Chapter 7 Pt. 2

Question 1

The neuron membrane is specialized for ____________

Answer 1

communication

Question 2

What are nerve impulses or action potentials?

Answer 2

an electrochemical signal caused by sodium ions (NA+) and potassium ions (K+) crossing the neuron’s membrane to enter and leave the cell

Question 3

What are ion channels?

Answer 3

pores in the membrane that are able to pass through without using cellular energy

Question 4

True or False: sodium channels allow the passage of ONLY sodium ions, and potassium channels allow ONLY potassium ions

Answer 4

True

Question 5

What are sodium-potassium pumps?

Answer 5

special proteins in the cell membrane that actively transport sodium and potassium ions across the membrane

Question 6

sodium-potassium pumps se cellular energy in the form of _____

Answer 6

ATP

Question 7

Each sodium-potassium pump ejects __ sodium ions form within the cell while bringing in __ potassium ions

Answer 7

3

2

Question 8

Each sodium-potassium pump ejects 3 _______ ions form within the cell while bringing in 2 _________ ions

Answer 8

sodium

potassium

Question 9

What is resting potential?

Answer 9

keeping the inside surface more negative than the outside one

Question 10

a neuron that is not transmitting an action potential is known as ______

Answer 10

resting

Question 11

What is an action potential?

Answer 11

nerve impulse; a sudden reversal in the charge difference across the membrane, followed by the restoration of the original charge difference

Question 12

What is the process of action potential?

Answer 12

1) sodium ions (Na+) enter the axon via depolarization

2) potassium (K+) ions leave the axon via repolarization

Question 13

What is the difference between depolarization and repolarization?

Answer 13

depolarization-reduction of the change difference across the membrane

repolarization- restoration of the charge difference across the membrane

Question 14

What is refractory period?

Answer 14

immediately after an action potential occurs, the neuron cannot be stimulated again for a brief instant

Question 15

_________ _______ is the reason that nerve impulses cannot reverse and go backward toward the cell body

Answer 15

refractory period

Question 16

Increasing the strength of a ________ will increase the _________ of impulses

Answer 16

stimulus

frequency

Question 17

Once initiated an action potential sweeps to the end of the _____ without diminishing in ________

Answer 17

axon

strength

Question 18

What is a neurotransmitter?

Answer 18

the chemical released from the axon’s tip

Question 19

____________ diffuse across the gap and conveys the message to the adjacent cell

Answer 19

Neurotransmitters

Question 20

What is a synapse?

Answer 20

the junction between a neuron and another cell

Question 21

What is a synaptic cleft?

Answer 21

the gap between the cells

Question 22

What is a synaptic knob?

Answer 22

a small bulblike swelling at the end of each branch

Question 23

What is the difference between a presynaptic neuron and a postsynaptic neuron?

Answer 23

presynaptic neuron-the neuron sending the message

postsynaptic neuron-the neuron receiving the message

Question 24

The process of releasing neurotransmitters and opening ion channels:

1)
2) synaptic knobs release packets of neurotransmitter into the synaptic cleft
3) neurotransmitter diffuses across the synaptic cleft
4) neurotransmitter binds with receptors on the membrane of the postsynaptic neuron
5) when a neurotransmitter binds to its receptor, an ion channel is opened
6) sodium ions enter the postsynaptic neuron, causing depolarization and possible action potential

Answer 24

1) the nerve impulse reaches the axon ending of the presynaptic neuron

Question 25

The process of releasing neurotransmitters and opening ion channels: 1) the nerve impulse reaches the axon ending of the presynaptic neuron 2) 3) neurotransmitter diffuses across the synaptic cleft 4) neurotransmitter binds with receptors on the membrane of the postsynaptic neuron 5) when a neurotransmitter binds to its receptor, an ion channel is opened 6) sodium ions enter the postsynaptic neuron, causing depolarization and possible action potential

Answer 25

2) synaptic knobs release packets of neurotransmitter into the synaptic cleft

Question 26

The process of releasing neurotransmitters and opening ion channels: 1) the nerve impulse reaches the axon ending of the presynaptic neuron 2) synaptic knobs release packets of neurotransmitter into the synaptic cleft 3) 4) neurotransmitter binds with receptors on the membrane of the postsynaptic neuron 5) when a neurotransmitter binds to its receptor, an ion channel is opened 6) sodium ions enter the postsynaptic neuron, causing depolarization and possible action potential

Answer 26

3) neurotransmitter diffuses across the synaptic cleft

Question 27

The process of releasing neurotransmitters and opening ion channels: 1) the nerve impulse reaches the axon ending of the presynaptic neuron 2) synaptic knobs release packets of neurotransmitter into the synaptic cleft 3) neurotransmitter diffuses across the synaptic cleft 4) 5) when a neurotransmitter binds to its receptor, an ion channel is opened 6) sodium ions enter the postsynaptic neuron, causing depolarization and possible action potential

Answer 27

4) neurotransmitter binds with receptors on the membrane of the postsynaptic neuron

Question 28

The process of releasing neurotransmitters and opening ion channels: 1) the nerve impulse reaches the axon ending of the presynaptic neuron 2) synaptic knobs release packets of neurotransmitter into the synaptic cleft 3) neurotransmitter diffuses across the synaptic cleft 4) neurotransmitter binds with receptors on the membrane of the postsynaptic neuron 5) 6) sodium ions enter the postsynaptic neuron, causing depolarization and possible action potential

Answer 28

5) when a neurotransmitter binds to its receptor, an ion channel is opened

Question 29

The process of releasing neurotransmitters and opening ion channels: 1) the nerve impulse reaches the axon ending of the presynaptic neuron 2) synaptic knobs release packets of neurotransmitter into the synaptic cleft 3) neurotransmitter diffuses across the synaptic cleft 4) neurotransmitter binds with receptors on the membrane of the postsynaptic neuron 5) when a neurotransmitter binds to its receptor, an ion channel is opened 6)

Answer 29

6) sodium ions enter the postsynaptic neuron, causing depolarization and possible action potential

Question 30

__________ is the combined effects of excitatory and inhibitory effects on a neuron at any given moment determines whether an ______ _________ is generated

Answer 30

Summation | action potential

Question 31

Summation is the combined effects of ________ and _________ effects on a neuron at any given moment determines whether an action potential is generated

Answer 31

excitatory | inhibitory

Question 32

True or False: After being released into a synapse, neurotransmitters are quickly removed, so their effects are temporary

Answer 32

True

Question 33

Depending on the neurotransmitter, disposal is accomplished in one of what 2 ways?

Answer 33

1) enzymes can deactivate a neurotransmitter | 2) the neurotransmitter may be actively pumped back into the presynaptic knob

Question 34

____________, __________, and ____________ are neurotransmitters used in both peripheral and central nervous system.

Answer 34

Acetylcholine epinephrine norepinephrine

Question 35

Acetylcholine, epinephrine, and norepinephrine are neurotransmitters used in both _________ and ______ _______ system.

Answer 35

peripheral | central nervous

Question 36

Both ___________ and ____________ have either excitatory or inhibitory effects

Answer 36

Acetylcholine | norepinephrine

Question 37

Both Acetylcholine and norepinephrine have either ________ or ________ effects

Answer 37

excitatory | inhibitory

Question 38

Which neurotransmitter is this: stimulates most organs but inhibits certain others

Answer 38

norepinephrine

Question 39

Which neurotransmitter is this: will have the opposite of Acetylcholine

Answer 39

norepinephrine

Question 40

Which neurotransmitter is this: mood regulation

Answer 40

norepinephrine

Question 41

Which neurotransmitter is this: pleasure system

Answer 41

norepinephrine

Question 42

Which neurotransmitter is this: arousal

Answer 42

norepinephrine

Question 43

Which neurotransmitter is this: essential in hunger, thirst, and sex drive

Answer 43

norepinephrine

Question 44

Which neurotransmitter is this: triggers contraction of voluntary (skeletal) muscle

Answer 44

Acetylcholine

Question 45

Which neurotransmitter is this: promote a generalized feeling of well-being

Answer 45

serotonin

Question 46

Which neurotransmitter is this: helps regulate emotions

Answer 46

dopamine

Question 47

Which neurotransmitter is this: used in pathways that control complex movements

Answer 47

dopamine

Question 48

What is myasthenia gravis?

Answer 48

an autoimmune disease in which the body’s defense mechanisms attack the acetylcholine receptors at neuromuscular junctions

Question 49

Postsynaptic cells integrate _________ and ________ input from many cells

Answer 49

excitatory | inhibitory