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

18. The Heart

Electrocardiogram (ECG)

Anatomy & Physiology

18. The Heart

Electrocardiogram (ECG)

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Multiple Choice

Which part of the ECG reflects the depolarization of the ventricles and repolarization of the atria?

P wave

T wave

QRS complex

PR interval

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Verified step by step guidance

Understand the components of an ECG: An electrocardiogram (ECG) is a recording of the electrical activity of the heart. It consists of several waves and intervals that represent different phases of the cardiac cycle.

Identify the P wave: The P wave represents the depolarization of the atria, which is the electrical activity that triggers atrial contraction.

Identify the T wave: The T wave represents the repolarization of the ventricles, which is the process of the ventricles returning to their resting state after contraction.

Identify the QRS complex: The QRS complex represents the depolarization of the ventricles, which is the electrical activity that triggers ventricular contraction. It also coincides with the repolarization of the atria, although this is not visible on the ECG because it is masked by the larger QRS complex.

Understand the PR interval: The PR interval is the time from the onset of the P wave to the start of the QRS complex, representing the time taken for the electrical impulse to travel from the atria to the ventricles.