Which of the following valves guard the opening of the right atrium into the right ventricle and prevent the back flow of blood into the right atrium?

1. A

   Aortic semilunar valve

2. B

   Bicuspid valves

3. C

   Pulmonic valve

4. D

   Tricuspid valves

Appeared in: NHM UP Staff Nurse-2023 shift 1st

Explanation

• The tricuspid valve is an atrioventricular (AV) valve located on the right side of the heart.
• It is situated between the right atrium and the right ventricle, guarding the opening between these two chambers.
• It is named 'tricuspid' because it consists of three leaflets or cusps.
• Its primary function is to open to allow deoxygenated blood to pass from the right atrium to the right ventricle and to close tightly during ventricular contraction (systole) to prevent blood from flowing back into the right atrium.

Why Other Options Were Wrong

• Option A: The aortic semilunar valve is located between the left ventricle and the aorta, not between the right-sided chambers.
• Option B: The bicuspid valve, also known as the mitral valve, is located on the left side of the heart, between the left atrium and the left ventricle.
• Option C: The pulmonic valve is a semilunar valve located between the right ventricle and the pulmonary artery. It prevents backflow into the right ventricle, not the right atrium.

Related Visual

Clinical Relevance

• Nursing practice connection: Knowing Anatomy and function of the heart valves helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
• Auscultation of heart sounds is a fundamental nursing assessment. The first heart sound (S1, the 'lub') is caused by the closure of the atrioventricular valves (tricuspid and mitral), and the second heart sound (S2, the 'dub') is caused by the closure of the semilunar valves (aortic and pulmonic).
• Dysfunction of the tricuspid valve, such as tricuspid regurgitation (leaky valve) or stenosis (narrowed valve), can lead to right-sided heart failure. Nurses must monitor for signs like peripheral edema, jugular venous distention (JVD), and ascites.
• What if? If the question asked about the valve preventing backflow into the left atrium, the correct answer would be the Bicuspid (or Mitral) valve.

How to Approach the Question

• First, break down the question to identify the key anatomical locations: 'right atrium' and 'right ventricle'.
• Next, identify the required function: 'guard the opening' and 'prevent the back flow of blood'.
• Mentally review the four main valves of the heart and their positions relative to the heart chambers.
• Use a mnemonic like 'Try Pulling My Aorta' (Tricuspid, Pulmonic, Mitral, Aortic) to remember the order of valves that blood flows through.
• Match the valve that is located between the right atrium and right ventricle. This is the Tricuspid valve.
• Eliminate the other options based on their incorrect locations: Bicuspid/Mitral (left side), Aortic (leaving left ventricle), and Pulmonic (leaving right ventricle).

Concept Tested & Keywords

• Concept Tested: Anatomy and function of the heart valves.
• Stem keywords: valve, right atrium, right ventricle, prevent back flow
• Lead-in keywords: Which

Question ID

Q0cbTutzYeSWf5fMitP7ke

Copy ID

Reference Book

E6 Anatomy Applied Ashalatha 4e pp. 165-167, 164-166, 163-165