09/11 Flashcards

1
Q

What are the different ways to classify a neuron?

A

Size
Myelenation states

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a A neuron?

A

a heavily myelinated neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a B neuron?

A

a lightly myelinated neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a C neuron?

A

a non-myelinated neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the biggest size a neuron diameter can be?

A

20 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the smallest size a neuron diameter can be?

A

0.5mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Important information is usually sent through

A

a bigger, myelinated neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Motor functions are sent through

A

bigger, myelinated neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Less important information is usually sent through

A

smaller, less myelinated neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are examples of the less important information that is sent via neurons?

A

Tickle
Cold
Warmth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Myelinated (A fibers) are subdivded into what categories?

A

Alpha
Beta
Gama
Delta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the largest subcategory of an A neuron?

A

alpha

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Rank the A neuron subunits from smallest to largest

A

Delta<Gama<Beta<Alpha

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

All neurons have a

A

Cell body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is another name for the cell body in a neuron?

A

Soma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the projections from the cell body called?

A

Dendrites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Can dendrites connect to the cell body?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Excitatory connections on the dendrites create a more ______ membrane potential

A

postive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Inhibitory connections on the dendrites create a more ______ membrane potential

A

negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the projection from the soma that an action potential moves down called?

A

Axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Is the axon hillock more negative or more positive?

A

more Negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Most axons are

A

myelinated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is a presynaptic terminal?

A

The very end of an axon before it connects to a target

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the “brakes” in the nervous system?

A

Axon hillocks and Chloride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the neurotransmitter that is used on the axon hillock?

A

GABA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does GABA do in the axon hillock?

A

Increases permeability to Cl-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

If we remove all of our endogenous GABA, what would happen?

A

We would have seizures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is an example of something that removes all of our natural GABA?

A

Alcoholism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is GABA mediated neurotransmission?

A

Endogenous GABA that increases permeability to Cl- which makes the cell more negative.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the concentration gradient of Cl-?

A

higher on the outside, lower on the inside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why don’t we have outside excitation at the axon hillock?

A

It would bypass the soma making the soma irrelevant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the 2 main categories of brain cells?

A

Neurons
Glial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which brain cell proliferates the fastest?

A

glial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the smallest glial cell?

A

microglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the macroglial cells?

A

Astrocytes
ependymal
oligodentrocytes
-schwann

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

why are astrocytes named astrocytes?

A

They are shaped like a star

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is a big part of the functional BBB?

A

Astrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Where is one place that astrocytes connect to?

A

to the outside of an endothelial cell on a capillary
It wraps itself around the true part of the BBB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How are astrocytes oriented where it connects to capillaries?

A

It wraps itself around the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Where is the BBB found?

A

in between the capillaries of our endothelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is the true part of the BBB?

A

the tight junctions between endothelial cells an capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What is one thing that astrocytes are very good at?

A

maintaining electrolytes in the CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

If there is an excess of electrolytes in the CSF, what happens?

A

The electrolytes can be tucked away in the astrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are the 3 main functions of astrocytes?

A

Supportive structure for the BBB
Regulate electrolytes in the CSF
Maintain the pH of the CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Where are astrocytes found?

A

surrounding the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are on ependymal cells?

A

cillia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What is the function of ependymal cells?

A

Producing and moving of CSF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Where is the main place CSF is made?

A

ependymal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What are the myelin producing cells in the CNS?

A

oligodendroctyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What forms the myelin sheath in the PNS?

A

Schwann cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What is the function of the microglial cells?

A

Act as macrophages and work as the immune system in the CSF, keeping the area clean and free from debris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What are the decision making cells?

A

multipolar neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What does a multipolar neuron look like?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What decisions do multipolar neurons make?

A

to send an action potential or not

54
Q

What is the best example of the bipolar neuron?

A

type of photoreceptors in a retina that send messages through the optic nerve

55
Q

What does a bipolar neuron look like?

A
56
Q

Bipolar neurons are typically used for what?

A

specialized senses (optic nerve)

57
Q

Bipolar neurons are primarily sensory, meaning they don’t require a lot of connections to other cells. This designed is set up to

A

sense information and then pass that information as action potentials to some other area of the brain.

58
Q

What are the majority of the sensory cells that are found immediately outside of the spinal cord?

A

Pseudounipolar neurons

59
Q

Where are the decisions made in relation to a pseudounipolar neuron?

A

the sensor itself

60
Q

What does the soma of a unipolar neuron exist for?

A

as a place to build proteins and replace things that need to be maintained within the neuron

61
Q

What is an example of a multipolar neuron?

A

a motor neuron

62
Q

Where are true unipolar neurons found?

A

in lower life forms, not in humans

63
Q

What is somatic sensation?

A

Consciously discernable sensations

64
Q

Free nerve endings are what type of sensor?

A

pain

65
Q

what’s another term for a pain receptor?

A

nociceptor
free nerve ending

66
Q

More distortion or stretch on a pressure sensor equals

A

more sodium entering the cell and more action potentials that will be fired

67
Q

What is a mechanoreceptor?

A

a sensor that takes some kind of physical environmental disturbance and turns that into an electrical signal

68
Q

What is an example in adaptability?

A

a baro receptor that adjusts it’s action potentials to a high map so that the body recognizes the prolonged BP as normal.

69
Q

How long does it take for baroreceptors to recognize an elevated BP as “normal”

A

2 days

70
Q

What is reverse adaptation?

A

When you have a stimulus for an extended period of time, and instead of the body recognizing it as normal, the body ramps up the action potentials

71
Q

What are examples of sensory receptors?

A

Pacinian corpuscle
Meissner’s corpuscle
Golgi tendon apparatus
muscle spindle

72
Q

How are muscle spindles oriented?

A

they wrap around muscles.

73
Q

What do muscle spindles tell us?

A

If a muscle has completed the task it was supposed to do

74
Q

A stimulation has to reach ______ to create an action potential

A

threshold

75
Q

What is threshold?

A

The bar that depolarization has to get over to.

76
Q

If we just barely depolarize over threshold, what will result?

A

An action potential will occur after a little bit of time has passed

77
Q

What makes the plateau in the top of a cardiac action potential?

A

Slow Ca++ channels opening slowly after depolarization.

78
Q

When chloride channels are open, what does chloride do?

A

Comes into the cell down it’s concentration gradient and makes it more negative

79
Q

what ion keeps the brakes on the nervous system?

A

chloride

80
Q

ca++ coming into the cell is going to be

A

stimulatory

81
Q

calcium is

A

large and charged

82
Q

how does calcium contribute to the cell becoming more negative?

A

It sits in the Na+ leak channel openings and blocks Na+ from entering

83
Q

how does hypocalcemia contribute to a more excitable cell?

A

The less Ca++ molecules there are to block the Na+ leak channels, the more Na+ is going to go into the cell and make it positive

84
Q

What can you give to a hyperkalemic person to help decrease their cell’s excitability? why?

A

Ca++
Ca++ blocks leaky Na+ channels meaning less Na+ can come in

85
Q

Calcium’s effect on a resting cell is typically

A

inhibitory, slows down irritable tissue, and stabilized membrane potential

86
Q

Why doesn’t Ca++ block K+ channels?

A

K+ pushes Ca++ out of the way if it settles on the channel

87
Q

If a motor neuron is not surrounded by a normal amount of Ca++, what is the result?

A

The motor neuron is more + and excitable leading to more contractility of the skeletal muscle

88
Q

What causes Trousseau’s sign?

A

Hypocalcemia. Less Ca++ being available around motor neurons, making the neurons more +++ because Na+ is coming into the cell. This hyperactivity leads to the hyperactivity of skeletal muscles. This causes Tetany

89
Q

What is the Chvostek’s sign named after?

A

A Russian guy

90
Q

Does Ca++ effect fast Na+ channels?

A

No, only the leaky Na+ at rest

91
Q

What is an ion besides Ca++ that helps settle down an excited cell by hyperpolarizing a Vrm?

A

Mg++
Not sure how

92
Q

What are some things that effect AP propagation?

A

Length of the nerve
diameter of the nerve

93
Q

What are the properties of a neuron that sends action potentials quickly?

A

Short, wide, and insulated

94
Q

How does a schwann cell orient itself?

A

It wraps itself in a spiral around a neuron.
The layers are compacted, pushing out the water that was in the cell originally becoming a good insulator.

95
Q

A Schwann cell is a

A

lipid compound

96
Q

What are 2 ways to speed up an action potential?

A

Increase VG Na+ channels
Decrease the amount of Na+ being pumped out

97
Q

How does a neuron decrease the amount of Na+ leaving the cell?

A

It insulates the outside of the cell with myelin, making it so that Na+ is blocked from leaving the cell

98
Q

What are 2 things that myelin does?

A

Speeds up propagation of action potentials
Creates a more efficient cell

99
Q

Why is reduced ATP requirements a good thing in a neuron?

A

If we have a block that isn’t allowing blood to feed the neuron, it gives it a little longer survival because it doesn’t need as much energy

100
Q

What are the spaces between the myelin called?

A

Nodes of Ranvier

101
Q

What is found in the nodes of ranvier?

A

Lots of fast sodium channels, K+ channels, and Na+/K+ pumps

102
Q

Which type of neuron is harder to anesthetize? why?

A

a myelinated neuron
Because it has a really high fast sodium channel density located at the nodes of ranvier

103
Q

What is saltatory conduction?

A

The jumping pattern of Na+ going from one node of ranvier to the next and exciting more fast Na+ channels, allowing more Na+ into the cell

104
Q

What helps protect neurons from crush injuries?

A

myelin. It protects the neuron by providing robustness

105
Q

What is included in the CNS?

A

Brain
spinal cord
cranial nerve 2 (optic nerve)
retinas

106
Q

What are the cells called in the CNS that maintain and produce myelin?

A

oligodendrocytes

107
Q

What is included in the PNS?

A

everything outside of the spinal cord

108
Q

What cells are found in the PNS that maintain and produce myelin?

A

Schwann cells

109
Q

Are oligodendrocytes easy to replace?

A

no

110
Q

If we lose myelin around our optic nerve, we may have

A

cloudy or delayed vision, or loss of peripheral vision

111
Q

When did Giullain-Barre syndrome spike and why?

A

after covid, because antibodies were made against covid and were not just specific to covid. they also reacted with the nervous system

112
Q

What is MS

A

multiple sclerosis
a demyelinating disease that happens in our motor system

113
Q

How does MS work?

A

Over time, the fast Na+ channels and K+ channels disappear underneath the myelin sheaths leaving only the high density areas at the node of ranvier. Na+/K+ pump do repopulate under the myelination.
In MS when the myelination is gone, the movement of Na+ downstream is stunted by the Na+ being pumped out during the whole length of where the myelin used to be.
The action potential can no longer reach it’s target, the muscle, which can lead to paralysis

114
Q

Does Guillain-Barre last forever?

A

No, it goes away over time

115
Q

What causes demyelinating diseases?

A

Infection
autoimmune reactions to vaccines
genetics plays a big role in this

116
Q

What is a synapse?

A

The point where neurons connect and communicate with eachother

117
Q

What is another name for an electrical synapse?

A

Gap junction

118
Q

what are connexons made from?

A

6 Connexin proteins that fit together to form a tube

119
Q

How do connexons work?

A

2 connexons, one on each cell line up to each other and create a pathway for small molecules to pass through

120
Q

What is the most common ion that moves through gap junctions?

A

Na+

121
Q

What is a very fast way of sending an action potential from one cell to another?

A

Electrical synapses though gap junctions.
This cuts out the time of a chemical synapse where the ligand has to bind and cause confirmation change etc.

122
Q

Unlike a chemical synapse, an electrical synapse can send action potentials

A

both directions.

123
Q

What causes a lot of abnormal reentry problems in the heart?

A

Electrical synapses (gap junctions) sending action potentials in both directions.

124
Q

The ______ the ion the _____ it moves through a gap junction

A

smaller; faster

125
Q

What is one determinant of how easy an action potential is going to get from one cell to another?

A

how many gap junctions are available

126
Q

Is there a lot of gap junctions in the pacing areas of the heart?

A

no, it’s mostly chemical synapses which allows for a built in delay.

127
Q

some smooth muscle has some gap junctions that allow

A

neighboring smooth muscle cells to act as a unit

128
Q

The target to a neuron and the neurotransmitter defines

A

what a cell is going to be able to do

129
Q

In the heart, ACh is

A

inhibitory

130
Q

in skeletal muscle, ACh is

A

excitatory

131
Q

What is the presynaptic terminal?

A

The sending cell

132
Q

What is the postsynaptic terminal?

A

The receiving cell