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)

Previous problemNext problem

Struggling with Anatomy & Physiology?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

Which cardiac event is detected first by an electrocardiogram (ECG)?

Atrial depolarization

Ventricular depolarization

Atrial repolarization

Ventricular repolarization

Previous problemNext problem

Verified step by step guidance

Understand the function of an electrocardiogram (ECG): An ECG measures the electrical activity of the heart as it progresses through the cardiac cycle. Each wave corresponds to a specific cardiac event.

Identify the key events in the cardiac cycle: The main events include atrial depolarization, ventricular depolarization, atrial repolarization, and ventricular repolarization. These events occur in a specific sequence during the heartbeat.

Recognize the ECG wave components: The P wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T wave represents ventricular repolarization. Atrial repolarization is typically masked by the QRS complex and is not distinctly visible.

Determine the sequence of detection: The ECG detects atrial depolarization first, which corresponds to the P wave. This is the initial electrical event in the cardiac cycle.

Conclude that atrial depolarization is the first cardiac event detected by the ECG, as it initiates the electrical activity of the heart and is represented by the P wave.