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

18. The Heart

Electrical Conduction System of the Heart

Anatomy & Physiology

18. The Heart

Electrical Conduction System of the Heart

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Multiple Choice

What initiates the release of calcium from the sarcoplasmic reticulum in cardiac muscle cells?

Decreased sodium ion concentration

Action potential reaching the T-tubules

Binding of acetylcholine to receptors

Increased levels of ATP in the cytoplasm

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Verified step by step guidance

Understand the role of the sarcoplasmic reticulum in cardiac muscle cells. It stores calcium ions, which are crucial for muscle contraction.

Recognize that the release of calcium ions is triggered by an action potential. This electrical signal travels along the cell membrane and into the T-tubules.

Learn that T-tubules are invaginations of the cell membrane that help transmit the action potential deep into the muscle cell, ensuring a coordinated contraction.

Identify that when the action potential reaches the T-tubules, it causes voltage-sensitive receptors to open calcium channels in the sarcoplasmic reticulum.

Note that the influx of calcium ions into the cytoplasm initiates the contraction process by interacting with the contractile proteins within the muscle cell.