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

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

How would a decrease in blood volume affect both stroke volume and cardiac output?

It would increase stroke volume but decrease cardiac output.

It would increase stroke volume and cardiac output.

It would have no effect on stroke volume and cardiac output.

It would decrease stroke volume and cardiac output.

Previous problemNext problem

Verified step by step guidance

Understand the relationship between blood volume, stroke volume, and cardiac output. Stroke volume is the amount of blood ejected by the heart in one contraction, and cardiac output is the total volume of blood pumped by the heart per minute, calculated as stroke volume multiplied by heart rate.

Recognize that a decrease in blood volume means there is less blood available to fill the heart during diastole (the relaxation phase), which leads to a reduced end-diastolic volume.

Apply the Frank-Starling law of the heart, which states that the stroke volume of the heart increases in response to an increase in the volume of blood filling the heart. Conversely, a decrease in blood volume will lead to a decrease in stroke volume.

Since cardiac output is the product of stroke volume and heart rate, a decrease in stroke volume due to reduced blood volume will also lead to a decrease in cardiac output, assuming heart rate remains constant.

Conclude that a decrease in blood volume will result in a decrease in both stroke volume and cardiac output, as there is less blood to pump with each heartbeat and overall per minute.