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

Steps of Muscle Contraction

Anatomy & Physiology

9. Muscle Tissue

Steps of Muscle Contraction

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Multiple Choice

What role do calcium ions and ATP play in the process of muscle contraction?

Calcium ions and ATP both bind to myosin, causing it to detach from actin and relax the muscle.

Calcium ions are responsible for breaking down ATP, while ATP binds to actin to initiate contraction.

Calcium ions provide energy for the power stroke, while ATP binds to troponin to expose binding sites on actin.

Calcium ions bind to troponin, allowing myosin to bind to actin, while ATP provides energy for the power stroke.

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Verified step by step guidance

Understand the basic mechanism of muscle contraction: Muscle contraction involves the interaction between actin and myosin filaments within the muscle fibers. This process is regulated by calcium ions and ATP.

Calcium ions play a crucial role in muscle contraction by binding to troponin. Troponin is a regulatory protein associated with the actin filament. When calcium ions bind to troponin, it causes a conformational change that moves tropomyosin away from the binding sites on actin.

Once the binding sites on actin are exposed, myosin heads can attach to these sites, forming cross-bridges. This is a critical step in the contraction process.

ATP is essential for the power stroke of muscle contraction. When ATP binds to the myosin head, it is hydrolyzed to ADP and inorganic phosphate, providing the energy needed for the myosin head to pivot and pull the actin filament, resulting in muscle contraction.

After the power stroke, a new ATP molecule binds to the myosin head, causing it to detach from actin. This detachment is necessary for the cycle to repeat, allowing continuous muscle contraction as long as calcium ions and ATP are available.