Lesson 2

Question 1

There are so many things that your mind and brain does. Can you name three?

Answer 1

• sense, perceive, understand the world
• learn and remember
• plan, organize, and perform complex actions
• love, hate, fear, appreciate music
• strive for world peace

Question 2

What is the brain made of?

Answer 2

89 billion cells called neurons, the wiring that connects them and alot of glial cells

Question 3

what are the molecules called that are present in your brain?

Answer 3

neurotransmitters

Question 4

What are the cells of the brain called?

Answer 4

neurons

Question 5

what is a collections of neurons called?

Answer 5

assemblies or neural circuits

Question 6

what do larger collections of neurons make up?

Answer 6

brain areas

Question 7

Brain areas connect to each other in _______ forming _________

Answer 7

networks; neural systems

Question 8

fill in the blanks

Answer 8

Question 9

where does the communication between other neurons occur?

Answer 9

the terminal buttons

Question 10

What kind of process is neural activity?

Answer 10

an electro-chemical process

Question 11

which part of neural activity refers to the flow of ions
(charged particles) in/out of the cell, or through the cell?

Answer 11

the electrical part

Question 12

which part of neural activity refers to the flow of
neurotransmitters between neurons?

Answer 12

the chemical part

Question 13

what are the key ions for a neuron membrane?

Answer 13

sodium (Na+)
potassium (K+)
chloride (Cl-)

Question 14

what is the charged value of the neuron membrane?

Answer 14

-70mv

Question 15

what is something a neuron membrane is able to do that involves ions?

Answer 15

is able to decide what to keep in and out of the cell

Question 16

how do you describe a neuron membrane?

Answer 16

semi-permeable

Question 17

what is the resting membrane potential?

Answer 17

the difference in charge across the membrane at equilibrium (about -70mv)

Question 18

what are the three stages of computation in a neuron?

Answer 18

stage 1: input stage
stage 2: “processing” stage
stage 3: output stage

Question 19

between two neurons, there is a ______ where the axon of one neuron connects to the dendrite of another neuron

Answer 19

synapse

Question 20

the neuron before the synapse is called?

Answer 20

presynaptic neuron

Question 21

the neuron after the synapse is called?

Answer 21

postsynaptic neuron

Question 22

what do we called when a neuron fires?

Answer 22

the action potential

Question 23

before a transmitter release the postsynaptic neuron is ___ at rest

Answer 23

polarized meaning it has a negative charge

Question 24

after a transmitter release, ion channels are influenced and the postsynaptic cell has been _____

Answer 24

depolarized meaning it ends up with a less negative charge

Question 25

What type of potential describes when the cell is less polarized because it has a less negative charge?

Answer 25

Excitatory postsynaptic potential (EPSP)

Question 26

What type of potential describes when the cell can also become more polarized so it has a more negative charge?

Answer 26

Inhibitory postsynaptic potential (IPSP)

Question 27

What is the word for when a cell is less polarized?

Answer 27

depolarized

Question 28

What is the word for when a cell is more polarized?

Answer 28

hyper polarized

Question 29

Why is depolarization is excitation?

Answer 29

because it makes it more likely the cell will reach threshold (e.g., -50mv) and trigger an action potential

Question 30

Why is hyperpolarized inhibition?

Answer 30

because it makes it less likely the cell will reach threshold and transmit a signal (via an action potential)

Question 31

What are examples of excitatory neurotransmitters?

Answer 31

ACh, catecholamines, glutamate, serotonin

Question 32

What are examples of inhibitory neurotransmitters?

Answer 32

GABA, glycine, some peptides

Question 33

How do neurotransmitters fit post-synaptic receptors?

Answer 33

in a 'lock and key' fashion

Question 34

True or False? if false, correct the statement specific neurotranmitters fit with specific receptors

Answer 34

true

Question 35

What are the four steps of the input stage?

Answer 35

1. Presynaptic neuron releases neurotransmitters into synaptic cleft 2. Neurotransmitters bind with receptor of the post-synaptic cell in a lock and key fashion 3.Ion channels in the post-synaptic cell open at the receptor site allowing specific ions to enter the cell 4. Depending on the neurotransmitter and receptor, post-synaptic cell becomes depolarized or hyperpolarized

Question 36

Fill in the blank: the right neurotransmitter must be with the right ____to have influence on the post-synaptic cell

Answer 36

Receptor

Question 37

Fill in the blank: The synapse is where the ____ of one neuron connects to the ____ of another neuron

Answer 37

terminal button; dendrite

Question 38

Where do signals from other neurons enter?

Answer 38

dendrites

Question 39

What stage matches this description: many “signals” come in at the dendrites

Answer 39

the input stage

Question 40

What stage matches this description: signals summate, adding and canceling, possibly reaching critical threshold within the cell body

Answer 40

the "processing" stage

Question 41

What stage matches this description: if the input is strong enough (exceeds threshold) then the neuron passes the signal along via it’s axon

Answer 41

Output stage

Question 42

where does evaluation process happen? with importance to which region?

Answer 42

the cell body; the axon hillock

Question 43

As more information comes into the post synaptic neuron?

Answer 43

the overall charge of the neuron increases

Question 44

When the threshold of -50mv is reached, what happens?

Answer 44

voltage sensitive gates open up, triggering a positive spike in voltage (an “action potential”)

Question 45

Which region of the neruon is where the axon connects to the cell body?

Answer 45

axon hillock

Question 46

What word is defined as the value of the membrane potential?

Answer 46

the threhold

Question 47

What word is defined as a dramatic change in voltage to a positive potential (+40mv), to below resting potential, then back to resting potential (-70mv)

Answer 47

the action potential

Question 48

True or false? if false, correct the statement Action potentials do vary in strength, but can't vary in rate

Answer 48

False; action potentials do not vary in strength, but they can vary in rate

Question 49

True or false? if false, correct the statement All-or-none is defined as the value of the action potential is always the same, regardless of the amplitude of the depolarizing current

Answer 49

true

Question 50

True or false? if false, explain why A threshold of -50mv is a weak action potential and a threshold of -30mv is a strong action potential

Answer 50

action potential don't vary in strength. there are no "strong" or "weak" action potentials

Question 51

Fill in the blank: Signals are transmitted along the ______, until they reach _______, where they connect to the next ______

Answer 51

axon; terminal buttons; neuron

Question 52

True or false? if false, explain why When more information is coming in resulting in more frequent action potentials, this is an example of the rate changes and is not characterized by strengths

Answer 52

true, actions potential aren't characterized as strong or weak but the rates can change

Question 53

what is the purpose of myelin sheath?

Answer 53

provides electrical insulation, alters the flow of current down the axon

Question 54

Since action potentials cannot be generated where there are myelin sheaths, where do action potentials happen?

Answer 54

the nodes of Ranvier, breaks in the myelin sheaths

Question 55

What is saltatory conduction?

Answer 55

in myelinated action potentials “jump” from node to node, enabling fast propagation of the signal down the axon, with a signal that never loses strength at any distance

Question 56

During saltatory conduction, does a signal lose strength at any distance?

Answer 56

No

Question 57

What is the threshold reached at the axon hillock to open voltage sensitive gates and trigger an action potential?

Answer 57

-50mv

Question 58

True or false? if false explain why An action potential triggered by a value of membrane potential of -35mv is stronger than an action potential triggered by a membrane potential of -50mv

Answer 58

false; action potentials aren't described as strong or weak