Exam 4 Flashcards
(196 cards)
1
Q
what is a twitch?
A
a single cycle
2
Q
what is a latent period?
A
delay between muscle action potential and beginning of muscle tension
-time required for Ca2+ release and binding to troponin
3
Q
what is rigor mortis?
A
no ATP being produced
then you decompose
4
Q
what is a single twitch?
A
muscle relaxes between stimuli
5
Q
what is summation?
A
interval between action potential is shortened and muscle cannon fully relax
-produces more forceful contractions
6
Q
what is tetanus?
A
state of maximal contraction
complete or incomplete
7
Q
how much ATP is stored in muscle?
A
only a little bit
8
Q
what does the muscle use for back up energy?
A
phosphocreatine (PCr)
9
Q
how long is anaerobic glycolysis?
A
short term
10
Q
how long is aerobic metabolism?
A
long term
11
Q
what is muscle fatigue?
A
muscle no longer able to generate/sustain expected power
12
Q
when can muscle fatigue occur?
A
at each step of muscle contraction
13
Q
how is movement orchestrated?
A
by the CNS through control of motor unit
14
Q
what is a motor unit?
A
single motor neuron and all of the muscle fibers it controls
15
Q
what are isotonic contractions?
A
creates force and moves a load
16
Q
what are isometric contractions?
A
creates force without moving a load
-carrying groceries
17
Q
what are concentric contractions doing?
A
shortening
18
Q
what are eccentric actions doing?
A
lengthening
19
Q
how do isometric contractions occur?
A
due to series elastic element
-sarcomeres still contract and create tension
20
Q
what does contraction speed depend on?
A
muscle fiber type
load
21
Q
when will contractions be fastest?
A
type 2B fiber
22
Q
what are the different classifications of neural reflexes for the efferent divisions?
A
somatic
autonomic
23
Q
what are the different classifications of neural reflexes for the CNS where information is processes?
A
spinal
cranial
24
Q
what are the different classifications of neural reflexes at the time reflexes develop in life?
A
innate
learned
25
what are the different classifications of neural reflexes for the number of neurons in loop?
monosynaptic
| polysynaptic
26
what is the input signal for a skeletal muscle reflex?
proprioceptor
27
what does the CNS determine for a skeletal muscle reflex?
determines if muscle should contract or relax
28
what is the output signal for a skeletal muscle reflex?
based on CNS decision
29
what does a somatic motor neuron do?
only contraction
30
do inhibitory neurons synapse on skeletal muscle?
no
31
where can you inhibit a contraction?
integrating center
32
what are the three types of proprioceptors?
muscle spindle
golgi tendon organ
joint receptors
33
what does the muscle spindle do?
detects muscle length
34
what does the goldi tendon organ do?
detects muscle tension
35
what does the joint receptors do?
detects changes in bone position
36
what do stretch receptor do?
signal brain about muscle length
37
what are stretch receptors made of?
specialized muscle fibers in a fusiform configuration intrafusal fibers
38
what is fusiform?
feather shaped
39
what are extrafusal fibers?
normal contractile muscle fibers
| -alpha motor neurons
40
what does the muscle spindle do as they are being stretched?
send action potentials
41
what is muscle tone?
tonic activity
42
what happens when there is a stretch reflex?
- input signal is sent to CNS
| - output signal is sent to muscle - contraction occurs
43
what does the stretch reflex prevent?
overstretching
44
how do you change the signal for muscle length?
change frequency for signal
45
how do you get an output signal?
action potential though somatic motor neuron (alpha or gamma)
46
where does the sensory neuron travel to?
integrating center
47
what does alpha-gamma coactivation do?
keeps the spindle stretched when muscle contracts
| -decreases in length
48
what is the Golgi tendon organ?
junction of muscle fibers and tendons
49
what does a junction of muscle fibers and tendons contain?
free nerve endings woven between collagen fibers
50
what does afferent input from the Golgi tendons do?
excites inhibitory interneurons
51
what do inhibitory interneurons do?
trigger a reflex to reduce/end muscle contractions
| -stop signals from CNS going to skeletal muscle
52
where are joint receptors found?
in joint capsules and ligaments around joints
53
what do joint receptors respond to?
joint movement velocity
joint position
inflammation and pain
54
what are the three different types of movement?
reflex
voluntary
rhythmic
55
what is a reflex movement?
- least complex
- mainly in spinal cord
ex: knee jerk, cough
56
what is a voluntary movement?
- most complex
- mainly in cerebral cortex
ex: playing piano
57
what is a rhythmic movement?
- intermediately complex
- in spinal cord and cerebral cortex
ex: walking
58
what is special about rhythmic movement?
they have no stimulus, sensor, or input signal
59
what do rhythmic movements have?
central pattern generations (CPGs)
60
what factors influence movement?
how complex the movement is
- number of spinal cord segments needed
- use of upper or lower motor neurons
- section of CNS controlling movement
61
what are the different spinal cord segments?
segmental
| intersegmental
62
what is the segmental part of the spinal cord?
reflex only passes through spinal portion of the spinal cord
ex: knee jerk
63
what is the intersegmental part of the spinal cord?
reflex passes through many segments of the spinal cord or brain
ex: most movement, voluntary, rhythmic
64
what is a lower motor neuron?
alpha motor neuron
| -cell body in CNS and axon synapses on skeletal muscle fibers
65
what are upper motor neurons?
lie entirely within the CNS
- control lower motor neurons
- -if they are going to the brain
66
what is white matter?
myelinated axon
67
what is myelinated axon?
bundles of axons known as tracts
68
what is ascending tract?
carry sensory info to brain
69
what is a descending tract?
carry efferent signals from brain to spinal cord
70
what does simple motor control come from?
spinal cord
71
what are the two divisions of the ventral horns of the spinal cord?
medial
| lateral
72
what does the medial tract do?
controls axial and proximal muscles
73
what does the medial tract include?
tectospinal tract
vestibular tract
reticulospinal tract
74
what is the tectospinal tract?
head orientation to environmental stimuli
75
what is the vestibular tract?
muscle control against gravity
76
what is the reticulospinal tract?
controls muscle tone in axial and proximal muscles
77
where do tectospinal tract, vestibular tract, and reticulospinal tract originate?
in mesencephalon, pons, and medulla
78
what does the lateral tract do?
controls distal muscles
79
what does the lateral tract include?
rubrospinal tract
80
what does the rubrospinal tract do?
voluntary muscle control
| implicated in control of skilled, repetitive movement
81
where is the mesensephalon?
midbrain
82
what does the corticospinal tract do?
controls the most skilled voluntary muscle movements
83
what does the corticospinal tract connect?
it connects motor cortex in parietal lobe of the brain with lower motor neurons
84
where does the corticospinal tract cross?
at pyrimdal decussation
85
what are the five tracts that control movement?
```
rubrospinal tract
corticospinal tract x 2
tectospinal tract
vestibular tract
reticulospinal tract
```
86
what are the basics of smooth muscle anatomy?
```
no striations
uninucleated
small
spindle shaped
no motor end plate
```
87
what five things come with smooth muscle anatomy?
1. more variety
2. anatomy makes research difficult
3. contrations controlled by hormones, paracrines, and NTs
4. variable electric properties
5. lots of pathways influence contraction and relaxation
88
what are the two types of smooth muscle tissue?
single unit
| multi unit
89
what does single unit muscle tissue do?
forms walls of internal organs
90
in single unit smooth muscle tissue, how are cells joined?
gap junctions
91
what do single unit smooth muscle tissues contain?
internal pace makers
92
do multi unit smooth muscle tissues have gap junctions?
no
93
do multi unit smooth muscle tissues have internal pace makers?
no
94
where are multi unit smooth muscle tissues found?
in iris and ciliary muscle
male repro tract
uterus
95
why is the uterus special?
large muscle contractions
96
what are the parts of the contractile element structure?
actin
myosin
sarcoplasmic reticulum
97
what are the characteristics of actin for contractile element structure?
longer
high ratio A:M ratio
filaments are crosshatched
98
what are the characteristics of myosin for contractile element structure?
longer
| myosin light chain
99
what is a myosin light chain?
regulatory protein chain in myosin head
100
how are contractile element structure arranged?
diagonal bundles
| -fibers become globular when contracted
101
what are the characteristics of sarcoplasmic reticulum for contractile element structure?
less overall than skeletal
IP3 - receptor channel - no T-tubules
most Ca2+ comes from extracellular space
102
what are the characteristics of dense bodies for contractile element structure?
the z-lines in smooth muscle
| where actin attaches
103
what are some characteristics of contractions for contractile element structure?
very slow contractions
104
how long is the latent period for contractions for contractile element structure?
about 200 milliseconds
105
what is tetanus?
muscles not relaxing
| sustained contractions
106
what is a twitch?
one muscle contraction
107
what is depolarization caused by?
Ca2+ entry
108
when are membrane potentials unstable?
slow wave
| pacemaker
109
how much do resting potentials vary?
-40 to -80mV
110
what are slow wave potentials?
cyclic depolarization and repolarization
111
what are pacemaker potentials?
cyclic but always reaches threshold and fire AP
112
what is the definition of a contraction?
AP or GP or no change in membrane potential
113
what controls E-C coupling?
calcium
114
where does the calcium come from for E-C coupling of smooth muscle?
extracellular space
| little from SR
115
is there any troponin or tropomyosin function for E-C coupling for smooth muscle?
no
116
what two enzymes for E-C coupling for smooth muscle rely on?
myosin light chain kinase
| myosin light chain phosphatase
117
what does myosin light chain kinase do?
attaches P to myosin to start contraction
118
what does myosin light chain phosphatase do?
removes P from myosin to stop contraction and begin relaxation
119
tension development is...
all or none
120
what does tension development depend on?
amount of calcium influx
121
in tension development, what happens when there is more calcium activity?
more light chain kinase
| stronger contractions occur
122
what are the four different types of activating stimuli for smooth muscle?
nervous
stretch
hormonal
internal pacemaker
123
what is the nervous activating stimuli for smooth muscle like?
similar to skeletal
| but no direct synapse
124
what is the stretch activating stimuli for smooth muscle like?
mechanically gated Ca2+ channels
125
what kind of contractions do stretch activating stimuli for smooth muscle have?
myogenic contraction
126
what is the hormonal activating stimuli for smooth muscle like?
ligand gated Ca2+ channels
127
what is the internal pacemaker activating stimuli for smooth muscle responsible for?
rhythmic contractions of GI tract
128
what is the basic anatomy for cardiac muscle?
```
striated with sarcomeres
unincleated
branched
intercalated disc
regulatory proteins
intermediate contraction speed
```
129
what are some differences that cardiac muscle has from skeletal muscle?
- t-tubules are larger with more branches
- SR is smaller
- mitochondria is 1/3 total cell volume
- nervous control comes from ANS and autorhythmic cells
130
what is myocardium?
bulk of the heart
| - the muscle
131
what do autorhythmic cells do?
create signals for heart contractions
| -pacemakers
132
where does the vena cava get blood from?
the body
133
where do pulmonary veins get blood from?
lungs
134
what does the right ventricle do?
pumps blood to lungs
135
what does the left ventricle do?
pumps blood to body and coronary arteries
136
why is there fibrous contractive tissue between the atria and ventricles?
structural support
| electrical insulation
137
what is valve closure caused by?
blood back pressure
138
what does chordae tendinae do?
works together with papillary muscles to prevent valve erosion
139
what is a valvular heart murmur?
leaky/narrow valve
| systolic and diastolic
140
what is a nonvalvular heart murmur?
PDA
141
what kind of tissue is cardiac muscle?
excitable
142
what are the two types of cells in cardiac muscle?
myocardial contractile cells
| myocardial autorhythmic cells
143
how can you prevent tetanus in the heart?
AP longer in cardiac contractile cells
144
why is it important to prevent tetanus in the heart?
needs to be beating constantly
| -must fill ventricles with blood
145
what can myocardial autorhythmic cells create?
their own AP
146
in what two ways does the ANS control the heart?
sympathetic - increase HR
| parasympathetic - decrease HR
147
what is tachycardia?
increase HR
148
what is bradycardia?
decrease HR
149
what is the pathway for electrical conduction through the heart?
1. SA node
2. internodal
3. AV node
4. pathways of Bundle of His
5. Bundle Branches
150
how do ventricular myocardium contract?
from apex to base
151
why is there a time delay at the AV node?
let atria finish contracting
152
for cardiac EC coupling what do t-tubules have?
voltage gated Ca2+ channels
153
for cardiac EC coupling what is RyR operated by?
Ca2+ binding
154
what initiates cardiac EC coupling?
AP
| - originated in pacemaker cells
155
what is cardiac EC coupling similar to?
skeletal muscle EC coupling
156
what does the electrocardiogram record?
electrical activity of the heart
| -cardiac cycle
157
what is the P wave?
atrial depolarization
158
what is the QRS complex?
ventricular depolarization
| -atrial repolarization
159
what is the T wave?
ventricular repolarization
160
what does the cardiac cycle consist of?
systole
| diastole
161
what is systole?
contraction
162
what is diastole?
relaxation
163
what is the PR interval?
delay of AV node allowing for filling of ventricles
164
what is the ST segment?
beginning of ventricle repolarization
165
what is end systolic volume?
mL remaining in ventricles
| -ventricles do not empty completely during systole
166
what is end diastolic volume?
volume of ventricles after diastole is large
167
what are arteries?
vessel that carries blood away from the heart
168
what does an artery become?
arterioles
169
what is a vein?
vessel that carries blood toward the heart
170
what do venules become?
veins
171
how much blood do veins carry?
50% of the blood in a body
172
what are capillaries?
thin walled vessels that connect arterioles with venules
173
what do capillaries do?
exchange nutrients and gases
174
what are the 3 basic layers of a blood vessel?
inner tunica intima
middle tunica media
outer tunica externa
175
what are the 4 types of tissue in blood vessels?
endothelium - inner
elastic connective tissue - inner
smooth muscle - middle
fibrous connective tissue - outer
176
do all veins have valves?
no
177
what do valves in veins do?
prevent backflow of blood
| -force blood toward the heart
178
where does blood flow?
down a pressure gradient
179
what happens to pressure over distance?
it decreases
180
what is flow rate?
volume of blood that passes a given point in the system per unit time (L/min)
181
what is velocity of flow?
how fast the blood flows
182
what is resistance?
tendency of the CV system to oppose blood flow
183
when does resistance increase?
when there is an increase in length and velocity
184
when does resistance decrease?
when there is an increase in radius
185
where does pressure gradient begin?
in ventricles
186
what is a pulse?
pressure wave felt as blood is pushed into the aorta
187
what happens to pressure gradient as it goes through the circulatory system?
decrease
188
when is pressure gradient the lowest?
point of ventricle filling
189
what 3 factors influence blood pressure?
volume - increase volume, increase pressure
flow rate - increase flow rate, increase pressure
resistance - influenced by vessel radius
190
what is blood flow rate influenced by?
blood velocity and CSA of vessels
191
what happens if a vessel has a wider diameter?
faster the velocity
192
how do arterioles provide resistance?
reducing vessel radius
193
what are arterioles controlled by?
metabolites
| paracrine
194
what are metabolites?
O2, CO2
| -cause dilatation
195
what are paracrine?
NO, histamine, adenosine -cause dilatation
| serotonin - cause constriction
196
what does stretching of smooth muscle cause?
constriction
| -remyogenic
