Table of contents

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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

Sliding Filament Theory and the Sacromere

Anatomy & Physiology

9. Muscle Tissue

Sliding Filament Theory and the Sacromere

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Multiple Choice

Which of the following occurs during cross-bridge cycling in the sliding filament theory?

Myosin heads bind to actin filaments, forming cross-bridges.

The sarcomere lengthens as the muscle relaxes.

Calcium ions are actively pumped into the sarcoplasmic reticulum.

ATP is synthesized by the myosin heads.

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Verified step by step guidance

Understand the sliding filament theory: It explains how muscles contract by the sliding of actin and myosin filaments past each other, shortening the sarcomere.

Identify the role of myosin heads: During cross-bridge cycling, myosin heads bind to actin filaments, forming cross-bridges, which is a crucial step in muscle contraction.

Recognize the role of calcium ions: Calcium ions bind to troponin, causing a conformational change that allows myosin heads to bind to actin.

Understand ATP's role: ATP binds to myosin heads, causing them to detach from actin, and is then hydrolyzed to provide energy for the next power stroke.

Clarify the relaxation process: After contraction, calcium ions are actively pumped back into the sarcoplasmic reticulum, and the sarcomere returns to its resting length as the muscle relaxes.