Term
| Name the three types of muscle tissue? |
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Definition
Skeletal muscle
cardiac muscle
smooth muscle |
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Term
| Do all three muscle types require nerve stimulation to contact? |
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Definition
| No only the skeletal muscle |
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Term
| Structurally describe the skeletal muscle |
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Definition
Voluntary
Striated
Cell fibers are long
Requires nerve stimulation
Each cell acts independently and synapses with one synaptic terminal |
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Term
| Structurally describe the Cardiac muscle |
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Definition
Involuntary
Does not require nerve stimulation
Striated
Cellse Work as a "function syncitium" due to gap junctions that connect them |
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Term
| Structurally describe the smooth muscle |
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Definition
Involuntary
Does not require nerve stimulation
No striations
Two types: Single and multi unit |
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Term
| Describe antagonist muscle pair? |
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Definition
Example triceps and biceps:
flexion: triceps muscle relaxes; and bicep muscle contracts
Extension -tricep muscle contracts and bicep muscle relaxes |
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Term
| What is the anatomy of a whole skeletal muscle? |
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Definition
-Whole muscle
-Muscle fascicles
-Muscle cells (fibers)
-Myofibrils
-Myofilaments |
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Term
| Each myofibril is encased by a _____A____ and oranelle that sequesters _____B_____? |
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Definition
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Term
| Myofibrils cantain what kind of fliaments _____A_____ and ____B____ organized into _____C____ |
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Definition
A. Thick
B. Thin
C. Sarcomeres |
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Term
| invaginations of the plasma membrane that extend deep into the cell so that each myofibril can recieve action potiental |
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Definition
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Term
| What is the Thick Filament (myofilaments) composed of |
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Definition
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Term
| What is the 3 proteins the thin filament is composed of? |
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Definition
1. Actin
2. Troponin
3. Tropomyosin |
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Term
| Contraction in the myofilaments occur when? |
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Definition
| myosin head binds to actin |
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Term
| The position of troponin/tropmyosin controls what for myosin |
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Definition
| Controls the availability of the binding site on actin |
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Term
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Definition
| Largest known protein. Runs from the Z-line to the M-Line. Stablizes the position of the fialament. Helps return stretch muscle to resting length |
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Term
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Definition
Aligns to the actin filaments along the sarcomere
Attaches to the Z-line |
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Term
| Describe the Striated muscle-The sarcomere -A-Band (dark)? |
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Definition
| Entire length of the thick filaments |
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Term
| Describe the Striated muscle-The sarcomere I-Bans (light)? |
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Definition
| Includes only thin filaments |
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Term
| What creates the striated appearance of the sarcomere? |
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Definition
| The alternating A and I Bands |
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Term
| Put the muscles in order of quickest twitch times? |
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Definition
1. Skeletal
2. Cardiac
3. Smooth |
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Term
| Skeletal Muscles (appearance under a microscope; fiber arrangement and Location) |
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Definition
Appearance: Striated
Fiber arrangement: sarcomeres
Location: Attached to bones; A few sphincters close off hollow organs |
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Term
| SMOOTH (appearance under a microscope; fiber arrangement and Location) |
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Definition
Appearance: Smooth
Fiber arrangements: oblique bundles
Location: Forms the walls of hollow organs and tubes; some schincters |
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Term
| Cardiac: (appearance under a microscope; fiber arrangement and Location) |
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Definition
Appearance: Striated
Fiber Arrangement: Sarcomeres
Location: Heart |
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Term
Skeletal
Tissue morphology
Internal structure
Fiber proteins |
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Definition
Tissue morphology: multinucleate: large cylinder fiber
Internal structure: T-Tube and sarcoplasmic reticulum
Fiber proteins: Actin, myosin, troponin and tropomyosin |
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Term
Smooth
Tissue morphology
Internal structure
Fiber proteins |
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Definition
Tissue morphology: uninucleate: small spindle shaped fibers
Internal structure: No t-tubules, sarcoplasmic reticulum reduced or absent
Fiber proteins: Actin; myosin, tropomyosin |
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Term
Cardiac
Tissue morphology
Internal structure
Fiber proteins |
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Definition
Tissue morphology: uninucleate, shorter branching fibers
Internal structure: T-Tubule and sarcoplasmic reticulum
Fiber proteins: Actin, myosin, troponin and tropomyosin |
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Term
Skeletal
Control
Contraction speed
Contraction Force of single fiber twitch |
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Definition
Skeletal
Control: Ca2+ and troponin
Fibers independent of one another
Contraction speed: fastest
Contraction Force of single fiber twitch: Not graded |
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Term
Cardiac
Initiation of contraction:
Neural Control of Contraction:
Hormonal influence on contraction |
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Definition
Cardiac
Initiation of contraction: Auto rhythmic
Neural Control of Contraction: autonomic neurons
Hormonal influence on contraction: Epinephrine |
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Term
Smooth
Initiation of contraction:
Neural Control of Contraction:
Hormonal influence on contraction |
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Definition
Smooth
Initiation of contraction: stretch, chemical signals, can be autohythmic
Neural Control of Contraction: autonomic neurons
Hormonal influence on contraction: multiple hormones |
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Term
Skeletal
Initiation of contraction
Neural Control of Contraction
Hormonal influence on contraction |
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Definition
Skeletal
Initiation of contraction: requires Ach from motor neuron
Neural Control of Contraction: Somatic motor neuron
Hormonal influence on contraction: None |
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Term
Cardiac
Control:
Contraction speed
Contraction Force of single fiber twitch |
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Definition
Cardiac
Control: Ca2+ and troponin
Fibers electrically linked via gap junctions
Contraction speed: Intermediate
Contraction Force of single fiber twitch: Graded |
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Term
Smooth
Control
Contraction speed
Contraction Force of single fiber twitch |
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Definition
Smooth
Control: Ca2+ and calmoduin
Fibers electrically linked via gap junctions
Contraction speed: Slowest
Contraction Force of single fiber twitch: graded |
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Term
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Definition
| Muscle has not shortened; sarcomeres shorten, generating force, but elastic elements stretch, allowing muscle length to remain the same |
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Term
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Definition
| Sarcomeres shorten more but, because elastic elements are already stretched, the entire muscle must shorten |
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Term
Velocity of muscle shortening ________
with increasing loads |
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Definition
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Term
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Definition
| is the time between the muscle AP and the production of muscle tension |
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Term
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Definition
| is when the muscle is generating tensions due to the cross-bridge cycle |
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Term
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Definition
| Is when muscle tension decrease as a result of a decrease in Ca2+ and ending og the cross-bridge cycling |
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Term
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Definition
| due to the time it takes for the nerve to release ACH and cause an AP in the muscle cell. |
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Term
| Myosin -each thick filament is made from ______individual myosin molecules |
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Definition
| 500 individual myosin molecules |
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Term
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Definition
| has a head region, a hinge region and a tail |
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Term
Thin filaments:
Tropomyosin covers up? |
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Definition
| tropomyosin covers up the myosin binding sites on actin. |
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Term
| Describe the role of tropin in a thin filament? |
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Definition
| troponin is a Ca2+ binding protein that helps retain tropomyosin's position on actin |
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Term
| For thin filaments contraction to occur what must happen? |
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Definition
| For a contraction to occur, Ca2+ must bind to troponin, which allows tropomyosin to move and expose the myosin binding site on actin. |
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Term
| Sarcomeres shorten during contraction describe what happens to the H and I? |
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Definition
Zone of Overlap increases
H-Zone Decreases
I-Band Decreases |
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Term
| The sliding filament theory. Describe the 5 steps? |
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Definition
1. Ca2+ levels increase in cytosol
2. Ca2+ binds to troponin
3. troponin Ca2+ complex pulls tropomyosin away from myosin-binding site.
4. Myosin binds to actin and completes power stroke
5. Actin filament moves |
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Term
| Cross-Bridge Cycle Step by step |
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Definition
1. ATP binds to myosin. Myosin releases action
2. Myosin hydrolyses ATP. Myosin head rotates and binds to actin.
3. Power stroke
4. Myosin releases ADP |
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Term
| Describe the role of ATP in the Cross Bridge Cycle? |
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Definition
- ATP binding to the myosin head breaks the cross-bringe (connection between actin and myosin) this allows the myosin head to go back to the cocked position to get ready for another cycle.
-Engergy released from ATP hydrolysis engergy for the power stroke. (myosin head pulling actin towards the center of the sacromere) |
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Term
| Muscles have enough ATP for how many twitches? |
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Definition
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Term
The neuromuscular junction and excitaation contraction coupling?
7 steps |
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Definition
1. somatic motorneuron releases ACh at neuromuscular junction.
2. Net entry of Na+ through ACh receptor-channel intiates a muscle action potiental.
3. Action potiental in t-tubule alters conformation of DHP receptor
4. DHP receptor opens RyR Ca2+ release channels in sarcoplasmic reticulum and Ca2+ enters cytoplasm.
5. Ca2+ binds to troponin, allowing actin-myosin binding
6. Myosin heads execute power stroke.
7. actinfilament slides toward center of sacrcomere |
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Term
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Definition
Is a motor neuron and all of the muscle cells (fibers) it innervates
Motor units are variable in size. |
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