cell bodies.

The somatic sensory division of the PNS __________. includes sensation of nausea and hunger stimulates contraction of skeletal muscles includes motor innervation of smooth muscle, cardiac muscle, and glands includes general senses of pressure, pain, vibration, and temperature in body wall and limbs

includes general senses of pressure, pain, vibration, and temperature in body wall and limbs SubmitMy AnswersGive Up

Which part or parts of the neuron are found in the white matter of the central nervous system? cell bodies and dendrites all parts of the neuron: dendrites, cell bodies, axonal process long axonal processes central processes of unipolar neurons

long axonal processes The white matter of the CNS is composed of long myelinated and nonmyelinated axons. All neuronal cell bodies are located in gray matter in the CNS.

The visceral motor division of the PNS __________. regulates the contraction of smooth and cardiac muscle and regulates secretion by the body's many glands regulates only the parasympathetic division of the ANS regulates only the sympathetic division of the autonomic nervous system includes taste and smell

regulates the contraction of smooth and cardiac muscle and regulates secretion by the body's many glands

What is the function of synaptic vesicles inside axon terminals? increase the speed of nerve transmission store and release neurotransmitters storage of Nissl (chromatophilic) bodies generation of nerve impulses conduction of nerve impulses

store and release neurotransmitters

Chemical signals diffuse between neurons at this location. synapse axon terminal axon cell body dendrite

synapse

This is the site of communication between neurons. synapse axon terminal axon cell body dendrite

synapse

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

the dorsal half of the gray matter.