1. Question 1 Explain the primary differences between smooth, skeletal, and cardiac muscle tissue Skeletal muscle fibers are cylindrical, multinucleate cells, and are the largest fibers of the three types Smooth muscle - no striations and is involuntary found in the wall of hollow organs (viscera) Cardiac muscle - found only in the heart; arranged in spiral or figure 8 shaped bundles joined by intercalated discs

2. Question 2 Describe how striations make up the arrangement of skeletal muscle tissue Due to the alternating dark and light bands within the sarcomere.

3. Question 3 What 3 words are used to describe skeletal muscle tissue? Striated Skeletal voluntary

4. Question 4 What 3 words are used to describe cardiac muscle tissue? Cardiac Striated involuntary

5. Question 5 What are 3 prefixes that indicate they apply to muscle tissue? Myo Mys Sarco

6. Question 6 How do the postural muscles work? Make constant, tiny adjustments as needed They function almost continuously

7. Question 7 What is the role of the sarcolemma in relation to muscle contraction? To act as the “plasma membrane” and function to act as a semi-permeable membrane to the muscle

8. Question 8 Draw and label the parts of an individual sarcomere.

9. Question 9 Explain the roles of the following: Sarcoplasmic reticulum (SR), Thin filament Thick filament SR – smooth ER to store and release Calcium Thin – anchored to the Z line and is the filament that slides during contraction Thick – forms crossbridges to attach to actin during the power stroke phase of contraction

10. Question 10 Where are the following areas on a sarcomere? H zone, M line, Z line, A band, I band

11. Question 11 Define and label the following: Synaptic cleft, Synaptic vesicles, T-tubules

12. Question 12 Explain the effect an action potential would have on a relaxed muscle. Change the permeability of the sarcolemma to sodium causing an influx of + ions generating an AP causing Ca+ to be released from the SR

13. Question 13 How do the crossbridges on a myosin filament work? What is needed so they can function? They link to the actin causing the sliding of the thin filament. Need active site exposure

14. Question 14 What impact does acetylcholine have on a muscle? What is the effect of troponin and tropomyosin? ACh – is the neurotransmitter making what was electrical, become chemical so it can ignite another AP Troponin – actin protein that Ca+ binds to causing a change in the filament Tropomyosin – actin protein that covers up the active (binding) sites on actin preventing the crossbridges from forming

15. Question 15 What energy source is needed to cause the filament to slide and produce a muscle contraction? What does it convert to when energy is released? ATP is the energy source Converts to ADP + Pi when coupled with hydrolysis

16. Question 16 What is the role of Sodium on muscle contraction? Explain its location before and during a contraction. Sodium changes the polarity of the sarcolemma leading to an AP on the muscle due to its positive charge

17. Question 17 Explain each and include the electrical conditions: Polarization, Depolarization, Repolarization Polarization – at rest; Na on outside, K inside Depolarization – Na rushes inward, K out changing the polarity of the sarcolemma Repolarization – restores the muscle to its previous condition of rest in a wavelike fashion

18. Question 18 Identify when Calcium is released and the effect it produces on a muscle Ca+ binds to troponin which moves the tropomyosin off the active or binding sites on the actin preparing the myosin to begin crossbridge formation