Muscle, Nerve and Neuromuscular Adaptations
Muscle Physiology
Skeletal muscle chemical composition is what % water? protein? and other substances.
Some of the ‘other’ substances that make up muscle include?
What is different about the nucleus in muscles versus other cells in the body?
Terms to know with skeletal muscle physiology: epimysium, perimysium, fasciculi, periosteum, sarcolemma, sarcoplasma, sarcoplasmic reticulum, cytoplasma, actin, myosin, Z line (disk), I band, A band, H zone, A band, troponin, tropomyosin, myofibrils, myofillaments, polarized, transverse tubules, acetylcholine, neuromuscular junction, hypertrophy, hyperplasia, contraction cycling, isoforms
Class, make sure you can draw and label the gross structure of skeletal muscle.
Make sure you can draw and label the sarcomere structure.
How would you describe the sarcomere?
Is a muscle cell the same as a muscle fiber?
What is another name for cytoplasm of the cell?
Describe the purpose of the sarcolemma. Why is it referred to as a polarized plasma membrane? How many lipid layers are there on the plasma membrane? Describe what polarized means?
Draw and label the sarcomere and answer the following.
During a shortening (concentric) muscle action, what happens to the H zone, A band, I band, and Z lines?
During a lengthening (eccentric) muscle action, what happens to the the H zone, A band, I band, and Z lines?
Explain the sliding filament theory. Begin your discussion with the arrival of the nerve impulse to the axon terminal ending. Complete your discussion with return of calcium to the sarcoplasmic reticulum.
What causes the myosin heads to disassociate from the acting binding sites (after the myosin has completed a power stroke).
Explain what a motor unit is? What is the all-or-none phenomenon of motor units?
What is the motor end plate? How is the motor end plate related to the sarcolemma?
What are the different types of muscle fibers? What type of muscle fiber type is recruited for endurance exercise? What type of muscle fiber type is recruited for short-burst explosive work? What fiber type has oxidative and glycolytic characteristics?
Nerve Physiology
Terms to know: dendrites, axon, axon hillock, myelin sheath, swan cells, nodes of ranvier, saltatory conduction, depolarization, hyperpolarization, graded potentials, repolarization, active transport
Approximately how fast is a nerve action potential?
Review what does polarized mean?
Describe what resting membrane potential and the main electrolytes inside and outside the cell.
Disuss what it means for a nerve cell to reach THRESHOLD.
Discuss the steps and processes of a nerve cell at resting membrane potential receiving a stimulus and then propagating an action potential, finally returning to RMP. Can you draw out these steps?
Motor units are recruited by the SIZE principle. This is really controled by the force demands placed on the muscle. Can you explain motor unit recruitment in a concise paragraph?
CLICK HERE FOR a picture of this phenomenon.
What is the all-or-none phenomenon (of motor units) mean?
What is Calcium’s double role in muscular contraction?
Summary of Muscle Contraction? Class, although I have summarized this for you, try to understand it because if you just memorize you can easily make some errors!
SEE PRACTICE QUIZ BELOW!
1. Motor nerve’s impulse action potential arrives at axon terminal of the neuromuscular junction
2. Calcium ions rush in and react with synaptic vesicles
3.Synaptic vesicles fuse with cell membrane
4.Acetylcholine released via process of exocytosis
5.Acetylcholine binds with receptor sites on motor end plate causing depolarization of motor end plate and sarcolemma
6. Impulse travels T- tubules & sarcoplasmic reticulum (SR)
7. Calcium ions released
8. Calcium binds with troponin
9. Shift of tropomyosin, make sites available for myosin
10. With ATP present, ATPase splits ATP to ADP + P + Energy
11. Myosin (S1 units) combine with actin
12. Sliding action of actin over myosin (Power Stroke)
13. Impulse stops to muscle: calcium ions rapidly return to SR
14. Tropomyosin returns over active sites on actin and contraction ceases
Class, for your own personal review from your Biology Class, make sure you are familiar with the functional organization of the nervous system.
What does the muscle spindle respond to within the muscle.
What does the golgi tendon organ (which is located in the tendon) respond to.
Muscular Adaptations to Resistance Training
Go over in detail the hypertrophic factors of resistance training. This is one of the culminating summaries of this section. What increases, what does not change, and what is debatable. Know all of these factors!
The early gains in resistance training are what?
PRACTICE QUIZ OF MUSCLE CONTRACTION! PLEASE NUMBER THE SEQUENCE OF MUSCLE CONTRACTION IN CORRECT ORDER
____Calcium ions released
____Calcium ions rush in and react with synaptic vesicles
____Myosin (S1 units) combine with actin
____With ATP present, ATPase splits ATP to ADP + P + Energy
____Tropomyosin returns over active sites on actin and contraction ceases
____Impulse travels T- tubules & sarcoplasmic reticulum (SR)
____Motor nerve’s impulse action potential arrives at axon terminal of the neuromuscular junction
____Shift of tropomyosin, make sites available for myosin
____Acetylcholine released via process of exocytosis
____Calcium binds with troponin
____Sliding action of actin over myosin (Power Stroke)
____Acetylcholine binds with receptor sites on motor end plate causing depolarization of motor end plate and sarcolemma
____Impulse stops to muscle: calcium ions rapidly return to SR
____Synaptic vesicles fuse with cell membrane
End of Scholarly Questions
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