Table of contents

1. Introduction to Anatomy & Physiology5h 43m
2. Cell Chemistry & Cell Components12h 39m
3. Energy & Cell Processes10h 8m
4. Tissues & Histology10h 3m
5. Integumentary System2h 28m
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 System3h 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

Steps of Muscle Contraction

Anatomy & Physiology

9. Muscle Tissue

Steps of Muscle Contraction

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Multiple Choice

What is the ion released from the terminal cisternae that combines with troponin and removes the blocking action of tropomyosin, resulting in the formation of cross bridges?

Cl^-

Na⁺

K⁺

Ca²⁺

H⁺

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Verified step by step guidance

Understand the role of the terminal cisternae in muscle contraction. The terminal cisternae are part of the sarcoplasmic reticulum, which stores calcium ions (Ca²⁺).

Recognize the importance of calcium ions (Ca²⁺) in muscle contraction. When a muscle fiber is stimulated, Ca²⁺ is released from the terminal cisternae into the cytosol.

Identify the interaction between Ca²⁺ and troponin. Ca²⁺ binds to troponin, a regulatory protein associated with the actin filaments in muscle cells.

Explain how the binding of Ca²⁺ to troponin affects tropomyosin. This binding causes a conformational change in troponin, which moves tropomyosin away from the myosin-binding sites on actin filaments.

Understand the formation of cross bridges. With tropomyosin moved aside, myosin heads can attach to actin, forming cross bridges, which is essential for muscle contraction.