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

Thin filaments are composed of how many strands of fibrous actin?

One

Three

Two

Four

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Verified step by step guidance

Understand that thin filaments are part of the muscle fiber structure, specifically within the sarcomere, which is the basic unit of a muscle's contraction mechanism.

Recognize that thin filaments are primarily composed of actin, a protein that plays a crucial role in muscle contraction by interacting with myosin, another protein found in thick filaments.

Fibrous actin, also known as F-actin, is a polymerized form of actin that forms long chains or strands. These strands are twisted together to form the backbone of the thin filament.

Identify that the typical structure of a thin filament consists of two strands of fibrous actin twisted around each other, providing the necessary framework for the attachment of other proteins like tropomyosin and troponin.

Conclude that the correct number of strands of fibrous actin in a thin filament is two, as these strands are intertwined to form the filament's structure.