Name: Teacher: Olsen Hour:
Dem Bones Textbook p84-85, 88-99 61 In all exercises, quizzes and tests in this class, always answer in your own words. That is the only way that you can show that you understand what you are saying. Also, make it a habit to answer in full sentences whenever it is appropriate for the question. You will also be responsible for the vocabulary words listed on p111. 1. What is meant by the term homeostasis? Why is it important? 2. Give one example of negative feedback and one example of positive feedback. Explain how these examples work. 3. What are the five ways the skeletal system helps maintain homeostasis? 4. Become familiar with the structure of bone tissue as shown in figure 5.3 on page 90. 5. Where compact and spongy bone tissues located and what are their functions? 6. How does the skeletal system help maintain calcium levels in the blood? Discuss the types of cells involved. 7. Sketch an osteon. Label the location of blood vessels and bone cells. 8. Matching: Match the O-words to the proper definitions I. Osteon A. the basic unit of structure of compact bone, comprising a haversian canal and its concentrically arranged lamellae II. Osteocyte B. a bone cell; a mature osteoblast that has become embedded in the bone matrix. III. Osteoblast C. A cell from which bone develops; a bone-forming cell. IV. Osteoclast D. Cell that absorbs bone. 9. What are the 3 types of joints? Give at least 1 example of each. 10. Name 3 bones that are found in the appendicular and axial skeletons. 11. What is the difference between tendons and ligaments?
Dem Muscles Textbook p74, 100-111 62 12. For the three types of muscle tissue, compare their appearance, location, and function. 13. Describe the molecular mechanism of muscle contraction, beginning with action potential and including the role of sarcoplasmic reticulum, calcium, troponin-tropomyosin, actin, myosin, and ATP. (You might try sketching it first.) 14. Learn the major muscles as shown in figure 5.15 on page 101. 15. Study figures 5.16 and 5.17. How are the following structures related to each other: Muscles, muscle cells, myofibrils, and sarcomeres. 16. When a muscle contracts, what happens to adjacent z-lines? 17. What is the difference between isotonic contraction and isometric contraction? 18.. What is a motor unit? How can a muscle contraction be made stronger or weaker? 19. What is the difference between temporal summation and tetany?
20. Why can't your muscles contract when they run out of ATP? 63 21. What is the difference between fast and slow muscle tissue? How can training affect the makeup of your muscles? 22. How can a neurotransmitter cause an action potential in a muscle cell? 23. To integrate what we have studied in the last two units, what materials must a muscle cell have available in order to contract repeatedly over a long period of time? 24. Being as specific as you can, describe two reasons why steroids should not be used to increase athletic performance.
64
65
66
67
68
69
70
71
72
73
The Mechanics of Sarcomere Contraction 74 Procedure 1. Everyone in the group should cut out the thick myosin and thin actin filaments along the dotted lines. 2. On a piece of scrap paper, cut out a large bean shape and write "mitochondrion." 3. On another piece of paper, write "sarcoplasmic reticulum". 4. Cut out 10 strips of paper about 0.5 inches by 3 inches from a different color scrap paper. Write troponin/tropomyosin on these. 5. On 5 sticky notes, write "Ca +2 ". 6. On 5 sticky notes of a different color, write "ATP". 7. Place the "Ca +2 " sticky notes on the paper labeled "sarcoplasmic reticulum" and the ones labeled "ATP" place on the paper labeled "mitochondrion". a. Why did you place these sticky notes here? 8. Using the top of a lab bench to represent a muscle cell, construct 2 myofibrils out of inside the cell. Use everyone s thick myosin and thin actin filaments arranged lengthwise in the myofibril to form sarcomeres. 9. Cover the thin filaments (actin) with strips of paper representing the proteins troponin-tropomyosin. 10. Draw the arrangement of these parts from the table in the space below. Include at least 2 sarcomeres. Label the diagram "Muscle Cell at Rest". Label the actin, myosin, Z-lines, sarcomere, myofibril, mitochondria, ATP, SR, Ca +2, and troponin-tropomyosin in your picture. 11. When the muscle is stimulated by a nerve, the plasma membrane depolarizes (a state called "action potential") and the depolarization causes the SR to release its calcium into the cytoplasm of the cell. Release the Ca +2. 12. The calcium binds to troponin, which pulls tropomyosin off the actin. Move the Ca +2 sticky notes to the troponin/tropomyosin. Remove the troponin/tropomyosin.
75 13. With the binding sites on the actin exposed, myosin can bind to it and ATP will power the movement of the actin filaments along the myosin filaments. Adjust the position of the thick and thin filaments to represent a myofibril that has contracted. Draw the new arrangement and label the parts, noting the differences. Label this one Muscle Cell Contraction. Questions 1. What is the role of tropomyosin? 2. What is the role of troponin? 3. What is the role of calcium ions? 4. There are at least three roles played by ATP in the contraction and relaxation of muscle cells. What are they? 5. How is the sarcoplasmic reticulum involved in the contraction and relaxation of a muscle cell? 6. Describe two different situations that could lead to the inability of a muscle cell to contract.
Thick Myosin Filaments: 76 Thin Actin Filaments:
77
Musculoskeletal System Review 78 1. and systems work together to move the body and specific parts. Goal #1: Identify examples of positive and negative feedback loops and describe why they are such. 2. Is this image to the right showing positive or negative feedback loops? Why do you say this? Goal #2: List the 5 ways the skeletal system helps maintain homeostasis. 3. Do as the goal says. Goal #3 Identify the micro-anatomy of bone. 4. Label the diagram of compact bone to the right with the terms osteocyte, osteon, and blood vessel canal. 5. A small section of bone tissue with a Haversian canal for blood vessels and nerves to pass and containing many osteocytes is 6. If bleached human bones found lying in the desert were carefully examined, which of the following would not be present and why? Haversian canals, a marrow cavity, osteocytes, calcium. called: Goal #4: Explain how the skeletal system helps maintain blood calcium levels including the types of cells involved. 7. For young women, the recommended daily value of calcium is 800mg. During a pregnancy, the recommendation is 1200mg per day. Why, and what might happen to a woman s bones without the larger amount? 8. How does skeletal muscle contribute to blood calcium homeostasis? Goal #5: Recognize which major bones (by common name) are in the axial and appendicular skeletons. 9. Using the diagram on the left, make a key and color the appendicular and axial skeletal parts in two different colors.
Goal #6: Choose the type of joint based on overall mobility. 10. What is a joint? 79 11. What type of joint is the knee and why? Goal #7: Identify the micro-anatomy of muscle. 12. What are the 3 types of muscle tissue and what makes each one unique? 13. Sketch and label the fine structure of a muscle. Include labels for muscle fiber, myofibril, sarcomere, z-lines, actin, myosin, and troponin/tropomyosin. 14. What is the basic unit of contraction in a myofibril? 15. The length of a myofibril between two Z lines is called 16. How are the following structures related to each other: Muscles, muscle fibers, myofibrils, and sarcomeres. Goal #8: Explain the sarcomere mechanisms of excitation and contraction 17. How do actin and myosin interact in a sarcomere to bring about muscle contraction? 18. What are the roles of troponin/tropomyosin and the sarcoplasmic reticulum? 19. What are the roles of calcium and ATP in muscle contraction? Goal # 9: Explain how high or low blood calcium levels could affect muscle contraction. 20. Do as the goal says.
Force (gms) Vocabulary 21. Match the M -words with their defining feature: muscle muscle twitch muscle tension myosin marrow metacarpals myofibrils muscle fatigue motor unit a. actin s partner b. all in the hands c. blood cell production d. a muscle cannot contract e. motor unit response f. force exerted by cross-bridges g. muscle cells bundled in connective tissue h. threadlike parts in a muscle i. a motor neuron and all the muscle cells it innervates 80 Goal #10: Identify the types of whole muscle force vs. time graphs. Goal #11: Describe the cause of the trace in the whole muscle force vs. time graphs. 22. What causes the latent period in the graph to the below? What is happening during the contraction phase? 23. Refer to the graph at right: a. Is this isotonic or isometric contraction? b. How did you know? c. What is the max force produced? 24. Refer to the graph at right: a. Is this isotonic or isometric contraction? Force generated by a single stimulus over time b. How did you know the answer? c. What is the weight of the object at the end of the muscle? d. How do you know the answer? 3 2.5 2 1.5 1 0.5 0 0 50 100 150 200 Time (msec)
Active Force (gms) Passive Force (gms) Force (gms) 25. Refer to diagram at right: a. Which part of the graph shows summation? b. What is the physiological cause of summation? c. Which part of the graph shows tetanus? d. If the rapid multiple stimuli are continued for a long time, what will happen? Force generated by multiple stimulus over time 81 6 5 4 3 2 B 1 0 0 50 100 150 200 Time (msec) A 26. What whole muscle phenomenon is observed in the graph to the right? 27. At a molecular level, what is causing more force each time even though the stimulus intensity is the same each time? Goal #12: Describe the roles of active and passive force in muscle contraction. 28. In the graph at right: a. Describe in one sentence what the graph shows. b. In several sentences, explain the physiological reason for trend you describe in part this graph. (Why does this happen?) 2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0 50 100 150 Length (mm) 29. In the graph at right: a. Describe in one sentence what the graph shows. b. In several sentences, explain the physiological reason for trend you describe in part this graph. (Why does this happen?) 2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0 50 100 150 Length (mm)