Chapter 3: Cells of the Nervous System

Question 0

Glia

Answer 0

Cells in the nervous system that support the activities of neurons

Question 1

Neuron

Answer 1

A cell of the nervous system that is specialized for information processing and communication

Question 2

Synapse/Synaptic gap

Answer 2

The junction between two neurons at which information is transferred from one to another
Synaptic gap: The tiny fluid-filled space between neurons forming a synapse

Question 3

Local Circuit Neuron

Answer 3

A neuron that communicates with neurons in its immediate vicinity

Question 4

Projection Neuron

Answer 4

A neuron with a very long axon that communicates with neurons in distant areas of the nervous system

Question 5

Unipolar Neuron

Answer 5

A neuron with one branch that extends a short distance from the cell body then splits into two branches

Question 6

Multipolar Neuron

Answer 6

A neuron that has multiple branches, usually one axon and numerous dendrites

Question 7

Macroglia

Answer 7

Large glial cells, including astrocytes, oligodenrocytes, and Schwann cells

Question 8

Astrocytes

Answer 8

A large, star shaped glial cell of the central nervous system, responsible for structural support, isolation of the synapse, control of the extracellular chemical environment at the synapse, and possibly communication

Question 9

Oligodendrocytes

Answer 9

A glial cell that forms the myelin on central nervous system axons

Question 10

Schwann Cells

Answer 10

A glial cell that forms the myelin on axons in the peripheral nervous system

Question 11

Microglia

Answer 11

Tiny, mobile glial cells that migrate to areas of damage and digest debris

Question 12

Action Potential

Answer 12

Electrical Signal conducted within ONE neuron

Question 13

All-or-None Law

Answer 13

Neuron fires everything or nothing at all

Question 14

Diffusion

Answer 14

The force that moves molecules from areas of high concentration to areas of low concentration

Question 15

Concentration Gradient

Answer 15

An unequal distribution in the concentration of molecules across a cell membrane

Question 16

Threshold

Answer 16

The level of depolarization at which an action potential is initiated

Question 17

Depolarization

Answer 17

The movement of an electrical charge within a cellin a more positive direction

Question 18

Repolarization

Answer 18

The restoration of a polarized state across a membrane

Question 19

Hyperpolarization

Answer 19

The movement of the electrical charge within a cell in a more negative direction

Question 20

Refractory Period

Answer 20

Absolute: the period in which an action potential will not occur in a particular location of an axon regardless of input

Question 21

Resting Potential

Answer 21

The measurement of the electrical charge across the neural membrane when the cell is not processing information

Question 22

Salutatory Conduction

Answer 22

The movement of an action potential from node of Ranvier to node of Ranvier, down the length of a myelinated axon

Question 23

Passive Conduction

Answer 23

The movement of an action potential down the length of an unmyelinated axon

Question 24

Ionotropic Receptor

Answer 24

A receptor protein in the postsynaptic membrane in which the recognition site is located in the same structure as the ion channel

Question 25

Metabotropic Receptor

Answer 25

A protein structure embedded in the postsynaptic membrane containing a recognition site and a G protein. Neurotransmitters binding to these receptors do not directly open ion channels

Question 26

Second Messenger

Answer 26

A chemical within the postsynaptic neuron that is indirectly activated by synaptic activity and interacts with intracellular enzymes or receptors

Question 27

Reuptake

Answer 27

A process for ending the action of neurotransmitters in the synaptic gap in which the presynaptic membrane recaptures the transmitter molecules

Question 28

Enzymatic Degradation

Answer 28

Break Down of neurotransmitters by enzymes

Question 29

EPSP (Excitatory Postsynaptic Potential)

Answer 29

A small depolarization produced in the postsynaptic cell as a result of input from the presynaptic cell

Question 30

IPSP (Inhibitory Postsynaptic Potential)

Answer 30

A small hyper-polarization produced in the postsynaptic cell as a result of input from the presynaptic cell

Question 31

Neural Integration

Answer 31

The Determination of whether to fire an action potential, based on the summation of inputs to a neuron

Question 32

Spatial Summation

Answer 32

Neural integration in which the combined inputs from many synapse converge on the axon hillock, where if threshold is reached

Question 33

Temporal Summation

Answer 33

Neural intergration in which excitation from one active synapse is sufficient to initiate the formation of an action Potential

Question 34

Neuromodulation

Answer 34

Electrical Stimulation of a peripheral nerve, the spinal cord, or the brain for relief of pain; it may be done transcutaneously or with an implanted stimulator

Question 35

Axoaxonic Synapse

Answer 35

A synapse in which both the presynaptic and postsynaptic elements are axons