Anatomy & Physiology Chapter 12 The Nervous System Cells

Front 1

List the major subdivisions of the human nervous system

Back 1

Central and peripheral.

Front 2

What two organs make up the central nervous system?

Back 2

Brain and spinal cord

Front 3

What are the five main types of glia?

Back 3

Astrocytes, microglia, ependymal cells, oligondendrocytes, and Schwann cells

Front 4

Describe the myelin sheath found on some nerve fibers

Back 4

The myelin sheath is formed by layers of Schwann cell membrane containing the white, fatty substance called myelin. It is important in the proper conduction of impulses along the nerve fiber

Front 5

What is a neurilemma?

Back 5

The neurilemma is a nerve sheath formed as each Schwann cell wraps around the nerve fiber, and its nucleus and cytoplasm are squeezed to the perimeter

Front 6

List the characteristics of life in humans

Back 6

Autopoiesis—organisms are self-organizing or self-maintaining and nonliving structures are not.

Front 7

Define the term metabolism as it applies to the characteristics of life

Back 7

Metabolism is the sum of all physical and chemical reactions in the body. Each characteristic of life is related to these reactions.

Front 8

What are the three layers of connective tissues that hold the fibers of a nerve together?

Back 8

Endoneurium, perineurium, and epineurium

Front 9

What is the difference between a nerve and a tract?

Back 9

Nerves are bundles of peripheral nerve fibers held together by several layers of connective tissues. Bundles of nerve fibers are called tracts.

Front 10

How does white matter differ from gray matter?

Back 10

White matter is made up of myelinated fibers. Cell bodies and unmyelinated fibers make up the gray matter

Front 11

Under what circumstances can a nerve fiber be repaired?

Back 11

Nerve fibers can sometimes be repaired if damage is not extensive, when the cell body and neurilemma remain intact and scarring has not occurred.

Front 12

In a resting neuron, what positive ion is most abundant outside the plasma membrane? What positive ion is most abundant inside the plasma membrane?

Back 12

Sodium is more abundant outside, while potassium is more abundant inside

Front 13

What is meant by the term threshold potential?

Back 13

18. The threshold potential occurs when the magnitude of the local depolarization surpasses a limit (typically -59 mV).

Front 14

How does impulse conduction in an unmyelinated fiber differ from impulse conduction in a myelinated fiber?

Back 14

Myelinated fibers conduct impulses faster than unmyelinated fibers

Front 15

What are the three structural components of a synapse?

Back 15

Synaptic knob, synaptic cleft, and the plasma membrane of the postsynaptic neuron.

Front 16

What is an EPSP? What is an IPSP?

Back 16

EPSP: excitatory postsynaptic potential. IPSP: inhibitory postsynaptic potential

Front 17

How do excitatory neurotransmitters differ from inhibitory neurotransmitters?

Back 17

Excitatory neurotransmitters have an excitatory effect at synapses. Inhibitory neurotransmitters have an inhibitory effect at the synapses

Front 18

What are the four chemical classes of neurotransmitters?

Back 18

Acetycholine, amines, amino acids, and other small molecules

Front 19

What are neuromodulators?

Back 19

A neuromodulator is a “cotransmitter” that regulates or modulates the effects of the neurotransmitter(s) released along with it

Front 20

Action Potential

Back 20

nerve impulse; membrane potential of an active neuron

Front 21

Axon

Back 21

in a neuron, the single process that extends from the axon hillock and transmits impulses away from the cell body

Front 22

Central Nervous System

Back 22

brain and spinal cord

Front 23

Dendrite

Back 23

in a neuron, the single process that extends from the axon hillock and transmits impulses away from the cell body

Front 24

Gila

Back 24

nonexcitable supporting cells of nervous tissue; formerly called neuroglia

Front 25

Membrane Potential

Back 25

difference in electrical charge between inside and outside of the plasma membrane

Front 26

Myelin

Back 26

lipoprotein substance in the myelin sheath around many nerve fibers that contributes to high-speed conductivity of impulse

Front 27

Nerve

Back 27

bundle nerve fibers, plus surrounding connective tissue, located outside the brain or spinal cord

Front 28

Neuron

Back 28

nerve cell, including its processes (axons and dendrites)

Front 29

Neuromodulator

Back 29

“cotransmitter” that regulates the effects of neurotransmitter(s) released along with it

Front 30

Peripheral Nervous System (PNS)

Back 30

consists of the nerve tissues that lie in the periphery, or “outer regions,” of the nervous system.

Front 31

Reflex Arc

Back 31

automatic involuntary reaction to a stimulus resulting from a nerve impulse passing over a reflex arc

Front 32

Synapse

Back 32

membrane-to-membrane junction between a neuron and another neuron, effector cell, or sensory cell; function to propagate action potential (via neurotransmitters)

Front 33

Anatomy & Physiology Chapter 12 Nervous System Cells

Back 33

Anatomy & Physiology Chapter 12 Nervous System Cells