1 / 43

Physiology of Strength Training

Physiology of Strength Training Part 1 – Muscle Function Skeletal Muscle Anatomy 660 muscles Approximately 45% of body weight 75% water, 20% protein (12% myofibullar and 8% enzymes, etc) 5% inorganic salts Largest organ system End organ for the primary support systems involved in exercise

Audrey
Télécharger la présentation

Physiology of Strength Training

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Physiology of Strength Training Part 1 – Muscle Function

  2. Skeletal Muscle Anatomy • 660 muscles • Approximately 45% of body weight • 75% water, 20% protein (12% myofibullar and 8% enzymes, etc) 5% inorganic salts • Largest organ system • End organ for the primary support systems involved in exercise

  3. Skeletal Muscle Anatomy • Basement membrane – outer most ‘membrane’ • Plasma membrane or sarcolemma • Satellite cells – between membranes • growth, development, adaptation • under stress they are responsible for hypertrophy and hyperplasia • Multi-nuclei • 200-300 nuclei per millimeter • 85-95% within the scaroplasm • 5-15% in the basement membrane • Tremendous potential for gene alterations

  4. Skeletal Muscle Anatomy • Muscle • Fascicle • Fibers

  5. Skeletal Muscle Structure • Epimysium, Endomysium, and Perimysium converge to form tendons and are very elastic

  6. Skeletal Muscle Anatomy • Muscle • Fascicle • Fibers • Myofibrils • Myofilaments • Actin • Myosin

  7. Skeletal Muscle Anatomy

  8. Skeletal Muscle Anatomy -Myofibrils

  9. Skeletal Muscle Anatomy Sarcomere

  10. Skeletal Muscle Anatomy Myofilaments

  11. Skeletal Muscle Anatomy • What are the three proteins that make up actin? • Actin, tropomyosin, and troponin • What is the function of actin? • What is the function of tropomyosin? • What is the function of tropoin?

  12. Skeletal Muscle Anatomy

  13. Skeletal Muscle Anatomy • Myosin is also referred to as the thick myofilament • Myosin heads • What does myosin use its heads for?

  14. Skeletal Muscle Anatomy • Myosin • Actin • M-line proteins • Titin/Nebulin

  15. Muscle Strength • Where is the strength of a muscle generated? • Muscle strength comes from the interaction of myosin and active • How is the strength of a muscle generated?

  16. Muscle Contraction:Generating Force • Stimulation • Calcium • Actin/Myosin • Sliding • Energy/ATP

  17. Muscle Contraction: Stimulation

  18. Motor Unit • What is a motor unit? • One motor nerve • All the muscle fibers (cells) that it stimulates • Example. 1:4 • Actual MU range from 1:10s to 1:1000s

  19. Neuromuscular Junction • How does a nerve stimulate a muscle fiber? • Neurotransmitter substance • Acetylcholine (ACh)

  20. Neuromuscular Junction • Acetylcholine (acetate and choline) • Reuptake of choline • Fatigue? • Supplement?

  21. Depolarization and Action Potential • Acetycholine • Sodium gates open • Depolarization • Action Potential • Propagation of Action Potential • Sarcolemma • T-tubules

  22. Muscle Contraction: Calcium • After the T-tubule, where does the action potential go? • What is stored in the sarcoplasmic recticulum? • Where does the calcium go? • FYI: Too much lactic acid may block Ca release.

  23. Muscle Contraction: Actin/Myosin • Ca binds to troponin • Troponin causes tropomyosin to shift or move • This uncovers the active sites on the actin. • Once uncovered, the myosin heads will attach to the active site

  24. Muscle Contraction: Sliding • What does the myosin head do once it attaches? • This is called a power stroke. • What happens to the actin? • The myosin breaks away, reattaches, power stroke… • In this case, what happens to the sarcomere?

  25. Actin and Myosin Interaction Charged myosin head and covered active sites. 1. 2. Uncovered active site; myosin head attaches. 3. Power stroke sliding actin inward; myosin head uncharged. 4 ATP separates and recharges myosin head.

  26. Muscle Contraction: Energy • What is ATP? • What does it provide?

  27. ADP + P Energized ADP + P + energy New ATP

  28. Muscle Relaxation • What is needed in order to have the muscle stop contracting? • Stop the impluse • Re-store the calcium • How? Calcium pump • What powers the calcium pump?

  29. Summary of Muscle Contraction 1. Motor Impulse 2. Neurotransmitter Substance 3. Action potential via Na and K 4. Calcium released exposing active sites 5. ATP split forming high energy myosin

  30. Summary of Muscle Contraction 6. Myosin attaches to actin forming a crossbridge 7. Stored energy released and crossbridge movement (Power Stroke) 8. ATP breaks myosin from actin 9. ATP splits forming high energy myosin

  31. Quick Time Movie • Yellow = Calcium • Green = ATP • Gray = ATPase • A Quick Time Movie of the contraction process can be download at the 5230 Web Page

  32. Muscle Strength • So far… • ...Where and how is the strength of a muscle generated? • Next… • ….What makes a muscle stronger? • Acute increase • Chronic increase

More Related