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

3:56 minutes

Problem 1

Textbook Question

When the semilunar valves are open, which of the following are occurring?
(1) Coronary arteries fill
(2) AV valves are closed
(3) Ventricles are in systole
(4) Ventricles are in diastole
(5) Blood enters the aorta
(6) Blood enters pulmonary arteries
(7) Atria contract
a. 2, 3, 5, 6
b. 1, 2, 3, 7
c. 1, 3, 5, 6
d. 2, 4, 5, 7

Verified step by step guidance

Step 1: Understand the function of the semilunar valves. These valves (aortic and pulmonary valves) open during ventricular systole to allow blood to flow from the ventricles into the aorta and pulmonary arteries, respectively.

Step 2: Analyze the state of the ventricles when the semilunar valves are open. During this phase, the ventricles are in systole (contraction), which generates the pressure needed to open the semilunar valves and propel blood into the aorta and pulmonary arteries.

Step 3: Determine the state of the atrioventricular (AV) valves. When the semilunar valves are open, the AV valves (tricuspid and mitral valves) are closed to prevent backflow of blood into the atria during ventricular contraction.

Step 4: Identify where blood is flowing. When the semilunar valves are open, blood is ejected from the ventricles into the aorta (systemic circulation) and pulmonary arteries (pulmonary circulation).

Step 5: Eliminate incorrect options by considering the phases of the cardiac cycle. For example, atrial contraction (diastole) and coronary artery filling occur primarily during ventricular diastole, not systole. Use this information to select the correct combination of events.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Cardiac Cycle

The cardiac cycle refers to the sequence of events that occur during one heartbeat, including the contraction and relaxation of the heart chambers. It consists of two main phases: systole, when the heart muscles contract to pump blood out, and diastole, when the heart relaxes and fills with blood. Understanding this cycle is crucial for analyzing the function of the heart valves and the flow of blood.

Heart Valves

Heart valves, including the semilunar and atrioventricular (AV) valves, regulate blood flow through the heart. The semilunar valves open to allow blood to exit the ventricles into the aorta and pulmonary arteries during systole, while the AV valves close to prevent backflow into the atria. Recognizing the role of these valves is essential for understanding the conditions under which they open and close.

Coronary Circulation

Coronary circulation refers to the flow of blood to and from the tissues of the heart muscle itself. During diastole, when the heart is relaxed, the coronary arteries fill with blood, supplying oxygen and nutrients to the heart. This concept is important for understanding how the heart receives its blood supply and the timing of this process in relation to the cardiac cycle.

Watch next

Master Systole, Diastole, Pressure, & Valves with a bite sized video explanation from Bruce Bryan

Start learning

Related Videos

Related Practice

Textbook Question

More than one choice may apply.

Given a volume of 150 ml at the end of diastole, a volume of 50 ml at the end of systole, and a heart rate of 60 bpm, the cardiac output is

a. 600 ml/min

b. 6 liters/min

c. 1200 ml/min

d. 3 liters/min

547

views

Textbook Question

Describe how heart contraction and relaxation influence coronary blood flow

Name the major branches of the coronary arteries, and note the heart regions served by each

332

views

Textbook Question

Freshly oxygenated blood is first received by the:

a. Right atrium

b. Left atrium

c. Right ventricle

d. Left ventricle

358

views

Textbook Question

The sequence of contraction of the heart chambers is:

a. Random

b. Left chambers followed by right chambers

c. Both atria followed by both ventricles

d. Right atrium, right ventricle, left atrium, left ventricle

723

views

Textbook Question

Mrs. Hamad, a middle-aged woman, is admitted to the coronary care unit with a diagnosis of left ventricular failure resulting from a myocardial infarction. Her chart indicates that she was awakened in the middle of the night by severe chest pain. Her skin is pale and cold, and moist sounds of pulmonary edema are heard over the lower regions of both lungs. Explain how failure of the left ventricle might cause these signs and symptoms.

456

views

Textbook Question

What are the valves in the heart, and what is the function of each?

544

views

Textbook Question

More than one choice may apply.

Soon after the onset of ventricular systole, the

a. AV valves close.

b. semilunar valves open.

c. first heart sound is heard.