exam 1 Flashcards
1
Q
3
A
Rising phase of Action Potential
2
Q
2
A
Depolarization leading up to the start of an action potential
3
Q
1
A
Resting potential
4
Q
5
A
undershoot
5
Q
4
A
Falling phase of the action potential
6
Q
K+ gates are still open, allowing some K+ to continue moving out a little, Na+ gates are closed.
A
5
7
Q
K+ gates are open allowing K+ to rush inside the cell.
A
4
8
Q
Na+ gates are closed, K+ gates are mostly closed.
A
1
9
Q
Most of the Na+ gates are open allowing Na+ to rush into the cell.
A
3
10
Q
A stimulus opens the gates of some Na+ channels letting some Na+ into the cell.
A
2
11
Q
White matter is mainly made of…
A
Fat and Myelinated axons
12
Q
Gray matter:
A
Is mainly somas and dendrites; can be cortical or subcortical
13
Q
Gyrus
A
An outward fold of the cortex
14
Q
Sulcus
A
an inward fold of the cortex
15
Q
Gyri
A
Several outward cortical folds
16
Q
Sulci
A
several inward cortical folds
17
Q
Dura mater
A
tough membrane enveloping the brain and spinal cord
18
Q
Ventricle
A
fluid filled cavity in the brain
19
Q
Superior or Dorsal
A
toward the top
20
Q
Ventral or inferior
A
toward the bottom
21
Q
lateral
A
away from the midline
22
Q
medial
A
toward the midline
23
Q
anterior or rostral
A
toward the front
24
Q
posterior or caudal
A
toward the back
25
What kind of plane is this?
coronal
26
What is F?
- Subcortical
- Part of the cerebral cortex
- Mostly somas and dendrites
- A sulcus
- White matter
- A gyrus
Part of the cerebral cortex; Mostly somas and dendrites; A gyrus; Grey matter
27
what is C?
- Mostly somas and dendrites
- Subcortical
- A ventricle
- Mostly myelinated axons
- Part of the cerebral cortex
- Grey matter
Mostly somas and dendrites; Subcortical; Grey matter
28
What is H?
- Cerebral cortex
- White matter
- Dura mater
- Grey matter
- A meninges
- A ventricle
A ventricle; Normally field with cerebral spinal fluid
29
Which human sulcus is analogous to the cruciate fissure in sheep.
central sulcus
30
The _____________ is just caudal to the central sulcus in the _____________.
postcentral gyrus, parietal lobe
31
The _________________ is just anterior to the central sulcus in the _______________.
precentral gyrus, frontal lobe
32
The precentral gyrus is also called _____________________ which describes it's function.
primary motor cortex or M1
33
The postcentral gyrus is also called __________________ which describes it's function.
primary somatosensory cortex or S1
34
In which lobe is primary visual cortex located?
occipital lobe
35
Broca's area is in the __________________ and primary auditory cortex is in the _______________.
frontal lobe, temporal lobe
36
f
postcentral gyrus (primary somatosensory cortex)
37
w
precentral gyrus (primary motor cortex)
38
n
parietal lobe (minus the post central gyrus)
39
R
frontal lobe (minus precentral gyrus)
40
C
occipital lobe
41
D
temporal lobe
42
H
cerebellum
43
Which is NOT true of an EPSP?
It is all or none.
It increases the likelihood of an action potential.
It is a graded potential.
It is a positive increase in voltage inside the cell.
It is all or none
44
A reflex arc is the path that a neural signal takes from a sensory receptor to the muscle. Sherrington found that the speed of conduction of this signal along a reflex arc was:
slower than along an axon without any synapses.
45
Temporal summation:
occurs when two or more post-synaptic potentials produced by a single pre-synaptic neuron occur in close succession and add together to influence the post-synaptic neuron.
46
What was in the liquid that Otto Loewi transferred from one frog heart to another that caused the second heart to slow down?
neurotransmitter molecules
47
A neurotransmitter that causes sodium ions to flow through it's receptor into the post-synaptic neuron would
be exictatory
48
Which of these is true when a neurotransmitter binds to a receptor and immediately causes chloride ions (Cl-) to enter the post-synaptic cell? Select ALL the answers that apply, not just one answer.
- It is excitatory.
- It hyperpolarizes the neuron.
- The effect is ionotropic.
- It is inhibitory.
- It depolarizes the neuron.
- The effect is metabotropic.
It hyperpolarizes the neuron; The effect is ionotropic; It is inhibitory.
49
Second messengers activated by metabotropic receptors in the post-synaptic neuron can:
change the activity of proteins in the cell; open ion channels; alter gene expression
50
A drug can alter the activity at a synapse by changing:
the storage of neurotransmitters
binding directly to the receptor and either activate it or block the real neurotransmitter from binding and activating it
the rate at which the neurotransmitters in the synaptic cleft are inactivated
the synthesis of neutransmitters; how quickly neurotransmitters are reuptaken by the pre-synaptic cell
the release of neurotransmitters
51
Which of these is the correct order of brain regions along the reward pathway?
Ventral Tegmental Area, Nucleus Accumbens, Prefrontal Cortex
52
Prior to the work of Santiago Ramon y Cajal, what did many investigators believe?
The tip of an axon physically merged with the next neuron
53
What structure is composed of two layers of fat molecules that are free to flow around one another?
the membrane
54
Chemicals than cannot flow freely across a cell membrane enter a neuron through:
specialized protein channels.
55
Where do the metabolic activities occur that provide energy for all of the other activities of the cell?
Golgi complexes
56
Ribosomes are the part of a cell that:
synthesizes new proteins.
57
One of the most distinctive features of neurons compared to other types of cells is their:
shape
58
What receives excitation from other neurons and conducts impulses to muscle or gland cells?
dendritic spines
59
What receives excitation from other neurons and conduct impulses to muscle or gland cells?
Sensory neurons
60
The tree-like branches of a neuron that receive information from other neurons are called:
dendrites
61
The information sender of the neuron, conveying an impulse toward either other neurons or a gland or muscle is called the
axon
62
Compared to dendrites, axons usually:
are covered with myelin
63
The insulating material which covers many vertebrate axons is called the:
myelin sheath
64
Which of the following is NOT true of axons?
They carry information toward the soma.
They can vary greatly in length.
Some of them are covered with myelin sheaths.
They release chemicals that cross the synapse.
They carry information toward the soma.
65
What is the point from which an axon releases chemicals into the synapse?
the presynaptic terminal
66
An axon releases chemicals:
into the junction between neurons
67
What type of glial cells myelinate axons in the brain and spinal cord?
astrocytes
68
Which function is NOT performed by glia?
building myelin sheaths
guiding the growth of axons and dendrites
removing waste materials
transmitting information
transmitting information
69
Which type of glia builds myelin sheaths around axons in the periphery of the body?
Schwann cells
70
The risk of having part of the brain unprotected by the blood-brain barrier is:
viruses or toxic chemicals are more likely to damage it.
71
Drugs can cross the blood-brain barrier if they are soluble in:
fats
72
How does glucose enter the brain?
It is pumped in by an active transport system.
73
Compared to passive transport, the major disadvantage of active transport is that it:
requires expenditure of energy
74
When you state that the neuron's membrane is polarized, you are referring to a difference in electrical potential between:
the inside and the outside of the membrane.
75
What is the approximate resting potential of the inside of a neuron's membrane, relative to the outside?
-70 millivolts
76
When a neuron's membrane is at rest, which of the following molecules crosses through it MOST slowly?
Sodium
77
When a neuron’s membrane is at rest, the concentration gradient tends to move sodium ____ the cell and the electrical gradient tends to move it ____ the cell. (into or out of)
into, into
78
When a neuron’s membrane is at rest, the concentration gradient tends to move potassium ____ the cell and the electrical gradient tends to move it ____ the cell.
(answer into or out of)
out of, into
79
The net effect of each cycle of the sodium-potassium pump is to:
decrease the number of positively charged ions within the cell.
80
What is one major cause for the resting potential of a neuron's membrane?
the sodium-potassium pump
81
The sodium-potassium pump pumps sodium ions ____ and potassium ions ____.
out of the cell; into the cell
82
Concentration gradients lead to what kind of movements?
the movement of ions to areas of their lowest concentrations
83
When the neuron is at rest, what is responsible for moving potassium ions OUT of the cell?
a concentration gradient
84
When the neuron is at rest, what is responsible for moving sodium ions out of the cell?
the sodium-potassium pump
85
Which of the following is an advantage of having a resting potential?
No energy is required to maintain it.
All of the ions are maintained in equal concentrations throughout the cytoplasm.
The toxic effects of sodium are minimized inside the cell.
The cell is prepared to respond quickly to a stimulus
The cell is prepared to respond quickly to a stimulus.
86
```
Ordinarily, stimulation of a neuron takes place:
through hyperpolarization.
in the endoplasmic reticulum.
at the synapse.
in the mitochondria.
```
in the endoplasmic reticulum
87
What is the result if a stimulus shifts the potential inside a neuron from the resting potential to a more negative potential?
hyperpolarization
88
What is the result if a stimulus shifts the potential inside a neuron from the resting potential to a potential slightly closer to zero?
depolarization
89
If there is a depolarizing effect on a neuron, the result will be that the neuron will fire:
only if it reaches the threshold
90
Stimulus A depolarizes a neuron just barely above the threshold. Stimulus B depolarizes a neuron to 10 mV beyond threshold. What can we expect to happen?
Stimulus A and stimulus B will produce the same response in the neurons.
Stimulus B will produce an action potential but stimulus A will not.
Stimulus B will produce an action potential that is conducted at a faster speed than A.
Stimulus B will produce an action potential of greater magnitude than stimulus A.
Stimulus A and stimulus B will produce the same response in the neurons.
91
At the peak of the action potential, the electrical gradient of potassium:
is the same as during the resting potential.
pulls sodium into the cell.
pulls potassium into the cell.
pushes potassium out of the cell.
pushes potassium out of the cell
92
A drug that blocks the sodium gates of a neuron's membrane would:
decrease the threshold.
block the action potential.
cause repeated action potentials.
eliminate the refractory period
block the action potential
93
At what point do the sodium gates begin to close, shutting out further entry of sodium into the cell?
at the peak of the action potential
94
ust after the peak of the action potential, what movement of ions restores the membrane to approximately the resting potential?
Potassium ions enter the cell.
Potassium ions leave the cell.
Sodium ions enter the cell.
Sodium ions travel down the axon.
potassium ions leave the cell
95
What causes potassium ions to leave the axon just after the peak of the action potential?
binding of potassium ions to proteins that leave at this time
an increase in the concentration gradient across the membrane
a continuing concentration gradient and the opening of the potassium gates
a continuing concentration gradient and the opening of the potassium gates
96
The presence of an all-or-none law suggests that neurons can only convey different messages by changing their:
rate or pattern of action potentials.
size of action potentials.
sodium-potassium pump activity.
speed of action potentials.
rate or pattern of action potentials.
97
Under what conditions is it impossible for a stimulus to produce an action potential?
if it occurs at the same time as a hyperpolarizing stimulus
if sodium ions are more concentrated outside the cell than inside
if the potassium gates have been blocked
if the membrane is in its absolute refractory period
if the membrane is in its absolute refractory period
98
Where do most action potentials begin?
in the dendrites
in the cell body
at the tip of the axon
at the axon hillock
at the axon hillock
99
What happens once an action potential starts?
It increases in speed as it goes.
It is regenerated at other points along the axon.
It is conducted the rest of the way as an electrical current.
It needs additional stimulation to keep it going along the axon
It is regenerated at other points along the axon
100
What is to prevent an action potential from exciting the area behind it and starting a "rebound" action potential traveling the opposite direction?
the refractory period
101
What disease is related to the destruction of myelin sheaths?
multiple sclerosis
102
What disease is related to the destruction of myelin sheaths?
multiple sclerosis
103
In the neuron pictured below, B is the
soma
104
What makes nitric oxide unique among neurotransmitters?
it is a gas
105
On the basis of what evidence did Charles Sherrington first infer the properties of synapses?
behavioral observations
106
Which of the following statements regarding reflexes would Charles Sherrington most likely agree with?
Repeated stimuli occurring within a brief time can have a cumulative effect.
107
Which of the following is true about EPSPs?
It takes two to produce an action potential.
They can be either excitatory or inhibitory.
They decay over time and space.
They occur because potassium gates open.
they decay over time and space
108
Depolarization is to ________ and hyperpolarization is to ________.
109
The primary difference between an EPSP and an action potential is that
EPSPs are subthreshold events that decay over time and space.
110
Which of the following might produce spatial summation?
Present two or more weak stimuli at the same time
Do not allow a flexor muscle to relax before stimulating it again
Present a rapid sequence of weak stimuli
Start action potentials at both ends of one axon at the same time
Present two or more weak stimuli at the same time
111
A normal, healthy animal never contracts the flexor muscles and the extensor muscles of the same leg at the same time. Why not?
When the interneuron sends excitatory messages to one, inhibitory messages go to the other
112
What is the synaptic cleft?
The gap between the presynaptic neuron and the postsynaptic neuron
113
What is the synaptic cleft?
The gap between the presynaptic neuron and the postsynaptic neuron
114
The neurotransmitter GABA exerts ________ effects by opening gates that allowing Cl- into the cell. This effect is ________.
ionotropic; inhibitory
115
"Second messengers" are activated by a metabotropic neurotransmitter and carry their messages to:
areas within the postsynaptic cell
116
What is the function of the enzyme acetylcholinesterase?
It breaks acetylcholine down into components for recycling
117
A drug that blocks the effects of a neurotransmitter is a(n) ________; a drug that mimics or increases the effects is a(n) ________.
antagonist; agonist
118
Why do the effects of certain transmitters, such as serotonin, vary from one synapse to another?
There are several kinds of postsynaptic receptors for serotonin
119
Opiate drugs bind to receptors in the brain for
endorphins
120
Which drugs most closely resemble the neurotransmitter serotonin
hallucinogens
121
In the neuron pictured below, C is the the
axon
122
The blood brain barrier is
a membrane surrounding the brain like a sack.
123
__________ is the proportion of observed differences in a trait among individuals in population that is due to genetic differences between the individuals.
heritability
124
_____ are large molecules, usually proteins, that act as biological catalysts, dramatically speeding up specific chemical reactions.
Enzymes
125
one parent is homozygous dominant for a gene and the other is homozygous for a recessive, what percentage of the children will display the dmoninant trait?
75%
126
_____ is the study of the microscopic anatomy of cell and tissues. It is usually performed by slicing and staining biological samples and examining them under a microscope.
histology
127
Sodium (Na+) and potassium (K+) ions are crucial for creating the resting potential and the action potential. Which one is most concentrated outside a neuron during the resting potential?
Sodium
128
Sensory information comes in which side of the spinal cord?
dorsal
129
Why do we have finer discrimination of touch signals in the hand compared to, say, the lower back?
We have more cortex devoted to processing information from the hands.
130
Anterograde tracers:
(choose all answers that apply)
- Are a kind of stain.
- Are carried along the axon in the direction of the action potential.
- Are carried along the axon in the opposite direction of the action potential.
- Help show how brain areas are connected to each other.
Are a kind of stain; Are carried along the axon in the direction of the action potential; Help show how brain areas are connected to each other
131
Immunohistochemistry or immunocytochemistry:
(choose all answers that apply)
- Allows scientists to see how chemicals or cell types are distributed in body tissues
- Are words I just totally made up to mess with you.
- Shows the action potential activity in neurons.
- Can reveal patterns of protein expression.
Allows scientists to see how chemicals or cell types are distributed in body tissues; Can reveal patterns of protein expression
132
Single cell recording:
(choose all answer that apply)
- Is also known as single unit recording.
- Measures the gene expression pattern within a single cell.
- Is usually done in humans.
- Records the action potentials generated by one neuron,
Is also known as single unit recording; Records the action potentials generated by one neuron
133
What happened when Prof. Young cut the large tubular structure (the giant axon) running down the center of the nerve?
The part of the mantle served by the nerve no longer showed large contractions.
134
What did Prof. Young use to stimulate the nerve?
an electrode
135
Why was finding this giant axon so important?
It was large enough to investigate using the techniques available at the time.
136
When they squeezed the contents out of the axon, what did they discover?
Potassium was more concentrated inside than outside.
137
Unraveling the mechanisms of the action potential allowed the development of what?
local anesthetics
