Lecture Exam Three: Fundamentals of the Nervous System Flashcards
1
Q
Which area below describes the 3 functional areas of the nervous system in a logical order?
A
sensory input, integration, motor output
2
Q
To extend your arm, your […] nervous system is activated.
A
somatic
3
Q
Somatic motor is….
A
voluntary skeletal movements
4
Q
Autonomic is…
A
involuntary to smooth muscles, glands, and cardiac muscles
5
Q
Which of the following is NOT part of the peripheral nervous system?
A
spinal interneurons
**anything directly dealing with the brain and spinal cord
6
Q
Your heat beat increases rapidly and forcefully. This response is a result of your […] nervous system.
A
autonomic
7
Q
The two basic cell types in your nervous system are…
A
- neurons
2. glial
8
Q
What are the four main neuroglia that support the CNS neurons?
A
- astrocytes
- microglial cells
- ependymal cells
- oligodendrocytes
9
Q
Glial cell is the most abundant, versatile, and highly branched of glial cells?
A
astrocytes
10
Q
Where can you find astrocytes?
A
cling to neurons, synaptic endings, and capillaries
11
Q
Which type of glial cell are small, ovoid cell with thorny processes that touch and monitor neurons?
A
microglial cells
12
Q
Microglial cells […] toward […] neurons.
A
migrate; injured
13
Q
Microglial cells can transform to […].
A
phagocytize microorganisms
14
Q
Which type of glial cell line the central cavities of the brain and spinal column?
A
ependymal cells
15
Q
Which type of glial cell has processes that wrap CNS nerve fibers, forming insulating myelin sheaths?
A
oligodendrocytes
16
Q
Electrical wire is to electrical insulating tape as peripheral neurons are to …
A
Schwann cells
17
Q
Schwann cells form […] to surround neurons in the […].
A
myelin sheath; PNS
18
Q
What are the three special characteristics of neurons?
A
- extreme longevity
- amitotic (few exceptions)
- highly metabolic rate: requires continuous supply of oxygen and glucose
19
Q
Each neuron in our bodies has a life span of …
A
an average human life
20
Q
Movement of substances towards the cell body of a neuron is termed […] movement. Away from the cell body is […].
A
retrograde; anterograde
21
Q
How is herpes complex associated with the nervous system?
A
this virus and bacterial toxin damages neural tissue by using retrograde axonal transport
22
Q
What other viruses, besides herpes simplex, take advantage of the retrograde axonal transport?
A
polio, rabies, and tetanus toxin
23
Q
Myelin sheath is composed of […], whitish, […] substance.
A
myelin; protein-lipid
24
Q
Function of myelin:
A
- protect and electrically insulate axon
2. increase speed of nerve impulse transmission
25
Myelinated fibers are [...] sheaths that surround [...] axons.
segmented; long-diameter
26
Non-myelinated fibers:
do not contain sheath and are therefore slow conductors
27
The portion of an axon that communicates with its target cell is [...].
axon terminal
28
The basis for differentiation between gray and white matter in the CNS is the presence of [...] in white matter.
myelinated fibers
29
[...] are the most common structural type of neuron in humans.
multipolar
30
Which structural type of neuron is rare?
bipolar
31
Bipolar: two processes, [...].
one axon and one dendrite
32
Where can you find bipolar processes?
retina and olfactory mucosa
33
Unipolar: one [...] process, [...].
T-like process; two axons
34
Unipolar is also known as...
pseudonipolar
35
What are the two types of processes of unipolar?
1. peripheral: associated with sensory receptor
| 2. proximal: enters CNS
36
When considering the relationship between a structural classification and a functional classification of neurons, it can be said that [...].
essentially all bipolar neurons are sensory neurons
37
T/F: Neurons have a resting membrane potential?
true
**they can change rapidly
38
In electricity, like charges [...].
repel each other
39
When opposite charges are separated the system...
has potential energy
40
[...] is the flow of electrical charge (...) between two points.
current
41
Current flow is dependent on what two factors?
1. voltage
| 2. resistance
42
Voltage:
measure of potential energy generated by separated charge
43
Resistance:
hindrance to charge flow
44
Ohm's Law:
I = V/R
```
I = current (amps)
V = voltage (voltz)
R = resistance (ohms)
```
45
The greater the potential difference in charge between two points, the [...] the voltage.
greater
46
What is the voltage across a membrane called?
membrane potential
47
In a living neuron, the cell's [...] provides resistance (R) to current flow.
plasma membrane
48
What are the two main types of ion channels
1. leakage (nongated) channels
| 2. gated channels
49
Leakage (nongated channels) are always...
open
50
Gated channels which is opened/closed by...
the shape alteration of the protein
51
List the types of gated channels:
1. chemically gated
2. voltage gated
3. mechanically gated
52
A typical resting membrane potential for a nerve cell is [...] mV.
-70 mV
53
The chief contributor to the negative charge of a resting neuron's intracellular fluid is:
a high intracellular concentration of anionic proteins
54
ECF has a higher concentration of [...], balance by [...]. While the ICF has a higher concentration of [...], balanced by [...].
sodium ions; chloride ions; potassium ions; negatively charged proteins
55
The movement of potassium into an animal cell requires...
an energy source such as ATP
56
T/F: The Na/K pump has a role with the generation of a single action potential.
false
57
Suppose a cell has only potassium channels, at what membrane potential would the concentration and electrical gradients for potassium be in balance?
-90
**if Na was leaked it would change the potential to -70
**would be maintained
58
How does a nerve cell compensate for the leakage of sodium ions into the cell, and potassium ions out of the cell?
Na/K pumps
**maintain potential
59
Maintenance of the resting membrane potential is possible due to:
1. ATP expenditure of the neuron
| 2. the actions of the Na/K pump
60
Depolarization of the neuron refers to:
reduction in membrane potential
61
Hyperpolarization:
the membrane potential increases, the inside becoming more negative
62
You would expect a neuron that depolarizes to -65 mV would:
return to resting membrane potential without generating an action potential
63
Which type of potential change decays with distance?
all types...
1. graded potential
2. synaptic potential
3. generator potential
4. receptor potential
64
Graded potentials (3):
1. short-lived, localized changes
2. triggered by stimulus that opens gated ion channels
3. named according to location and function
65
Graded potentials-- The stronger the stimulus...
the more voltage changes and the farther current flows
66
Graded potentials-- Opening of gated ion channels results in ...
depolarization or sometimes hyperpolarization
67
Graded potentials-- Name the two types of potentials:
1. receptor potential (generator potential)
| 2. postsynaptic potential
68
Principle way of neurons to send signals:
action potentials
69
Action potentials only occur in...
muscle cells and axons of neurons
70
Action potentials are also referred to as...
nerve impulse within nerves
71
What gates are open within action potential?
voltage-gated channels
72
Sodium ion concentration in the cytoplasm of a neuron [...] when its voltage-gated sodium channels open.
increases
73
The point at which the all-or-none principle of action potential generation is reached is termed the [...].
threshold
74
T/F: All depolarization events produce APs.
false
75
What is needed in order for an AP to be triggered?
depolarization must reach a threshold voltage
76
At the threshold, what happens at and to the membrane(4)?
1. the membrane is depolarized by 15-20 mV
2. sodium ion permeability increases
3. sodium influx exceeds potassium efflux
4. positive feedback cycle begins
77
Neurons generally repolarizes once the membrane potential reaches approx...
+30 mV
78
Why does repolarization occur?
voltage-gated potassium channel gates open
79
Repolarization: Na+ channels are [...] and K+ channels [...].
inactivating; open
80
Repolarization-- What happens to the AP due to the closing of Na channels?
AP spike stops rising
81
Repolarization-- What happens to the potassium ions?
exits cell down its electrochemical gradient
82
A neuron under the influence of a neurotransmitter that opens K+ channels will...
be less likely to fire an action potential
83
Hyperpolarization: Some [...] remain open, and [...] channels rest.
K+ channels; Na+
84
What occurs to the membrane during hyperpolarization?
inside of membrane becomes more negative than in resting state
**slight dip in resting voltage
85
If a sodium potassium pump is applied to a neuron, the next action potential that fires will appear...
the same as normal
86
Propagation allows AP to be transmitted from origin down ....
entire axon length toward terminals
87
Sodium influx through voltage gates in one membrane area cause what events to follow?
1. local currents
2. opening of sodium voltage gates in adjacent membrane areas
3. depolarization of that area
4. depolarization is next area
88
AP is [...] so in nonmyelinated axons, each successive segment of membrane [...], then [...].
self-propagating; depolarizes; repolarizes
89
T/F AP occurs only in a forward direction.
true
90
In an organism, action potentials are propagated unidirectionally toward the axon ending because:
membranes become nonresponsive due to inactive sodium channels after action potential generation
91
In most sensory systems, an increase in stimulus intensity is signaled by:
1. more transmitter release
2. more action potentials
** not because of a larger action potential
92
During the relative refractory period (what occurs to the system):
1. the threshold is substantially elevated
| 2. exceptionally strong stimuli could trigger action potentials
93
List the two types of refractory periods:
1. absolute refractory period
| 2. relative refractory period
94
Why is it the during a refractory period, the neuron cannot trigger another AP?
voltage-gated Na channels are closed and neuron cannot respond to another stimulus
95
Absolute refractory period:
time from opening sodium channels until resetting of the channels
96
Relative refractory period (what is it):
follows absolute refractory period where
1. most sodium channels have returned to their resting state
2. some potassium channels are still open
97
The conduction of an action potential along an unmyelinated axon is faster in [...].
large diameter fibers
98
What are the two factors of conduction velocity?
1. axon diameter
| 2. degree of myelination
99
Degree of myelination holds two types of conductions:
1. continuous conduction
| 2. saltatory conduction
100
[...] only occurs in nonmyelinated axons, a [...] conduction.
continuous conduction; slow
101
[...] only occurs in myelinated axons and is about [...] times faster.
saltatory; 30
102
The location at which a neuron interacts with its target cell (either another neuron or muscle cell, etc.) is called the [...].
synapse
103
Neurotransmitters are important in functioning [...] synapses.
chemical
104
During the events involved in information transfer across a chemical synapse, which of the following steps would be directly interrupted by exposing a neuron to a calcium channel blocker?
neurotransmitter exocytosis from the presynaptic neuron
105
Certain psychosomatic drugs exert their effects by keeping the concentration of neurotransmitters elevated within the synapse. These drugs could exert their effects by:
1. inhibiting enzymes associated with the postsynaptic membrane that degrade the neurotransmitter
2. inhibiting reuptake of the neurotransmitter by astrocytes or the presynaptic terminal
106
Generally speaking, opening chloride channels in the postsynaptic membrane will result in an [...].
inhibitory postsynaptic potential (IPSP)
107
Identify the false statement (SKIP kinda).
Spatial summation occurs with action potentials
108
Which molecule could serve as a second messenger for a G-protein linked metabotropic receptor?
1. cyclic AMP
2. calcium ion
3. cyclic GMP
4. diacylglycerol
109
What occurs in the discharge zone of neuronal pool?
neurons are most likely to generate impulses
110
Spinal reflexes are an example of:
serial processing
111
Parallel processing example:
sensed smell may remind one of an odor and any associated experiences
112
What occurs in the facilitated zone of a neuronal pool?
1. neurons on periphery of pool are farther away from incoming fiber
2. usually not excited to threshold unless stimulated by another source
