CHAPTER 12

The slowest category of nerve fibers are the?

C fibers, and they conduct impulses at 1 meter per second.

The connective tissue wrapping that surrounds bundles (fascicles) of axon is the

Perineurium

Chemically gated ion channels are mainly found in the ______________ segment of a neuron?

Receptive

The glial cell that protects neuron cell bodies located within angle is the?

Satellite

A mixed nerve is one that contains both?

Sensory and motor neurons

In a mixed nerve

Some axons transmit sensory information and others transmit motor information

As an axon approaches the cell onto which it will terminate, it generally branches repeatedly into several

Telodendria

When transmission occurs at a synapse, neurotransmitter is released by?

The presynaptic neuron's synaptic knob in the synaptic cleft

What do all glial cells have in common?

They assist neurons in their respective functions

The type of voltage-gated channel that possesses an inactiviation gate that temporarily closes after the channel is active is the

Voltage-gated sodium channel

Which occurs first

absolute refractory period

The endoneurium is composed of

areolar connective tissue

The glial cell with the responsibility of occupying the space left by dead or dying neurons is the

astrocyte

With damage to nerve fibers, larger distances between the site of damage and the target structure innervated result in

decreased

According to Ohm's law current is

directly related to voltage and inversely related to resistance

In neurophysiology, the term "summation" refers to the addition of

postsynaptic potentials at the initial segment.

Following damage to axons nearby, oligondendrocytes

secrete growth-inhibitory molecules

The afferent division of the nervous system is also known as the _____________ division

sensory

Which function is not a function of the motor division of the nervous system

transmits impulses from the viscera

Continuous conduction of a nerve impulse occurs only along

unmylinated axons

Somatic motor neuron axons fall into the category of

A fibers

When a nerve impulse reaches the transmissive segment of a neuron?

Calcium diffuses into the neuron and neurotransmitter is released by exocytosis.

The type of neuronal circuit that ensures that we continue to breathe while asleep is _________________ circuit?

Converging

Which choice correctly orders the connective tire wrappings of a nerve, beginning at the outermost layer?

Endineurium-perineurium-epineurium

The Glial cell that myelinates and insulates axon in the peripheral nervous system is the?

Ependymal cell

Neural stem cells in the CNS

Have no known function.

Which is not characteristic of neurons?

High mitotic rate

Which statement is consistent with the current understanding of the neural tissue

Most neurons formed in fetal development last a lifetime, but some brain regions in adults can generate new neurons

Based on structure, the most common type of neuron is the ________________ neuron

Multipolar

Which functional class of neurons lies entirely within the cns?

interneurons