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

Electrical Conduction System of the Heart

Anatomy & Physiology

18. The Heart

Electrical Conduction System of the Heart

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

Why is the QRS complex larger than the P wave in an electrocardiogram (ECG)?

The P wave represents ventricular depolarization, which is a smaller electrical event than atrial depolarization.

The QRS complex represents atrial repolarization, which is a larger electrical event than atrial depolarization.

The QRS complex represents ventricular depolarization, which involves more muscle mass than atrial depolarization.

The P wave represents ventricular repolarization, which is a smaller electrical event than ventricular depolarization.

Previous problemNext problem

Verified step by step guidance

Understand the components of an electrocardiogram (ECG): The ECG is a graphical representation of the electrical activity of the heart. It consists of several waves, including the P wave, QRS complex, and T wave.

Identify the events represented by each wave: The P wave represents atrial depolarization, the QRS complex represents ventricular depolarization, and the T wave represents ventricular repolarization.

Compare the muscle mass involved: Ventricular depolarization involves more muscle mass than atrial depolarization. The ventricles are larger and have thicker walls compared to the atria, resulting in a larger electrical event.

Relate electrical activity to wave size: The size of the wave on the ECG is proportional to the amount of electrical activity. Since ventricular depolarization involves more muscle mass, it generates a larger electrical signal, resulting in a larger QRS complex compared to the P wave.

Clarify common misconceptions: Ensure understanding that the P wave represents atrial depolarization, not ventricular repolarization, and the QRS complex represents ventricular depolarization, not atrial repolarization.