Test Three Flashcards
1
Q
purpose of postsynaptic neuron
A
carries out action, direct link to effector
2
Q
receptors are capable of sensing what
A
touch, pain, temp and chemical stimuli
3
Q
what causes the depolarization of postsynaptic membrane
A
neurotransmitter
4
Q
where is the vestibular apparatus located
A
in the inner ear
5
Q
what is negative contraction
A
tension going opposite direction of where muscle is going
6
Q
efferent division is made up of
A
somatic and autonomic motor
7
Q
when is max velocity greatest
A
at lowest force
8
Q
what is irritability is neurons
A
ability to respond to stimulus and convert it to a neural impulse, respond to action
9
Q
slow twitch and action potential
A
slow for myosin to attach to actin, slow from when signal arrive to force is longer
10
Q
function of endomysium
A
surrounds individual muscle fibers
11
Q
what are cross bridges
A
myosin attaching to actin
12
Q
what is extensor
A
increase joint angles
13
Q
what are free nerve endings
A
sensitive to touch and pressure, initially strongly stimulated then becomes adapted
14
Q
after stimulation in parasympathetic division what happens to ACh
A
degraded by acetylcholinesterase
15
Q
function of external lamina
A
just below endomysium
16
Q
force generation in muscle depends on
A
types and number of motor units recruited, initial muscle length, and nature of the neural stimulation of motor units
17
Q
how does the potential membrane resets
A
with the sodium potassium pump
18
Q
what maintains resting membrane potential
A
sodium potassium pump
19
Q
anatomy of transverse tubules
A
extend from sarcolemma to sarcoplasmic reticulum
20
Q
if we arent using muscle what is happening with signal
A
muscle not producing signal for protein synthesis and reduces stimuli
21
Q
what are the fiber types of endurance athletes
A
high % of slow fibers
22
Q
what is the motor end plate
A
pocket formed around motor neuron by sarcolemma
23
Q
what does IPSP cause
A
hyperpolarization
24
Q
the somatic nervous system controls what
A
skeletal muscle
25
what is conductivity in neurons
transmission of the impulse along the axon
26
what is another way to control of the internal environment besides nervous system
endocrine system
27
what must happen first for the cascade of events for muscle contraction to occur
nerve signal
28
what are the chemical that muscle chemoreceptors are sensitive to
H+, CO2, K+
29
what is oxidative capacity
number of capillaries, mitochondria, and amount of myoglobin/ ability to perform aerobic energy production
30
what does an excitatory postsynaptic potential (EPSP) do
causes depolarization
31
why is there is negative charge in the cell and not equilibrium
due to leaky K+ channels
32
what is muscle fatigue
decrease in muscle force production, reduce ability to perform work
33
what are the two muscle action
flexors and extensors
34
somatic motor neurons of PNS function
responsible for carrying neural messages from spinal cord to skeletal muscles
35
when does the action potential occur
when a stimulus of sufficient strength depolarizes the cell
36
what is the sensory division of the PNS
afferent fibers transmit impulses from receptors to CNS
37
where is the tension applied to in muscle
tendon
38
what is the voltage is the neurons
-40 to -75 mv
39
what helps recruit fast motor units faster
training
40
what is temporal summation
summing several EPSPs from one presynaptic neuron, increase rate=increasee strength
41
EPSP increases what
neuronal permeability to sodium
42
why does withdrawal reflex occur
response to sensory input
43
what do fast fibers have a greater speed of shortening
SR releases Ca++ at a faster rate and has higher ATPase activity
44
what fiber type has the maximal force per cross sectional area
fast fibers 2a and 2x, have more cross bridges
45
what is the smallest contractile unit
sarcomere
46
where does a neurotransmitter bind to
receptor on postsynaptic membrane
47
what is isometric
muscle exerts force without changing length, pulling against immovable object
48
how much in total body weight is the skeletal muscle
40 to 50%
49
what happens when myelin sheath deteriorates
progress loss of nervous system function, fatigue, muscle weakness, poor motor control, loss of balance, mental depression
50
what is lamina
put a sleeve or covering on something like a sarcolemma
51
is fiber type the only variable to determine success in athletic event
no
52
what does central fatigue do
depletion of excitatory neurotransmitters in the motor cortex and reduces motor output to muscle
53
what is a motor unit
motor neuron and all the muscle fibers it innervates
54
if you have more damage to muscle then what happens to fore
decreases
55
how does strength training induce change in muscle
increase in muscle fiber size (hypertrophy), increase in muscle fiber number (hyperplasia)
56
what is repolarization
return to resting membrane potential
57
what are the two main characteristics of muscle fiber types
biochemical property and contractile property
58
what type of neural stimulation of motor units is needed for force regulation
frequency of stimulation (simple twitch, summation, tetanus)
59
what is spatial summation
summing from several different presynaptic neurons, different neurons acting on same tissue
60
where are pacinian corpuscles found
tissues around joints
61
what determines the resting membrane potential
permeability of plasma membrane to ions, difference in ion concentrations across membrane
62
function of sarcoplasmic reticulum
storage cites for CA++ and terminal cisternae
63
what is the neuromuscular junction
the junction between motor neuron and muscle fiber
64
where are golgi type receptors found
ligaments and around joint
65
the autonomic nervous system controls what
smooth muscle, cardiac muscle, glands
66
what is the pathway of the neural reflex with withdrawal reflex
sensory nerve sends impulse to spinal column, interneurons activate motor neurons, motor neurons control movement of muscles
67
cerebellum does what type of movement
fast
68
the autonomic motor system is made up of
sympathetic, parasympathetic and enteric
69
how does training help with recruiting type 2
helps selectively recruit type 2 and jump over type one
70
what type of motor units produce greater force
more motor units and fast motor units
71
how is it possible to gain strength with GTO
ability to voluntarily oppose GTO inhibition
72
withdrawal reflex is
the reflex contraction of skeletal muscle
73
what covers the axon
schwann cells, myelin sheath along length of axon
74
what are the fiber types in nonathletes
50% slow and 50% fast
75
where is the threshold located on the neuron
axon hillock
76
is a neuron faster or muscle twitch
neuron
77
what is multiple sclerosis
neurological disease that destroys myelin sheaths of axons
78
cell body structure
contains the nucleus
79
purpose of presynaptic neurons
can excite or inhibit post
80
what is a motor unit
motor neuron and all fibers it innervates
81
how can you improve multiple sclerosis
exercise
82
what is vestibular apparatus sensitive to
changes in linear and angular acceleration ( stimulated by head movement)
83
what are isotonic exercise
concentric and eccentric
84
what is ideal length for force regulation
where we can form the most cross bridges
85
what % higher does type 2 fibers have in max force per cross sectional area
10 to 20%
86
force production is related
to number of myosin cross bridges in strong binding state
87
function of epimysium
surrounds entire muscle
88
before action potential could travel down T tubule what must happen
Ach binding
89
what is the most ion in the extracellular fluid concentrations
Na+ and Cl-
90
what is the motor division of the PNS
efferent fibers transmit impulses from CNS to effector organs
91
what happens with fatigue and high intensity exercise
accumulation of lactate, H+, ADP, Pi, and free radicals
92
which fiber type has higher max velocity
type 2
93
function of sympathetic division
release norepinephrine to excite effector organ
94
function of motor cortex through thalamus
forwards message sent down spinal neurons for spinal tuning and onto muscle
95
functions of the skeletal muscle
force production for locomotion and breathing, force production for postural support, and heat production during cold stress
96
function of gamma motor neurons
stimulate intrafusal fibers to contract with extrafusal fibers
97
what is the sliding filament model
muscle shortening occurs due to movement of the actin filament over the myosin filament, reduces the distance between z lines of sarcomere
98
if you have a small muscle change then that leads to what type of ROM
long range of motion
99
what is the nervous system made of
central and peripheral
100
major structures of brain stem
medulla, pons, midbrain, reticular formation
101
what is sarcopenia
decrease levels of testosterone and decreasing activity that males experience
102
purpose of myelin
speed up conduction of signal and direct signal
103
function of synapse
contact points between axon of one neuron and dendrite of another neuron
104
motor cortex function
motor control and voluntary movement
105
what does an action potential do in a neuron
open Na+ channels and Na+ diffuses into cell causing it to become more positive
106
how does atrophy occur
due to prolonged bed rest, limb immobilization, reduced loading during space lift
107
are effect organs under voluntary or involuntary control
involuntary
108
what is the size priniciple
smallest motor units recruited first
109
whats the length of a contractile unit
z disc to z disc
110
what is force velocity relationship
if velocity increases then force decreases and vice versa
111
function of dendrites
conduct impulses toward cell body
112
function of cerebellum
coordinates and monitors complex movement which incorporates feedback from proprioceptors
113
speed of contraction is based on what for muscle fiber types
myosin ATPase activity
114
what are the two type of muscle action
isometric and isotonic
115
cerebellum initiates what
fast, ballistic movements
116
what is atrophy
loss of muscle mass and strength
117
what are contributing factors for muscle fatigue
high intensity exercise
| and long duration exercise
118
what is a muscle twitch
contraction as the result of a single stimulus
119
what else does the vestibular apparatus do during exercise
head and eye movement
120
characteristics of type 1 fibers
slow twitch, slow oxidative, lowest power, highest capacity, most mitochondria, high capillaries
121
what is the neuromuscular cleft
short gap between neuron and muscle fiber
122
what are proprioceptors
receptors that provide CNS with info about body position
123
joint proprioceptors have what type of receptors
free nerve endings, golgi type receptors, pacinian corpuscles
124
what is important about type of myosin ATPase
speed of ATP degradation, faster detachment and reattachment to and from actin
125
what is a neurotransmitter
chemical messenger released from presynaptic membrane
126
what is maximal force production
force per unit of cross sectional area
127
what is the all or none law
once a nerve impulse is initiated, it will travel the length of the neuron but has to reach threshold
128
what fibers do we gain during muscle loss from age
slow fibers
129
what is the central governor theory
central control center regulates exercise performance and reduces motor output to exercising muscle
130
what are the fiber types in power athletes
high % in fast fibers
131
what initial muscle length is good for force generation
ideal length and increased cross bridge formation
132
what happens when Ach is released from motor neuron
causes and end-plate potential
133
after stimulation with sympathetic division, what happens to NE
removed from synapse or inactivated
134
what is repolarization in neurons
K+ leaves cell rapidly, Na+ channel close
135
whats the difference between endocrine and nervous system
fast response control system for nervous and hormonal is long enduring fine tuning system (slow)
136
what causes damage in muscle
myosin heads are being pulled and stretched but not detaching
137
how does endurance training induce change in muscle
increase in oxidative capacity
138
muscle spindle consists of
intrafusal fibers and gamma motor neurons
139
what allows for fine tuning of motor program
feedback from muscle receptors and proprioceptors
140
muscle chemoreceptors are sensitive to
changes in the chemical environment surrounding the muscle
141
what does central fatigue affect
higher brain centers and motor neurons
142
structure of gray matter
no myelin to allow nerve signal to go everywhere
143
control of motor function happens with
subcortical and cortical motivation areas, cerebellum and basal ganglia, motor cortex through thalamus
144
what can help improve strength and endurance for age related change in skeletal muscle
regular exercise
145
what does the cerebellum and basal ganglia do with control of motor function
covert rough draft into movement plan
146
afferent division is made up of
somatic (musculature), visceral (organs) and special sensory (chemo and baroreceptors)
147
brain stem responsible for
metabolic functions, cardiorespiratory control, complex reflexes
148
how long is initial atrophy and why
2 days bc decreased protein synthesis
149
muscle spindle responds to
changes in muscle length (stretch of muscle) and wants to contract muscle
150
how does GTO work
stimulation results in reflex relaxation of muscle and inhibitory neurons send IPSPs to muscle fibers
151
whats included in a sarcomere
Z line, M line, H zone, A band, and I band
152
what is kinesthesia
conscious recognition of the position of body parts and limb movement rates
153
what is the recruitment pattern during incremental exercise
type s, type FR (2a), type FF (2x)
154
what is a depolarization
electrical signal that causes a chemical release that causes a mechanical event
155
intrafusal fibers run what to normal muscle fibers
parallel
156
what is the cross extensor reflex
opposite limb supports body during withdrawal of injured limb, activates antagonist on opposite limb
157
why are the smaller motor units recruited first
produce larger EPSP and result in action potential sooner bc they have smaller thresholds
158
what is innervation ratio
number of muscle fibers one neuron innervates
159
what is the innervation ratio
number of muscle fibers per motor unit, low number of fibers= fine motor control, high number of fibers= less fine motor control
160
what is a power stroke
formation of cross-bridges between actin and myosin filaments
161
if there is more muscle how much force
more force can be generated
162
during hyperpolarization, what is the voltage in the cell
-110 mv
163
goal of summation is
help make sure event actually occurs
164
what happens during excitation contraction coupling
action potential travels down t tubules and causes release of Ca++ from SR, Ca++ binds to troponin and causes position change of tropomyosin exposing active site of actin, strong binding state formed between actin and myosin and contraction occurs.
165
what gate is closed during IPSP
close sodium gates
166
how much muscle mass is lost between 25 and 50
10%
167
central governor theory protects against
catastrophic disruptions to homeostasis
168
in a velocity of movement, the power generated is greater in a muscle with a higher percent in
fast twitch fibers
169
basal ganglia does what type of movement
slow, deliberate
170
what is another name for myosin
thick filament
171
what does the subcortical and cortical motivation areas do
send a rough draft of the movement
172
if you want more precision with muscle
less muscle fibers per one neuron
173
at older age what fiber type are we losing
type 2
174
what are the contractile properties of muscle fiber types
maximal force production, speed of contraction and muscle fiber efficiency
175
what is the ratio of force and time
force increase when time decreases
176
how many heads are on one myosin
6
177
what is required for muscle contraction, energy wise
myosin ATPase breaks down ATP as fiber contracts
178
how does further atrophy occur
reduced protein synthesis
179
what is spinal tuning
voluntary movement translated into appropriate muscle action
180
what is the function of the general nervous system
control of the internal environment, voluntary control of movement, programming spinal cord reflexes, assimilation of experiences necessary for memory and learning
181
where is Ach released from
motor neuron
182
what concentric
muscle shortens during force production
183
is the withdrawal reflex of the skeletal muscle dependent on higher brain centers
no so the rate of response can be fast
184
what are the biochemical properties of muscle fiber types
oxidative capacity and type of myosin ATPase
185
what is the stretch reflex
stretch on muscle causes reflex contraction
186
how much muscle mass is lost between age 50-85
40%
187
what is an end plate potential
depolarization of muscle fiber
188
cerebrum has what two cortexes
cerebral and motor
189
how does EPSP and IPSP play a role in withdrawal reflex
EPSP to muscle to withdraw from stimulus (activate) and IPSP to antagonist muscle (inhibit)
190
what is inhibitory postsynaptic potentials
move the difference of the 2 areas of membrane mover farther apart, making it more difficult to reach threshold, making harder for action to take place
191
what are contractile protein
actin and myosin
192
how many actin does one myosin act on
6
193
what is motor unit recruitment
recruitment of more muscle fibers through motor unit activation
194
purpose of parasympathetic division
release ACh that inhibits efector organ
195
when do you start to decline with skeletal muscle
40 y.o.
196
what are the muscle proprioceptors
muscle spindle and golgi tendon organ
197
what is involuntary drive
what you can contract beyond what you think you can do
198
what do myofibrils contain
contractile proteins
199
temporal and spatial summation occurs with what
EPSP
200
what makes up the PNS
neurons outside the CNS, sensory and motor division
201
what is the most ion in the intracellular fluid concentrations
K+
202
why is atrophy not permanent
can be reversed with resistance training
203
what is excitation contraction coupling
depolarization of motor end plate is coupled to muscular contraction
204
cerebellum has connection to
motor cortex, brain stem, and spinal cord
205
what does motor end plate look like
depression allowing more surface area to allow more receptors in the pocket
206
fast twitch fiber and action potential
arrival of electrical signal and then increase of force is much shorter
207
characteristics of type 2x fibers
fast twitch, fast glycolytic, highest power but lowest capacity
208
function of autonomic nervous system
responsible for maintaining internal environment
209
function of perimysium
surrounds bundles of muscle fibers (fascicles)
210
what is eccentric
muscle produces force but length decresase
211
cerebral cortex function
organization of complex movement, storage of learned experiences, reception of sensory info
212
what happens to H zone during contraction
disappears
213
where are proprioceptors located
joints and muscles
214
location of sarcolemma
muscle cell membrane
215
speed of shortening is greatest in what fiber
fast fibers
216
what is the resting membrane potential
negative charge inside cells at rest
217
function of vestibular apparatus
responsible for maintaining general equilibrium and balance (head position)
218
how many skeletal muscles are in the human body
400
219
function of golgi tendon organ
inhibit recruitment of motor units and causes relaxation
220
function of muscle proprioceptors
provide sensory feedback to nervous system from tension development by muscle and account of muscle length
221
what is the most powerful contraction you can do
isometric
222
function of axon
carriers electrical impulse away from cell body
223
what are the requirements for electrical activity in neurons
irritability and conductivity
224
what makes up the CNS
brain and spinal cord
225
a neuron fires when
a stimulus changes the permeability of the membrane allowing sodium to enter at a high rate
226
function of golgi tendon organ
monitors tension developed in muscle and prevents muscle damage during excessive force generation
227
is atrophy permanent
no
228
what happens with fatigue and long duration exercise
muscle factors due to accumulation of free radicals, electrolyte imbalance and glycogen depletion, central fatigue from reduced motor drive to muscle from CNS
229
what are the structures of a neuron
cell body, dendrites, axon and synapse
230
what is flexor
decrease joint angle
231
characteristics of type 2a fibers
intermediate fibers, fast oxidative glycolytic fibers
232
what is another name for actin
thin filament
233
what are the motor functions of the spinal cord
withdrawal reflex, other reflexes involved with voluntary movement, spinal tuning
234
what ions are involved with the resting membrane potential
Na+, K+, Cl-, and Ca++
235
muscle chemoreceptors send info to and why
CNS about metabolic rate of muscular activity which can help regulate cardiovascular and pulmonary responses
236
function of pacinian corpuscles
detect rate of joint rotation
237
what determines the amount of force produced
number of cross bridges
238
what are the sources of ATP for energy for muscle contraction
phosphocreatine, glycolysis, oxidative phosphorylation
239
what determines how much O2 uptake is utilized in muscle fiber types
number of mitochondria
240
what is the voltage in the muscle
-95 to -100 mv
