Download
muscles n.
Skip this Video
Loading SlideShow in 5 Seconds..
Muscles PowerPoint Presentation

Muscles

249 Vues Download Presentation
Télécharger la présentation

Muscles

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Muscles • Skeletal muscles  review (see also H.P.) • Smooth muscles • Cardiac muscles

  2. MUSCLES - Review

  3. Skeletal Muscles • General information • Muscle fiber structure • Muscle contraction: • the sarcomere • Contraction • Sources of energy • Twitch • Smooth muscle

  4. Muscles • General information • Muscle fiber structure • Smooth muscle • Muscle contraction: • the sarcomere • Contraction • Sources of energy • Twitch

  5. Table 12-1

  6. Muscles • General information • Muscle fiber structure • Muscle contraction: • the sarcomere • Contraction • Sources of energy • Twitch

  7. Figure 12-3a - Overview

  8. Figure 12-3b

  9. Figure 12-3c

  10. Figure 12-3d

  11. Figure 12-3e

  12. Figure 12-3f

  13. Figure 12-4

  14. Figure 12-6

  15. Muscles • General information • Muscle fiber structure • Muscle contraction: • the sarcomere • Contraction • Sources of energy • Twitch

  16. Figure 12-7

  17. Figure 12-8

  18. Muscles • General information • Muscle fiber structure • Muscle contraction: • the sarcomere • Contraction • Sources of energy • Twitch

  19. Figure 12-9 - Overview

  20. Figure 12-10 - Overview

  21. Figure 12-11 - Overview

  22. Muscles • General information • Muscle fiber structure • Muscle contraction: • the sarcomere • Contraction • Sources of energy • Twitch

  23. Figure 12-13

  24. Sources of energy • Aerobic conditions (importance of myoglobin) - ATP - creatine phosphate - glucose – glycogen - Fatty-acids • Anaerobic conditions: • Only 2 ATP per glucose • lactic acid formation

  25. Muscles • General information • Muscle fiber structure • Muscle contraction: • the sarcomere • Contraction • Sources of energy • Twitch

  26. Figure 12-12

  27. Figure 12-14

  28. Figure 12-15

  29. Table 12-2

  30. Figure 12-16 - Overview

  31. Figure 12-17 - Overview

  32. Figure 12-18

  33. Figure 12-19 - Overview

  34. Figure 12-20 – Overview (1 of 3)

  35. Figure 12-24

  36. Smooth Muscles • General information • Muscle contraction

  37. Figure 12-25 - Overview

  38. Figure 12-25a

  39. Figure 12-25b

  40. Figure 12-26

  41. Smooth Muscles • General information • Muscle contraction

  42. General considerations • Many types of smooth muscles • Controlled by APs, paracrines and hormones • Variable electric properties • Contraction and relaxation influenced by many factors

  43. Single unit smooth muscle = contract as one unit  digestive system Multi-unit smooth muscle = each fiber must be associated with an axon terminal varicosity  iris, uterus (not pregnant)

  44. Contraction Figure 12-27 - Overview

  45. The excitatory ion for AP is calcium, not sodium as in skeletal muscle The calcium binding protein is calmodulin, not troponin The binding of myosin and actin occurs through a pathway different from skeletal muscle (MLCK) Muscle stretch can trigger channel opening thus contraction Contraction Figure 12-28

  46. Ca++ must be removed  pumped back in cisternae by an ATPase, expelled in ECF by ATPase pump and Ca/Na antiport Relaxation Figure 12-29

  47. Smooth muscle contraction is not always linked to membrane depolarisation Figure 12-31 - Overview

  48. Cardiac muscles • Contractile fibers: the ones that contract • Conducting fibers: the ones triggering the APs

  49. Difference between skeletal and cardiac contractile muscle fiber: calcium channels open first during the repolarisation phase  plateau A single AP (especially repolarisation) lasts much longer than a skeletal muscle fiber AP The cardiac AP

  50. Figure 14-14 - Overview