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 to the I band when the sarcomere contracts during muscle contraction?

The I band becomes wider.

The I band remains the same width.

The I band becomes narrower.

The I band disappears completely.

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Verified step by step guidance

Understand the structure of a sarcomere: A sarcomere is the functional unit of a muscle fiber, consisting of overlapping thick (myosin) and thin (actin) filaments. The I band is the region containing only thin filaments and is located on either side of the Z disc.

Learn what happens during muscle contraction: During contraction, the thick and thin filaments slide past each other, shortening the sarcomere. This process is driven by the interaction between actin and myosin filaments, powered by ATP.

Focus on the I band: The I band is the region that contains only thin filaments. As the sarcomere shortens, the overlap between thick and thin filaments increases, reducing the width of the I band.

Compare the options provided: Evaluate each option based on the sliding filament theory. The I band does not become wider, remain the same width, or disappear completely. Instead, it becomes narrower as the filaments overlap more during contraction.

Conclude the correct answer: Based on the sliding filament theory and the structural changes in the sarcomere during contraction, the correct answer is that the I band becomes narrower.