Neurology Flashcards

(74 cards)

1
Q

Astrocytes (Glial Cell)

A

Work in healing, tissue repair; regulate ion concentrations, synapse formations and more; Create a supportive framework for neurons - VERY DIVERSE!

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

Ogliodendrocytes (Glial Cell)

A

Form and maintain myelin in the CNS

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

Microglia (Glial Cell)

A

CNS macrophages; Important immune system workers of the CNS

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

Ependymal Cells (Glial Cell)

A

Create cerebral spinal fluid in the CNS

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

Schwann Cells (Glial Cell)

A

Create myelin in the PNS

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

What does amitotic mean?

A

It doesn’t divide

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

Why do neurons need a lot of glucose and have a lot of ATP?

A

They have a very high metabolic rate

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

Are neurons the most abundant cell in the CNS?

A

No, glial cells are.

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

What is the function of an afferent neuron?

A

Transmit information INTO the central nervous system from receptors at their peripheral endings

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

What is the function of an efferent neuron?

A

Transmit information OUT of the central nervous system to effector cells, particularly muscles, glands, or other neurons

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

Where are interneurons located?

A

Entirely within the CNS

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

Where is an afferent neuron located?

A

Cell body and long peripheral process of axon - PNS

Short central process of axon - CNS

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

Where is an efferent neuron located?

A

Cell body, dendrites, a small segment of the axon - CNS

Majority of the axon - PNS

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

Which neuron accounts for greater than 99 percent of all neurons?

A

Interneurons

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

If axons are severed, can they repair themselves?

A

It depends; Only if the damage occurs outside of the CNS and does not affect the neuron’s cell body

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

How quickly does axon regrowth occur?

A

Only 1 mm per day

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

What happens (at the cellular level) with a crush injury to the spinal cord?

A

Apoptosis (cell death) of the oligodendrocytes (myelin-producing cells)

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

What is the Resting Membrane Potential?

A

The difference in the charge between the outside of the cell and the inside of the cell

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

How is membrane potential established?

A

Neurons use a Na+/K+ pump to pump 3 Na+’s OUT for every 2 K+’s IN (creates a relatively negative interior)

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

What happens during depolarization?

A

Na+ channels open, Na+ comes in, and the interior cell becomes less negative

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

What happens during Summation?

A

The EPSP’s and the IPSP’s add up to a depolarization of 15mV or more, threshold potential has been reached

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

What happens at Threshold potential?

A

Sodium channels are open; signal fires

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

What are the steps of an Action Potential?

A
  1. Resting Membrane Potential
  2. Threshold Reached
  3. Depolarization - Na+ fly into cell
  4. Na+ channels close (signal can’t go backwards), slower K+ channels open
  5. Membrane Repolarizes
  6. Hyperpolarization (makes it even more difficult for signal to transmit backwards)
  7. K+ channels close, Na+ channels are reactivated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do Lidocaine, Procaine, and Marcaine inhibit an action potential?

A

By blocking the voltage-gated Na+ channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the absolute refractory period?
When the plasma membrane cannot respond to another stimulus (another action potential cannot be sent at this time)
26
What is the relative refractory period?
When another action potential can be sent ONLY if it's strong enough to overcome hyperpolarization AND the normal amount of depolarization
27
Where do action potentials occur?
The nodes of Ranvier
28
What is saltatory conduction?
- When myelin acts as an insulator that allows ions to flow between segments rather than along the entire length of the membrane - This results in increased velocity of neuronal conduction
29
What are three benefits of myelin?
1. Add speed 2. Reduce metabolic cost 3. Save room in the nervous system because axons can be thinner
30
What are synapses?
When nerves reach out and almost touch each other
31
How can synapses pass information?
1. Chemically | 2. Electrically
32
Can synapses be excitatory and inhibitory?
Yes (depends on what neurotransmitter is being used)
33
What happens during an electrical synapse?
Pre and post synaptic cells are connected via gap junctions
34
What happens during a chemical synapse?
- Pre-synaptic neurons release neurotransmitters from their axon terminals - Neurotransmitter binds to receptors on post-synaptic neurons
35
Where are neurotransmitters produced and stored?
In the vesicles of the axon terminal
36
What steps occur during docking of the vesicles and release of neurotransmitters?
1. Action potential reaches terminal 2. Voltage-gated calcium channels open 3. Calcium enters axon terminal 4. Neurotransmitter is released and diffuses into the cleft 5. Neurotransmitter binds to post-synaptic receptors 6. Neurotransmitter is removed from synaptic cleft
37
What makes it possible for the vesicles to bind to the plasma membrane?
SNARE proteins
38
How is the neurotransmitter released?
Through exocytosis
39
What is the function of autoreceptors?
- Neurotransmitters will bind to autoreceptors and turn off further release from pre-synaptic cell - Build-in break system - Negative feedback! - Autocrine cell signaling
40
How are Neurotransmitters removed from the synapse?
1. Diffusion of the transmitter from the cleft 2. Degredation of the transmitter by enzymes 3. Reuptake into the pre-synaptic cells for reuse 4. Removal of the receptors in the post-synaptic cell's membrane
41
Which neurotransmitter is ALWAYS the first signaler on efferent pathways to the peripheral nervous system?
Acetylcholine
42
What enzyme is responsible for breaking down Acetylcholine into AcCoA and Choline?
Acetylcholinesterase (AChE)
43
Which neurotransmitters are made from the amino acid tyrosine?
1. Dopamine 2. Epinephrine 3. Norepinephrine
44
Which neurotransmitters are important in the Sympathetic Nervous System?
Norepinephrine and Epinephrine
45
If dopamine, epinephrine, and norepinephrine aren't taken back up into the pre-synaptic neuron, how are they destroyed?
By monoamine oxidase (MAO)
46
Which neurotransmitter is made from the amino acid Tryptophan?
Serotonin
47
This neurotransmitter acts more like a modulator than a true transmitter.
Serotonin
48
Serotonin excites what pathway?
Muscle
49
Serotonin inhibits what pathway?
Sensory
50
What are Endogenous Opioids?
Short polypeptides (15 to 25 amino acids long)
51
How are Endogenous Opioids different from other transmitters?
Made in the cell body, put into vesicles, and transported all the way down the axon for release
52
How are Endogenous Opioids broken down?
Peptidases
53
"Runner's High" has been attributed to what neurotransmitter?
Endogenous Opioid
54
What do Endogenous Opioids have an effect on?
Appetite, mood, and emotion
55
How does Clostridium tetani affect synaptic mechanisms?
Prevents vesicle fusion with the membrane, inhibiting release of GABA– a neurotransmitter that would normally inhibit muscle contraction
56
How does Clostridium botulinum affect synaptic mechanisms?
Interferes with actions of SNARE proteins at excitatory synapses that activate muscles
57
What does the Forebrain contain?
Cerebrum and Diencephalon (thalamus, hypothalamus, epithalamus)
58
Subcortical nuclei are interneurons that...
1. Bring information into the cerebrum 2. Carry information out 3. Connect different areas within a a hemisphere
59
Each hemisphere of the brain contains...
1. Cerebral cortex (outer shell of gray matter composed mostly of cell bodies that give the area a gray appearance) 2. Inner layer of white matter (area that contains myelin)
60
What is the corpus callosum?
A massive bundle of nerve fibers that connects the cortex layers of the right and left hemispheres
61
Why is the cortex highly folded?
To increase surface area - increasing volume of the brain (4 times larger)
62
What are the four lobes of the brain?
1. Frontal 2. Parietal 3. Temporal 4. Occipital
63
What are the functions of the frontal lobe?
Reasoning*, planning*, parts of speech, movement*, emotions, and problem solving
64
What are the functions of the parietal lobe?
Movement*, orientation, recognition, perception of stimuli*
65
What is the function of the occipital lobe?
Visual processing
66
What are the functions of the temporal lobe?
Perception and recognition of auditory stimuli*, memory*, and speech
67
What are upper motor neurons?
The brain's neurons that direct voluntary movements and integrate signals to create many involuntary muscle activities
68
What are lower motor neurons?
Neurons that go to a muscle | cell body is in the spinal cord, axon is in the periphery
69
What is the function of basal ganglia?
Control movement and posture; complex aspects of behavior
70
What are the functions of the cerebral cortex?
- *Integration* - Collecting afferent information and processing it - Effects motor and endocrine systems based on that info
71
What is the function of the thalamus?
Arousal and focusing attention
72
What is the function of the hypothalamus?
- Master commander for neural-endocrine coordination | - Eating, drinking, reproduction
73
What is the function of the epithalamus?
Regulate biological rhythms
74
What is the limbic system?
A “coalition” of forebrain areas (parts of cerebrum, thalamus, and hypothal) which coordinates emotional centers and and endocrine signals