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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

Which is the correct order of events in a muscle contraction?

1. Calcium ions bind to troponin, 2. Myosin heads bind to actin, 3. ATP is hydrolyzed, 4. Power stroke occurs

1. Myosin heads bind to actin, 2. Calcium ions bind to troponin, 3. Power stroke occurs, 4. ATP is hydrolyzed

1. Calcium ions bind to troponin, 2. ATP is hydrolyzed, 3. Myosin heads bind to actin, 4. Power stroke occurs

1. ATP is hydrolyzed, 2. Myosin heads bind to actin, 3. Calcium ions bind to troponin, 4. Power stroke occurs

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Verified step by step guidance

Understand the role of calcium ions in muscle contraction: Calcium ions bind to troponin, causing a conformational change that moves tropomyosin away from the binding sites on actin filaments.

Recognize the importance of ATP in muscle contraction: ATP is hydrolyzed to ADP and inorganic phosphate, which provides the energy necessary for the myosin heads to change position and bind to actin.

Identify the binding of myosin heads to actin: Once the binding sites on actin are exposed, myosin heads can attach to these sites, forming cross-bridges.

Describe the power stroke: After binding to actin, the myosin heads pivot, pulling the actin filaments toward the center of the sarcomere, which is known as the power stroke.

Review the sequence of events: The correct order is 1. Calcium ions bind to troponin, 2. ATP is hydrolyzed, 3. Myosin heads bind to actin, 4. Power stroke occurs.