Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 36m
3. Energy & Cell Processes10h 6m
4. Tissues & Histology10h 3m
5. Integumentary System2h 20m
6. Bones & Skeletal Tissue2h 16m
7. The Skeletal System2h 35m
8. Joints2h 17m
9. Muscle Tissue2h 33m
10. Muscles1h 11m
11. Nervous Tissue and Nervous System1h 35m
12. The Central Nervous System1h 6m
- Introduction to the Central Nervous System
  18m
- The Cerebrum
  48m
13. The Peripheral Nervous System1h 26m
14. The Autonomic Nervous System1h 38m
15. The Special Senses2h 41m
16. The Endocrine System2h 48m
17. The Blood3h 22m
18. The Heart3h 42m
19. The Blood Vessels3h 35m
20. The Lymphatic System3h 16m
21. The Immune System14h 37m
22. The Respiratory System3h 20m
23. The Digestive System2h 5m
24. Metabolism and Nutrition4h 0m
25. The Urinary System2h 39m
26. Fluid and Electrolyte Balance, Acid Base Balance37m
27. The Reproductive System2h 5m
28. Human Development1h 21m
29. Heredity3h 32m

9. Muscle Tissue

Sliding Filament Theory and the Sacromere

Anatomy & Physiology

9. Muscle Tissue

Sliding Filament Theory and the Sacromere

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Multiple Choice

What happens when troponin and tropomyosin block the active sites of actin in the sarcomere?

ATP is hydrolyzed to provide energy for muscle contraction.

Muscle contraction is inhibited because myosin cannot bind to actin.

The sarcomere shortens, leading to muscle contraction.

Calcium ions are released from the sarcoplasmic reticulum.

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Verified step by step guidance

Begin by understanding the structure of the sarcomere, which is the functional unit of muscle contraction. It contains actin and myosin filaments.

Recognize the role of troponin and tropomyosin in muscle contraction. Troponin is a complex of three proteins that binds to tropomyosin and helps regulate the interaction between actin and myosin.

Identify the function of tropomyosin, which is a protein that covers the active sites on actin filaments, preventing myosin from binding to actin when the muscle is relaxed.

Understand that when troponin and tropomyosin block the active sites of actin, myosin heads cannot attach to actin filaments, thus inhibiting muscle contraction.

Note that for muscle contraction to occur, calcium ions must bind to troponin, causing a conformational change that moves tropomyosin away from the active sites on actin, allowing myosin to bind and initiate contraction.