4/3 Muscle Movement Flashcards
1
Q
What are the muscle types?
A
striated and smooth depending on how the fibrous elements are arranged
2
Q
What are striated muscles?
A
Striped. Fibrous element arrangement in well organized rows and columns. Voluntary or involuntary.
3
Q
What are smooth muscles?
A
Fibrous elements arranged in random distribution. Involuntary for the most part
4
Q
What is the one smooth muscles that is voluntary?
A
external sphincter on the urethra on the bladder so we can control when we go to the bathroom
5
Q
Skeletal muscles is what?
A
voluntary
6
Q
Our Heart is under what control?
A
myogenic control-involuntary-heart beat is originated within the muscle tissue itself in the heart.
7
Q
Most invertebrates have a _____ heart. an what control is it under?
A
neurogenic heart and under nervous system control
8
Q
The muscles in the heart are connected physically and electrically as well. How are they connect electrically?
A
intercalated disks
9
Q
What are to other names for muscle fibers?
A
myofibers=muscle cells
10
Q
What is the sarcolemma?
A
cell membrane in a muscle cell
11
Q
what is the structural arrangement of the sarcolemma?
A
it has opening that are continuous with the cell membrane so for example if you stuck you finger really far into it and it didnt break and when you pulled your finger out the indentation you made is continuous with the outside but penetrates deep into structure.
12
Q
in muscle cells transverse tubues occur at what?
A
regular intervals
13
Q
If an action potential were to occur across the sarcolemma what happens in regards with the transverse tubular system?
A
the action potential will also sweep down the t tubular system deep into the muscle
14
Q
What is the sarcoplasmic reticulum?
A
pouchlike structure and it makes pouches on either side of the t tubular system called terminal cisternae
15
Q
What is the difference between the endoplasmic reticulum and the sarcoplasmic reticulum?
A
the ER acts as a barrier one thing happen on one side another thing happens on another side and is contiguous with the cell membrane basically its the cell membrane folded on itself multiple times. However the sarcoplasmic reticulum is separate from the sarcolemma-distinct pouch-like arrangement.
16
Q
WHat does the sarcoplasmic reticulum do?
A
Good at scouring calcium out of the sarcoplasm
17
Q
sarcolemma and sarcoplasmic reticulum+t tubule do or dont touch
A
dont
18
Q
Terminal cisternae are packed with what types of pumps? and what does this do?
A
calcium
reduce the ca level in the sarcoplasm from saturation to 10^-7 mol
19
Q
in a muscle cell in the resting state where is all the calcium located?
A
sarcoplasmic reticulum
20
Q
in the sarcoplasm there is no calcium until when?
A
time to contract
21
Q
What is the functional unit of muscle contraction?
A
sarcomere
22
Q
Myosin is found on the ______ filament>
A
thick
23
Q
Actin is on the _____ filament.
A
thin
24
Q
Myosin is what type of contractile protein?
A
molecular motor
25
WHat blocks what in the thin filament?
tropomyosin blocks troponin
26
What is the protein that makes the Z-line? and what is its function?
alpha actin
| anchors the thin filaments together very dense
27
what separates one sarcomere from another?
z-line
28
What is the myosin anchored to?
not it is freely floating in the middle
29
How is muscle filaments moved to contract muscle?
sliding filament theory nothing shortens just slides
30
when looking at a sarcomere through a light microscope what gives the different regions and what are they?
The different regions of the sarcomere are made form the amount of light that passes through the sarcomere.
z line- dark
i band-light
a band dark
h zone-relatively darker than i light than A
31
What is the i band? and what does the i stand for
where light passes through only the thin filaments and i stands for isotropic
light
32
What is the a band? and what does the a stand for?
light passes through thick filament and thin
a=anisotrophic
dark
33
What is h zone?
light only passes through thick filaments lighter than A darker than I
34
what is the m-line?
stains a little dark where the myosin like linked together
35
During contraction what happens to the bands in the sarcomere?
z-lines are pulled together due to the myosin-g actin subunit crossbridge formation
I band goes away
H zone goes away
36
muscle are graded or all or none response?
all or none
37
What happens in act 1 aka resting stage of muscle contraction?
- ADP +P1 that was generated by the atpase activity on the myosin globular head is attached to the myosin head
- myosin heads point toward the z line
38
Everytime a molecule or some structure detaches or attaches to something what happens?
a conformational change
39
In the resting stage where do the myosin heads point?
towards the z line
40
What happens in stage two aka crossbridge formation of muscle contraction?
1. Ca is released from the sarcoplasmic reticulum into the sarcoplasm and binds to troponin
2. Ca2+ and troponin---->conformational change-----> tropomyosin shifts
3. tropomyosin shift frees actin and crossbridge forms between actin and myosin
41
in the crossbridge formation when ca bonds to troponin what happens?
conformational change and tropomyosin shifts
42
What happens in the thrid stage/power stroke of muscle contraction?
Mysosin heads shift away from the z line toward the m line and the crossbridge remains entact oulling the thin filaments toward the m-line.
The shift of the myosin causes a conformational change that results in the ADP and Pi to fall off
43
why in the power stroke do the myosin heads shift away from the z line and towards the m line?
The attachement of the myosin heads and the actin forms a cross bridge causing the myosin heads to shift-conformational change
44
In the power stroke what happens to the ADP and Pi when it falls off of the myosin head?
taken to the mitochondria to remade as ATP
45
The fourth stage of muscle contraction is what?
the release stage
46
what happens in the final release stage of muscle contraction?
In the power stroke the falling off the ADP and Pi causes a conformational change that results deformation of the myosin globular head allowing ATP to bind. ATP binds to the myosin head---> conformational change which results in the breaking of the cross bridge. WHen the crossbridge breaks---conformational change so the ATP that was there is cleaved to ADP and Pi that sticks to the myosin head and the myosin head shifts back toward the z line
47
As long as what two molecules are present in the sarcoplasm , the myosin with undergo ratchetting. what are the 2 molecules and what is ratchetting?
Ca2+ and ATP
| Ratchettig is the rapid shifting of the myosin heads back and forth from the z line to m line
48
Ratchetting can occue why?
beaciuse allt he myosin heads operate indendently of one another some may be in stage one or three etc. like a tug of war.
49
How is the excitation/depolarization that sweeps across the sarcolemma event and the contraction event coupled?
This happens via a second messenger IP3. The depolarization event goes down the t tubular system and in the t tubular system a cascade reaction takes place that results in the release of IP3. IP3 migrates from t tubule to the terminal cisternae membrane and when it comes in contact with the membrane it cause it to become permeable to calcium. calcium released and you get all those four stages of contraction.
50
what is the second messenger that is responsible for the excitation-contraction coupling?
inositol triphosphate
51
In muscles at what level is the response always all or none?
cell level
52
At what level can you recruit different motor units? and what is this called?
muscle level
| motor unit theory
53
Nerves in muscles may have many coaxons attached to it. What is the relationship between the amount of coaxons and muscles attached to the nerve and its movement ability?
calf muscles-motor units are about 200 per neuron
hands muscle-20-30 motor units-more precise/delicate movement
more precision in movement the less muscle fibers
54
WHat do the various muscles types allow for animals?
They allow different animals to be differently adapted to their environment
55
Give an example of the variability of muscles types say between humans and a rattlesnake?
Rattlesnakes have extremely quicker adapted muscles than the muscles in our legs when we ru for instance they must be placed on a slow motion camera in order to view their strike
56
What is the muscle type on the clam and how is it adapted?
It is a tiny muscle but exerts enormous amount of force to be able to hold the two shells of the clam together especially when someone is trying to pull them apart. This muscle is a cylindrical muscle giving it a greater cross sectional area to interact with the valve
57
what is the muscle force/strength determined by?
Not the size of the muscle but the cross sectional area of the muscle
58
What is the relationship between the cross sectional area of the muscle and its strength?
directly related
59
Who is the fastest striker int he animal kingdom?
It is not the rattlesnake it is a toss up between the somatopods and pistal shrimp
60
What are the two major muscle subtypes within striated muscle?
tonic muscle and phasic
61
What is tonic muscle?
slow contracting and slow relaxing-prolonged contraction and generally do not require an action potential
62
What is phasic muscles?
muscle twitch-rapid burst like response of a twitch
63
What is one of the best studied groups for striated tonic muscle? and what does this muscle control in these groups?
reptiles amphibians and birds AND IT CONTROLS POSTURE
64
Striated tonic muscles are responsible for posture in what group of animals?
reptiles amphibians and birds
65
What muscle type do humans use for posture?
slow phasic striated muscle fibers
66
What are slow phasic striated muscle fibers?
slow contracting
slow fatiguing
Contain large numbers of mitochondria
Contain large amounts of myoglobin
67
Why do slow phasic striated muscle fibers contain large amounts of mitochondria?
they are postural muscles that are working continuously
68
What is myoglobin?
Pigments found in muscles that is dark in color and is a simpler form of hemoglobin made of a single protein that stores oxygen
69
What are fast phasic oxidative fibers found in striated muscle?
Quick to contract and fatigue very slowly.
| Contain large numbers of mitochondria-darker in color sometimes called red muscles
70
What are fast phasic glycolytic fibers in striated muscle?
Quick to contract and very powerful but fatigue quickly
| Can operate in the absence of oxygen
71
What do fast oxidative fibers fatigue slowly?
They are oxidative. They use oxygen continuously. As long as there is blood supply with oxygen they will continue to work.
72
What is typically know as dark muscle?
fast phasic oxidative fibers
73
What is the type of muscle fiber that is normally found in the breast muscles of birds that fly for long distances and why?
The wings are very energy intensive since they must be in constant motion when they are flying and will have darker muscles along the breast-fast phasic oxidative fibers
74
What type of muscle fiber is found in the breast muscles of turkeys and chickens that dont fly very much and why?
fast phasic glycolytic fibers becasue they dont need to constantly use those muscle
75
How can you tell the type of activity an animal participates in?
Based on the types of muscle fibers and where they are found. For example chickens don't fly long distances but run around farms they would have fast phasic oxidative fibers in their legs and fast phasic glycolytic fibers in their breasts. The opposite would be true for fowl such as quails who migrate by flying
76
Describe the difference between cardiac muscle and skeletal muscle innervation.
Both are senstitial aka multi nucleated. In skeletal muscles they are individually innervated by neurons there is a specific neuron for a specific muscle and they all connect to the muscle at the motor end plate. Cardiac muscle is more diffusely innervated and has no motor end plates.
77
What does the individual innervation of skeletal muscle allow to happen?
motor unit recruitment
78
What happens to stimulate skeletal muscle contraction?
At the motor end plate acetylcholine is the neuromuscular transmitter substance. The neuron sends an action potential down to the axonal batons acetylcholine is released and it interacts with the motor end plate to trip gates that result in muscle contraction.
79
Where does the neuron innervate the skeletal muscle?
always the same place the motor end plate
80
what is the neuromuscular transmitter in vertebrates?
acetylcholine
81
what type of muscle must contract in a very organized fashion in order to produce unified movement of your arm of leg or etc?
striated muscle
82
What type of striated muscle has no motor end plates?
cardiac
83
What is the diffuse innervation in cardiac muscles?
The innervation is more diffuse and groups of muscles are diffusely innervated so the whole group contracts together
84
Groups of cardiac muscle are connected by what? and what does this allow?
intercalated disks
the electrical connectivity allows the muscles to be diffusely activated at one area and finds it way down as the muscles contract atrium-->ventricle
85
In general terms how is the contraction of skeletal muscle different form cardiac?
In skeletal everything goes at one time and in cardiac tends to start at one end and sweeps across to get more control of contraction and efficient emptying of ventricles and atrium
86
What contraction lasts longer:cardiac muscle contraction or skeletal muscle contraction?
cardia muscle contraction
87
How is the structure of the t tubular system different on skeletal muscle and cardiac muscle?
The t tubular system in skeletal muscle is sloppy-all depending on the spacing which is generally pretty evenly spaced. In cardiac muscle you cant afford to have some sarcomeres that do not contract so the t tubular system is much more extensive there is more of them and innervate more completely through the bundles of muscle
88
What type of heart do humans have compared to invertebrates?
We have a myogenic heart where the heart beat originates in the heart muscle whereas invertebrates have a neurogenic heart where the cns controls their heart beat
89
Does smooth muscle contain sarcomeres?
Yes they just don't contain them in the same organized arrangement as in striated muscle.
90
How are the myofilaments distributed in smooth muscle?
randomly
91
In vertebrates what is the cell shape of smooth muscle?
spindle shaped-longer than wide
92
Smooth muscle cells have a lot of _____ and not alot of ______. and what does this cause?
Surface area
volume
causes the sarcoplasmic reticulum to be very simple
93
How is the smooth muscle cell innervated?
In various places they look like little bumps on the outside of the cell. These bumps are where the nerves innervate and are called varicosities
94
Are smooth muscle cells uninucleated or multinucleated?
uninucleated
95
Most smooth muscle is under what control? What is the exception?
The autonomic nervous system
| urinary bladder
96
What is the regulatory protein of smooth muscle?
CALMODULIN
97
Where is smooth muscle normally found?
around hollow organs
