Chapter 3 Flashcards
1
Q
What 2 things compose the central nervous system?
A
- Brain
- Spinal cord
2
Q
What is the term referred to as neurons responding to stimuli and converting those messages to an electrical signal?
A
Nerve impulse
3
Q
What is the basic structural unit of the nervous system?
A
Neuron
4
Q
The neuron has ______ major regions.
A
3
5
Q
What are the 3 major
A
6
Q
What are the roles of the cell body?
A
- Contains nucleus
- Cell processes radiate out
7
Q
What are the roles of dendrites?
A
- Recever cell processes
- Carry impulse toward cell body
8
Q
What are the jobs of the axon?
A
- Sender cell process
- Starts at axon hillock
- End branches
- Axon terminals
9
Q
Sensory is referred to as _________ signals.
A
Incoming
10
Q
Motor is referred to as ______ signals.
A
Outgoing
11
Q
Somatic is referred to as ______ to skeletal muscles
A
Voluntary
12
Q
Autonomic is referred to as _______ to viscera.
A
Involuntary
13
Q
What are the 3 MUST’s for the electrical signal between periphery and brain?
A
- Must be generated by a stimulus
- Must be propagated down an axon
- Must be transmitted to next cell in line
14
Q
T/F: Difference in electrical charges between outside and inside of the cell.
A
True
15
Q
T/F: The inside of the resting membrane potential is more negative relative to the outside.
A
True
16
Q
What is the negative charge on the inside of the cell?
A
-70mV
17
Q
What are the two causes for the inside of the cell being more negative than the outside?
A
- High Na outside cell
- Medium K+ Inside cell
18
Q
When charges across the membrane differ, the membrane is ______.
A
Polarized
19
Q
RMP is maintained in what 2 ways?
A
- Membrane more permeable to K+ due to open K+ channels
- Na+ - K+ pump (primary mechanism)
20
Q
What occurs when inside of cell becomes less negative?
A
Depolarization
21
Q
What is the term when more Na+ channels open, and Na+ enters the cell?
A
Influx
22
Q
What is required for nerve impulse to arise and travel?
A
Depolarization
23
Q
What occurs when the inside of the cell becomes more negative?
A
Hyperpolarization
24
Q
What is the term used when more K+ channels open and K+ leaves the cell?
A
Efflux
25
What makes it more difficult for nerve impulse to arise?
Hyperpolarization
26
What is Repolarization?
The return to RMP (Resting Membrane Potential) (-70mV)
27
In what 2 ways does depolarization and Hyperpolarization contribute to the nervous system function? (G, C)
- Graded Potentials
- Can excite or inhibit a neuron
28
What are localized changes in membrane potential?
Graded potentials (GPs)
29
How are Graded Potentials (GPs) generated?
Incoming signals from dendrites
30
How do GPs help the cell body?
Help by decking whether to pass a signal on
31
What happens during Excitatory postsynaptic potential (EPSP)?
- Na+ channels open = Na+ influx
- Depolarization
32
What happens during the inhibitory postsynaptic potential (IPSP)?
- K+ channels open = K+ efflux
- Hyperpolarization
33
Strong ________ will lead to an ____________.
EPSP ; Action potential
34
What are 4 facts along with a strong EPSP leading to an AP? (R,L,A,M)
-Rapid depolarization of neurons membrane
- Last - 1 ms
- AP will be propagated down axon & transmitted to next cell
- Must reach a threshold mV
35
If GP reaches _____ mV to _____ mV, ______ will occur
-55, -50, AP
36
What is the principle that refers to this statement:
“Threshold mV not reached, then no AP”
All-or-none principle
37
What keeps total of EPSPs & IPSPs?
Axon hillock
38
State the process/stage when given the mV:
-70 to -55mV: ____________, ________
-55 to +30mV: ____________, ________
+30 to -70mV: ____________, ________
Depolarizing GP, Na+ influx
Depolarizing AP, Na+ influx
Repolarizing AP, K+ efflux
39
What 2 characteristics determine propagation speed down an axon?
- Axon diameter
- Myelin
40
A ______ axon = a _________ propagation speed
Larger ; faster
41
The myelin’s fatty sheath around an axon is formed by what?
Schwann cells
42
Within the myelin, what are the non-continous spaces?
Nodes of ranvier
43
What speeds up propagation?
Saltatory conduction
44
What is the degeneration of myelin; loss of coordination?
Multiple sclerosis
45
For neurons to communicate, APs transfer form a _________ to _______ neuron.
Presynaptic ; postsynaptic
46
What is the site of neuron-to-neuron communication?
Synapse
47
T/F: AP must travel across synapse.
True
48
Give the pathway of transmitting AP’s.
Presynaptic axon terminal ——> synapse——> postsynaptic dendrites
49
T/F: signal changes form across synapse
True
50
T/F: the correct sequence for neuron-to-neuron communication is:
Electrical ——> chemical ——> electrical
True
51
AP can only move in _______ direction(s).
One
52
Axon terminals contain _________.
Neurotransmitters
53
What are neurotransmitters?
Chemical messengers
54
________ bind to receptor on postsynaptic surface.
Neurotransmitters
55
Neurotransmitters stimulate _______ in postsynaptic neuron.
GP’s
56
T/F: If depolarization reaches threshold, AP occurs, and the process does not continue.
False; it does continue
57
What is the site of neuron-to-muscle communication?
Neuromuscular junction
58
The neuromuscular junction uses _________ as its neurotransmitter.
Acetylcholine (ACh)
59
Postsynaptic cell in the neuromuscular junction is a what?
Muscle fiber
60
ACh binds to receptor at special site also known as the ________?
Motor end plate
61
There are _______ known or suspected neurotransmitters.
50+
62
Neurotransmitters fall into what 2 categories?
Small-molecule, rapid acting
Large-molecule (neuropeptides), slow-acting
63
ACh and norepinephrine govern ______.
Exercise
64
ACh stimulates ________, and mediates ___________ nervous system effects.
Skeletal muscle contraction ; parasympathetic
65
NE mediates ______ nervous system effects.
Sympathetic
66
The brain is divided into what 4 segments?
- Cerebrum
- Diencephalon
- Cerebellum
- Brain Stem
67
What lobe is the primary motor cortex of the brain?
Frontal love
68
The frontal lobe provides conscious control of __________ movement.
Skeletal muscle
69
Neurons in the frontal lobe are called ________.
Pyramidal cells
70
What part of the brain is where decisions are made about movement?
Frontal lobe
71
The Diencephalon contains what 2 segments of the brain?
- Thalamus
- Hypothalamus
72
What is the sensory relay center of the brain?
Thalamus
73
All sensory input enters the thalamus besides ______.
Smell
74
The thalamus regulates what sensory ______ reaches the conscious brain.
Input
75
________ determines what we are consciously aware of.
Thalamus
76
What portion of the brain maintains homeostasis?
Hypothalamus
77
The cerebellum is located where?
Behind the brain stem
78
Which portion of the brain controls rapid, complex movements?
Cerebellum
79
T/F: The thalamus coordinates timing, sequence of movements.
False; its the cerebellum
80
T/F: The cerebellum compares actual to intended movements and initiates correction.
True
81
The ________ relays information (both ways) between brain and spinal cord.
Brain stem
82
The brainstem is composed of what 3 things?
-midbrain
-pons
-medulla oblongata
83
_______ is the most common form of dementia?
Alzheimer’s
84
T/F: Tau and beta amyloid are contributions to Alzheimer’s.
True
85
Astrocyte and microglia
86
What portion of the brain is first affected by Alzheimer’s?
Hippocampus
87
_______ is continuous with medulla oblongata.
Spinal Cord
88
The spinal cord is composed of tracts of nerve fibers that permit _____________ of nerve impulses.
Two-way conduction
89
What connects the CNS to PNS?
Spinal Cord
90
The _______ connects to brain and spinal cord via ____ pairs of nerves.
43
91
Both cranial and spinal nerves directly supply _____________.
Skeletal muscle s
92
__________ transmits information from periphery to brain
Sensory division
93
What receptors are located in join capsules?
Joint kinesthetic receptors
94
Joint kinesthetic receptors are sensitive to ________ & _________.
Joint angles & rate of angle change
95
T/F: Joint Kinesthetic receptors can sense joint position and movement
True
96
Muscle spindles are sensitve to _________ & ______.
Muscle length / rate of length change
97
Golgi tendon organs are sensitive to _________ applied by muscle to its tendon.
Tension
98
T/F: Golgi tendon organs provide information about strength of contraction
True
99
The Motor division transmits information from ____ to ___.
brain ; periphery
100
Autonomic controls _____ internal functions.
Involuntary
101
What are 3 examples of exercise related autonomic regulation? (HrBpLf)
Heart rate
Blood pressure
Lung function
102
What are the 2 complementary divisions of the autonomic nervous system?
Sympathetic & parasympathetic nervous system
103
Sympathetic is also referred to as ________.
Fight or flight
104
Parasympathetic is also referred to as ______.
Rest and digest
105
Which complementary autonomic division prepares the body for exercise?
Fight or flight
106
Which complementary autonomic division is active at rest?
Rest and digest
107
_________ is the process of communication and interaction between sensory and motor systems.
Sensory-Motor Integration
108
There are ____ sequential steps in sensory motor integration.
5
109
There are ____ sequential steps in sensory motor integration.
5
110
_________ can be integrated at many points in CNS
Sensory input
111
T/F: Sensory input complexity of integration increases with ascent through CNS.
True
112
________ is the fastest mode of response.
Motor reflex
113
T/F: Motor reflex impulse travels up to the brain.
False; it ends in spinal cord
114
Reflexes are ____,______ responses to a given stimulus.
Instant
Preprogrammed
115
T/F: motor reflex occurs before conscious awareness.
True
116
Muscle Spindles are a group of ____ - ____ small, specialized ___________.
4-20; intrafusal muscle fibers
117
Muscle Spindles are innervated by _________.
Y-motor neurons
118
The _________ of the muscle spindles contains no or few actin and myosin.
Central region
119
GTO is a sensory receptor embedded in a _______.
Tendon
120
There are ___ to ____ muscle fibers attached to each GTO
5-25
121
GTO are sensitive to ________.
Tension
122
________ are important in resistance exercise.
GTO
123
When stimulated by excessive tension, GTO’s:
- I
- S
-R
Inhibit agonists
Safety mechanism that prevents excessive tension
Reduce potential for injury in resistance exercise
124
_________ neuron carries AP to muscle.
a-motor
125
T/F: During a motor response, AP spreads to muscle fibers of motor unit
True
126
What are the two types of motor control?
Fine & Gross
127
Extra-ocular muscles have a innervation ration of __:__.
1:15
128
Gastrocnemius has a innervation ratio of __:__.
1:2000
129
Gastrocnemius has a innervation ratio of __:__.
1:2000
130
Motor response is a _______ of motor units.
Homogeneity
