Nervous system Flashcards
1
Q
What is the main function of the nervous system
A
communication
2
Q
What 3 things does the communication of the nervous system involve
A
- Collecting information 2. Processing/evaluating information 3. Initiating responses to information
3
Q
What are the 2 major structural divisions of the nervous system
A
- Central Nervous system 2. Peripheral Nervous system
4
Q
What 2 things is the central nervous system composed of
A
- Brain 2. Spinal cord
5
Q
What 2 things is the peripheral nervous system composed of
A
- Nerves 2. Ganglia
6
Q
What 2 types of nerves are found in the peripheral nervous system
A
- Cranial 2. Spinal
7
Q
How many cranial nerves are there
A
12 pairs
8
Q
How many spinal nerves are there
A
31 pairs
9
Q
What are the 2 major functional divisions of the nervous system
A
- Sensory 2. Motor
10
Q
Sensory
A
input
11
Q
Motor
A
output
12
Q
What 2 divisions make up the sensory nervous system
A
- Visceral Sensory 2. Somatic Sensory
13
Q
Visceral Sensory
A
Input not consciously aware of
14
Q
Somatic Input
A
Input we are generally more aware of
15
Q
What are the 2 division of the motor nervous system
A
- Somatic Motor 2. Autonomic Motor
16
Q
Somatic Motor
A
Controls skeletal muscle
17
Q
Autonomic motor
A
Controls glands, cardiac muscle, and smooth muscle
18
Q
What are the 2 divisions of the autonomic motor system
A
- Sympathetic (fight or flight) 2. Parasympathetic (Rest and Digest)
19
Q
What are the 2 major cell types of nervous tissue
A
- Neurons 2. Neuroglia
20
Q
Neurons
A
Excitable amitotic cells that initiate and transmit signals
21
Q
Do neurons divide
A
no
22
Q
neuroglia
A
non-excitable mitotic cells that support/protect neurons
23
Q
Neuroglia are also known as
A
aka glial cells
24
Q
What 4 types of neuroglia are found in the CNS
A
- Astrocytes 2. Microglia 3. Ependymal cells 4. Oligodendrocytes
25
What 2 types of neuroglia are found in the PNS
1. Schwann cells 2. Satellite cells
26
Astrocytes help to form the
Blood-Brain barrier
27
Astrocytes anchor
neurons to capillaries
28
Astrocytes regulate
interstitial fluid composition
29
Astrocytes assist
neuronal development
30
Ependymal cells line cavities of
brain and spinal cord
31
Ependymal cells produce and circulate
cerebrospinal fluid
32
Ependymal cells regulate
nutrient waste exchange
33
Microglia replicate in
response to infection
34
Microglia engulf
infectious agents and remove debris
35
Oligodendrocytes wrap around and insulate
axons within the CNS to form myelin
36
Satellite cells arrange themselves
around cell body
37
Satellite cells regulate
nutrient-waste exchange
38
Schwann cells wrap around and insulate
axons of PNS to form a myelin sheath
39
What is the process of wrapping an axon with myelin
Myelination
40
What is the substance produced by glial cells that contains mostly lipids
Myelin
41
What is the function of myelin
Increases impulse transmission speed
42
What is impulse speed based on
presence or absence of myelin and thickness of axon
43
Signals move fastest along
thick myelinated axon
44
What are the 3 structural classifications of
neurons
1. Unipolar neurons 2. Bipolar neurons 3. Multipolar neurons
45
Unipolar neurons have ______ process extending from the cell body/soma
1
46
Most sensory neurons are
unipolar neurons
47
Bipolar neurons have _____ processes extending from cell body/soma
2
48
What type of neurons are found in special sense organs
bipolar neurons
49
Multipolar neurons have _____ processes extending from cell body/soma
3+
50
All motor neurons and most interneurons are
Multipolar neurons
51
What is the most common type of neuron
Multipolar neurons
52
What are the 3 functional classifications of neurons
1. Sensory neurons 2. Motor neurons 3. Interneurons
53
What is the most abundant type of functional neuron
Interneurons
54
Sensory neurons transmit impulses
Toward CNS
55
Motor neurons transmit impulses
Away from CNS
56
Interneurons
Receive, process, and store information (decide how the body responds to stimuli)
57
Neuron
Individual cells
58
Nerve
bundle of axons
59
What are the 3 functional divisions of nerves
1. Sensory 2. Motor 3. Mixed
60
What are the 2 structural divisions of nerves
1. cranial nerves 2. spinal nerves
61
Sensory nerves contain only
sensory axons
62
Motor nerves contain only
motor axons
63
Mixed nerves contain
sensory and motor axons
64
Synapse
A functional connection between two cells
65
What are the 2 types of synapses in the nervous system
1. Electrical synapse 2. Chemical synapse
66
What is the less common type of synapse
Electrical synapse
67
Electrical synapse the signal
"hops" from cell to cell
68
Chemical synapse involve the
release and binding of neurotransmitters
69
What are the 3 components of a chemical synapse
1. Presynaptic neuron 2. Postsynaptic neuron 3. Synaptic cleft
70
Presynaptic neuron
Releases neurotransmitters
71
Postsynaptic neuron
binds neurotransmitters
72
Synaptic cleft
Narrow fluid-filled gap between presynaptic and postsynaptic cells
73
Where are sodium potassium pumps found on a neuron
everywhere
74
What do sodium potassium pumps do
help establish resting membrane potential
75
Where are leak channels found on a neuron
everywhere
76
What do lead channels do
allow passive movement of ions
77
Where are chemically-gated channels found on a neuron
Receptive segment
78
What do chemically gated channels do
open in response to neurotransmitter binding
79
Where are voltage-gated channels found
axon and axon hillock
80
What do voltage-gated channels do
open in response to changes in electrical charge across the PM
81
When a neuron is at rest the chemically-gated channels are
closed
82
When a neuron is at rest the voltage-gated channels are
closed
83
In resting neurons ions are _______ distributed across the PM due to actions of pumps
unevenly
84
When neurons are at rest the cytosol/ intracellular fluid has a higher concentration of ______
K+/potassium
85
When neurons are at rest the interstitial fluid (outside the cell) has a higher concentration of ______
Na+/sodium
86
When neurons are at rest their membrane is
polarized
87
When neurons are at rest the cytosol is relatively ______ compared to the IF
negative
88
The resting membrane potential of neurons at rest is
-70
89
What opens the chemically-gated channels on neurons at rest
The binding of neurotransmitters
90
After neurotransmitters bind to the chemically gated ion channels ions
diffuse across the membrane changing its voltage
91
The voltage change of a resting neurons membrane generates a
graded potential in the postsynaptic neuron (postsynaptic potential)
92
Graded potential are ______ distance potentials
short
93
What causes graded potentials
movement of a small number of ions across PM
94
What determine the direction of a potential
what type of ion channels open
95
If Na+ channels open Na+ moves
into the cell and the inside becomes more positive
96
It is more likely that an action potential will occur when ______ ion channels open
Na+
97
If Cl- or K+ channels open Cl- moves ____ K+ moves _____
Cl- moves in and K+ moves out which causes the inside to become more negative
98
If the inside of the cell is less negative than -70 mV the cell is
depolarized
99
If the inside of the cell is more negative than -70 mV the cell is
hyper-polarized
100
What is the threshold stimulus of a neuron
-55
101
All or none law
Only if there are enough excitatory graded postsynaptic potentials and the threshold stimulus is met will an action potential be created
102
Action potential
temporary reversal in polarity exhibited by a neuron
103
What are action potentials also known as
A nerve impulse or nerve signal
104
Action potentials include what 2 things
1. Depolarization 2. Repolarization
105
Depolarization
opening of voltage-gated Na+ channels along axon
106
Depolarization causes Na+ to move
into the cell
107
Repolarization
return to resting state due to opening of voltage-gated K+ channels
108
Repolarization causes k+ to move _______ followed by the action of ______
K+ to move out followed by the action of Na+/K+ pumps
109
Neuroglia in the CNS are found in
Brain and spinal cord tissue
110
Neuroglia in the PNS are found within
cranial and spinal nerve tissue
