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

Cardiac Action Potentials

Anatomy & Physiology

18. The Heart

Cardiac Action Potentials

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Multiple Choice

By what mechanism does an increase in venous return lead to an increase in stroke volume during the cardiac cycle?

Frank-Starling mechanism

Baroreceptor reflex

Bainbridge reflex

Chemoreceptor response

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Verified step by step guidance

Understand the concept of venous return: Venous return is the flow of blood back to the heart. An increase in venous return means more blood is returning to the heart, particularly to the right atrium.

Learn about the Frank-Starling mechanism: This principle states that the stroke volume of the heart increases in response to an increase in the volume of blood filling the heart (the end diastolic volume) when all other factors remain constant.

Explore how the Frank-Starling mechanism works: As more blood returns to the heart, the cardiac muscle fibers are stretched more. This stretching leads to a more forceful contraction, which increases the stroke volume.

Differentiate from other mechanisms: The baroreceptor reflex, Bainbridge reflex, and chemoreceptor response are different physiological responses. The baroreceptor reflex helps regulate blood pressure, the Bainbridge reflex responds to changes in blood volume, and the chemoreceptor response is related to changes in blood chemistry.

Conclude with the correct mechanism: The increase in stroke volume due to increased venous return is primarily explained by the Frank-Starling mechanism, as it directly relates to the heart's ability to adjust its force of contraction based on the volume of blood it receives.