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

Choose the true statement.

Smooth muscle depends on the calcium-calmodulin system to regulate contraction, while skeletal muscle relies on the calcium-troponin system to regulate contraction.

Unlike skeletal muscle, smooth muscle does not depend on ATP to fuel contractions.

Unlike skeletal muscle, contraction in smooth muscle does not involve a sliding filament mechanism.

The final signal for contraction in smooth muscle is a rise in extracellular calcium, while the final signal for contraction in skeletal muscle is a rise in intracellular calcium.

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Verified step by step guidance

Understand the role of calcium in muscle contraction: In both smooth and skeletal muscles, calcium ions play a crucial role in the contraction process, but they interact with different proteins.

Identify the calcium-binding proteins: In skeletal muscle, calcium binds to troponin, which is part of the thin filament. In smooth muscle, calcium binds to calmodulin, which then activates myosin light chain kinase.

Examine the energy source for muscle contraction: Both smooth and skeletal muscles require ATP for contraction. ATP is necessary for the cross-bridge cycle and muscle contraction in both types of muscle.

Understand the sliding filament mechanism: Both smooth and skeletal muscles use a sliding filament mechanism for contraction, where actin and myosin filaments slide past each other to shorten the muscle.

Clarify the source of calcium for contraction: In skeletal muscle, the final signal for contraction is a rise in intracellular calcium, primarily from the sarcoplasmic reticulum. In smooth muscle, calcium can enter from the extracellular space, but the final signal involves intracellular calcium as well.