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 Cycle

Anatomy & Physiology

18. The Heart

Cardiac Cycle

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 events occur during the atrial contraction and ventricular filling phase of the cardiac cycle?

The atria contract, pushing blood into the ventricles.

The ventricles contract, ejecting blood into the aorta and pulmonary artery.

The semilunar valves open to allow blood flow into the ventricles.

The atrioventricular valves close to prevent backflow into the atria.

Previous problemNext problem

Verified step by step guidance

Understand the cardiac cycle phases: The cardiac cycle consists of several phases, including atrial contraction, ventricular filling, ventricular contraction, and relaxation.

Focus on atrial contraction and ventricular filling: During this phase, the atria contract to push blood into the ventricles, which are relaxed and filling with blood.

Identify valve actions: The atrioventricular (AV) valves (tricuspid and mitral) are open during atrial contraction to allow blood flow from the atria to the ventricles.

Recognize the role of semilunar valves: The semilunar valves (aortic and pulmonary) remain closed during atrial contraction and ventricular filling to prevent blood from flowing back into the ventricles from the arteries.

Note the transition to ventricular contraction: After the atria contract and the ventricles are filled, the ventricles will begin to contract, leading to the closure of the AV valves to prevent backflow into the atria.