Nervous System

Question 1

specialized cells capable of transmitting electrical impulses and then translating them into electrical signals; use electrical and chemical forms of communication

Answer 1

neurons

Question 2

occurs via ion exchange and the generation of membrane potentials down the length of the axon

Answer 2

electrical communication

Question 3

occurs via neurotransmitter release from the presynaptic cell and their binding to the postsynaptic cell

Answer 3

chemical communication

Question 4

part of neuron:

the cell body, location of nucleus and organelles such as endoplasmic reticulum and ribosomes

Answer 4

soma

Question 5

part of neuron:

appendages emanating from soma, receive signals from other cells

Answer 5

dendrites

Question 6

part of neuron:

where cell body transitions to axon, where action potentials are initiated

Answer 6

axon hillock

Question 7

transmission of electrical impulses down axon

Answer 7

action potential

Question 8

part of neuron:

long appendage down which action potential travels

Answer 8

axon

Question 9

part of neuron:

end of axon from which neurotransmitters are released

Answer 9

nerve terminal/synaptic bouton

Question 10

part of neuron:

exposed areas of myelinated axons that permit saltatory conduction

Answer 10

nodes of Ranvier

Question 11

part of neuron:
consists of nerve terminal of presynaptic neuron, the membrane of the postsynaptic cell, and microscopic space between the two (synaptic cleft)

Answer 11

synapse

Question 12

coats many axons, insulating substance that prevents signal loss; prevents dissipation of neural impulse and crossing of neural impulses from adjacent neurons

Answer 12

myelin

Question 13

creates myelin in CNS

Answer 13

oligodendrocytes

Question 14

creates myelin in PNS

Answer 14

Schwann cells

Question 15

bundle of myelinated axons in PNS; may carry multiple types of information: sensory, motor, or both

Answer 15

nerve

Question 16

group of cell bodies (of neurons within a nerve) in PNS

Answer 16

ganglia

Question 17

bundle of myelinated axons in CNS; only carry one type of information

Answer 17

tracts

Question 18

group of cell bodies (of neurons within a tract) in CNS

Answer 18

nuclei

Question 19

other cells within the nervous system in addition to neurons

Answer 19

neuroglia/glial cells

Question 20

neuroglia:
nourish neurons and form the blood-brain barrier, which controls the transmission of solutes from the bloodstream into nervous tissue

Answer 20

astrocytes

Question 21

neuroglia:
line the ventricles of the brain and produce cerebrospinal fluid, which physically supports the brain and serves as a shock absorber

Answer 21

ependymal cells

Question 22

neuroglia:

phagocytic cells that ingest and break down waste products and pathogens in the CNS

Answer 22

microglia

Question 23

net electric potential difference that exists across the cell membrane, created by movement of charged particles across membrane; for neurons: about -70 mV

Answer 23

resting membrane potential

Question 24

selective permeability of ____ and ____ ions is used to maintain resting potential

Answer 24

Na+ and K+

Question 25

pumps ___ sodium ions out of cell for every ___ potassium ions pumped in, helps maintain resting potential

Answer 25

Na+/K+ ATPase (3, 2)

Question 26

cause depolarization of neuron

Answer 26

excitatory signals

Question 27

cause hyperpolarization of neuron

Answer 27

inhibitory signals

Question 28

refers to integration of multiple signals near each other in time

Answer 28

temporal summation

Question 29

refers to addition of multiple signals near each other in space

Answer 29

spatial summation

Question 30

used to propagate signals down the axon

Answer 30

action potential

Question 31

caused when enough excitatory stimulation occurs and the cell is brought to the threshold voltage and the voltage-gated sodium channels open

Answer 31

depolarized

Question 32

strong force of neuron that causes sodium to flow into it; continues depolarizing neuron

Answer 32

electrochemical gradient

Question 33

about +35 mV, when sodium channels are inactivated and potassium channels open

Answer 33

peak of action potential

Question 34

caused when potassium channel opens, potassium flows out of neuron due to strong electrochemical gradient

Answer 34

repolarized

Question 35

occurs when potassium channels stay open long enough to over-shoot resting potential, then potassium channel closes

Answer 35

hyperpolarizes

Question 36

brings neuron back to resting potential and restores sodium and potassium gradients

Answer 36

Na+/K+ ATPase

Question 37

Period when axon is hyperpolarized

Answer 37

refractory period

Question 38

refractory period when cell is unable to fire another action potential

Answer 38

absolute refractory period

Question 39

refractory period when cell requires a larger than normal stimulus to fire an action potential

Answer 39

relative refractory period

Question 40

propagates down the length of the axons because the influx of sodium in one segment of axon brings the subsequent segment of the axon to threshold

Answer 40

impulse

Question 41

where neurotransmitters are released into synapse

Answer 41

nerve terminal

Question 42

opens when action potential arrives at nerve terminal

Answer 42

voltage-gated calcium channels

Question 43

causes fusion of vesicles filled with neurotransmitters with the presynaptic membrane, resulting in exocytosis of neurotransmitters into synaptic cleft

Answer 43

influx of calcium

Question 44

bind to receptors on post synaptic cell, may be ligand-gated ion channels or G-protein coupled receptors

Answer 44

neurotransmitters

Question 45

three ways neurotransmitter is cleared from postsynaptic receptor to stop propagation of signal:

Answer 45

1) neurotransmitter can enzymatically by broken down 2) neurotransmitter can be absorbed back into presynaptic cell by uptake channels 3) neurotransmitter can diffuse out of synaptic cleft

Question 46

can absorb neurotransmitters back into presynaptic cell

Answer 46

uptake channels

Question 47

consists of myelinated axons in CNS

Answer 47

white matter

Question 48

consists of unmyelinated cell bodies and dendrites in CNS

Answer 48

grey matter

Question 49

where white matter is deeper than grey matter

Answer 49

brain

Question 50

where grey matter is deeper than white matter

Answer 50

spinal cord

Question 51

use the ability of interneurons in spinal cord to relay information to the source of a stimulus while simultaneously routing it to the brain

Answer 51

reflex arcs

Question 52

the sensory (afferent, presynaptic) neuron fires directly onto the motor (efferent, postsynaptic) neuron

Answer 52

monosynaptic reflex arc

Question 53

the sensory neuron may fire onto a motor (efferent) neuron as well as interneurons that fire onto other motor (efferent) neurons

Answer 53

polysynaptic reflex arc