A&P Sem I Review: Muscle System
1. What are the five primary functions of the muscle system?
a.
b.
c.
d.
e.
2. Use the following word bank to label the diagrams below:
muscle fiber, epimysium, fascicle, endomysium perimysium
3. Mary wants to enter a weight-lifting competition and consults you as to what type of muscle fibers she needs to develop and how she should go about it. What would you suggest to her?
4. Draw a sarcomere and label all of the components.
5. Where would you expect the greatest concentration of calcium ions to be in a resting skeletal muscle fiber?
6. What is the sliding filament theory of muscle contraction?
7. Rigor mortis that occurs in skeletal muscle a few hours after death is due to
a. excessive ATP and decreased permeability to calcium
b. decreased ATP an increased permeability to calcium
c. excessive ATP
d. lack of oxygen
e. lactic acid buildup.
8. Muscle relaxing drugs are administered to a patient during major surgery. Which of the two chemicals described next would be a good skeletal muscle relaxant and why?
a. Chemical A binds to and blocks Ach receptor of muscle cells
b. Chemical B floods the muscle cell's cytoplasm with Ca++
9. Myasthenia gravis is caused by the loss of ACh receptors on the motor end plate. What would be the primary symptom of this disease?
a. Complete muscle contraction
b. Complete muscle paralysis
10. Invertebrates possess muscles similar to vertebrate skeletal and smooth muscle. An interesting adaptation has been discovered in the muscles that hold clam-shells closed. The thick filaments of these muscle fibers contain a unique protein called paramyosin that allows the muscles to remain in a fixed state of contraction for as long as a month. From you knowledge of the cellular mechanisms of contraction, propose a hypothesis to explain how paramyosin might work.
11. Match the following terms with their definitions/descriptions.
a. motor unit ___ unused muscles become smaller and weaker
b. recruitment ___ a motor neuron and the muscle fibers it innervates
c. muscle tone ___ the activation of more and more motor units
d. atrophy ___ tension in the muscle rises and the muscle shortens
e. isotonic ___ the resting tension in a skeletal muscle
f. isometric ___ the muscle doesn't change length, but tension increases.
12. A motor neuron controls very many muscle fibers. Is this motor unit more likely to be in the muscles of the eye or the muscles of the leg?
13. What are two ways that ATP can be generated in skeletal muscle? What is the role of creatine phosphate in skeletal muscle fibers?
14. Which type of muscle fiber is associated with force?______endurance?______
15. Anaerobic endurance is the length of time that muscle activity can be supported by ______and existing energy reserves of ATP and CP. Aerobic endurance is the length of time a muscle can continue to contract while supported by the ______.
16. Cardiac muscle fibers and smoother muscle fibers have only a single nucleus. What do skeletal muscle fibers have many nuclei?
17. A microscope slide of muscle tissue shows intercalated discs and a single nucleus. Can you definitively determine the specific type of muscle fiber it is? Support your answer with facts.