1. Challenge Problem 1.Where can smooth muscle be found? 2.Can we control smooth muscle with our brain? 3.Where can we find cardiac muscle? 4.If you had to lose function of one of the types of muscle, which would it be? Why? 5. Which type of muscle cells can have more than one nucleus?*** 6.Why might they need more than one nucleus?***

2. Challenge Problem 1.Identify 2 characteristics of skeletal muscle 2.To which bones of a human did the chicken wing compare? 3.What was that outer covering that wrapped around the muscles and turned into a tendon? 4.Using the words muscle, brain, nerves, tendons, and bones, describe how we move our arms 5.Get out your lab

3. Microanatomy of Muscles Ch. 6b

5. Microscopic Anatomy of Skeletal Muscle Slide 6.9a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Muscle Fibers are composed of bundles of myofibrils Figure 6.3a

6. Microscopic Anatomy of Skeletal Muscle Slide 6.10a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Myofibril  Made of bundles of myofilaments  Myofibrils are aligned to give distinct bands  I band = light band  A band = dark band Figure 6.3b

8. Quick Quiz A muscle fiber is made up of what?

9. Microscopic Anatomy of Skeletal Muscle Slide 6.10b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Sarcomere  Contractile unit of a muscle fiber  Makes muscles contract  Extends from the center of one I band to the center of the next I band Figure 6.3b

10. Microscopic Anatomy of Skeletal Muscle Slide 6.11a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Organization of the sarcomere  Thick filaments = myosin filaments  Thin filaments = actin filaments Figure 6.3c

11. Microscopic Anatomy of Skeletal Muscle Slide 6.12a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Myosin filaments have heads (extensions, or cross bridges)  Myosin and actin overlap somewhat Figure 6.3d

12. Quick Quiz 1 of 3 What are the names of the microfilaments responsible for muscle contraction?

13. Assignment Draw, color, label a muscle & Myofibril

14. Welcome back! 1.The s_______ is the functional unit of the muscle fiber. *** 2.Muscle Fibers are composed of bundles of _______ 3.Epimysium wraps around the inner most cell or the outermost bundle? Circle one 4.Endomysium wraps around something inside or outside? Circle one 5.How do you know the answer for 3 & 4?

15. Properties of Skeletal Muscle Activity Slide 6.13 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Irritability – ability to receive and respond to a stimulus  Contractility – ability to shorten when an adequate stimulus is received

16. Nerve Stimulus to Muscles Slide 6.14 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Skeletal muscles must be stimulated by a nerve to contract Figure 6.4a

17. The Sliding Filament Theory Slide 6.18 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.8

18. Sliding Filament Animation

19. Muscle Response to Strong Stimuli Slide 6.22 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Muscle force depends upon the number of fibers stimulated  More fibers contracting results in greater muscle tension  Muscles can continue to contract unless they run out of energy

20. Tallest person Remind the group about the video last semester when the dude pushed the huge rock off of his chest

21. Energy for Muscle Contraction Slide 6.23 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Initially, muscles used stored ATP for energy  Bonds of ATP are broken to release energy  Only 4-6 seconds worth of ATP is stored by muscles  After this initial time, other pathways must be utilized to produce ATP

22. Challenge Problem 1.Where do humans get the initial burst of energy, about 4-6 seconds? 2. When talking about muscle cells, contract = ________ 3. Epimysium = inner or outer? 4. Endomysium = inner or outer?

23. Energy for Muscle Contraction Slide 6.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Aerobic Respiration  Series of metabolic pathways that occur in the mitochondria  Glucose is broken down to carbon dioxide and water, releasing energy  This is a slower reaction that requires continuous oxygen Figure 6.10c

24. Shortest person Give an example of someone doing aerobic respiration According to the previous chart, describe how humans can lose weight

25. Energy for Muscle Contraction Slide 6.26a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Anaerobic glycolysis  Reaction that breaks down glucose without oxygen  Glucose is broken down to pyruvic acid to produce some ATP  Pyruvic acid is converted to lactic acid Figure 6.10b

26. Lightest Colored Hair Give your group an example of anaerobic respiration

27. Energy for Muscle Contraction Slide 6.26b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Anaerobic glycolysis (continued)  This reaction is not as efficient, but is fast  Huge amounts of glucose are needed  Lactic acid produces muscle fatigue Figure 6.10b

28. Quick Quiz 2 of 3 Stored _____ is used for initial energy in muscles, but only lasts a few seconds. Aerobic respiration provides ATP, but only in the presence of __________ ________ acid is a result of anaerobic glycolysis.

29. Challenge Problem 1. Aerobic respiration uses oxygen or no? 2. Anaerobic respiration uses oxygen or no? 3. Give an example of each pathway to make energy.

30. Muscle Fatigue Slide 6.27 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  When a muscle is fatigued, it is unable to contract  Increasing acidity (from lactic acid) and lack of ATP causes the muscle to contract less

31. Types of Muscle Contractions Slide 6.28 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Isotonic contractions  Myofilaments are able to slide past each other during contractions  The muscle shortens  Ex: Lifting a book  Isometric contractions  Tension in the muscles increases  The muscle is unable to shorten  Ex: Trying to lift a car

32. Muscle Tone Slide 6.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Some fibers are contracted even in a relaxed muscle  Different fibers contract at different times to provide muscle tone  The process of stimulating various fibers is under involuntary control

33. Effects of Exercise on Muscle Slide 6.31 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Results of increased muscle use  Increase in muscle size  Increase in muscle strength  Increase in muscle efficiency  Muscle becomes more fatigue resistant

34. Quick Quiz 3 of 3 Why type of muscle contraction is at work when doing a wall sit? Give an example of an isotonic muscle contraction.

35. Steroid Prevention Poster for Teens Create a poster identifying the dangers of steroid abuse Use the handout as reference Use color and creativity You may even say what steroids are and how they should be used