Fibrous cords which connect the free valve margins and ventricular surfaces of the valve cusps to papillary muscles and ventricular walls?

Appeared in: SCTIMST Staff Nurse - 2016

Explanation

Chordae tendineae are strong, fibrous cords often called 'heart strings'.
As seen in the image, they connect the free margins of the atrioventricular (tricuspid and mitral) valve cusps to the papillary muscles.
Their crucial function is to act as tethers, preventing the valve leaflets from being pushed back into the atria when the ventricles contract.
This anchoring mechanism is essential for maintaining unidirectional blood flow and preventing valvular regurgitation.

Option B: Lunulae are anatomical features of the semilunar (aortic and pulmonary) valves, not the atrioventricular valves. They are the thin, crescent-shaped edges of the cusps and are not fibrous cords.
Option C: The Bundle of His is a critical component of the heart's electrical conduction system, responsible for transmitting electrical impulses to the ventricles. It is not a structural, mechanical component like a cord.
Option D: Kent bundles are abnormal (pathological) accessory electrical pathways between the atria and ventricles. They are not a normal anatomical structure and are associated with pre-excitation syndromes like Wolff-Parkinson-White (WPW).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy of the heart's atrioventricular valves as background academic context rather than a clinical decision trigger.
A nurse assessing a patient post-myocardial infarction must be vigilant for a new, loud systolic murmur, which could indicate acute mitral regurgitation from a ruptured chorda tendinea.
This is a medical emergency as it can lead to rapid hemodynamic collapse from pulmonary edema and cardiogenic shock, requiring immediate notification of the physician and preparation for urgent intervention.
What if? If the papillary muscle ruptures instead of the chordae tendineae, the clinical outcome is the same: acute, severe valvular regurgitation. The entire support system for multiple chordae fails, often leading to a more catastrophic failure of the valve leaflet.

How to Approach the Question

First, analyze the question stem to identify the key anatomical structures being described: 'fibrous cords', 'valve cusps', and 'papillary muscles'.
Next, examine the provided image. Visually identify the structures mentioned. You can see the string-like cords connecting the valve flaps to the muscular pillars.
Correlate the description and the visual evidence with the given options. The term 'Chordae tendineae' literally translates to 'tendinous cords'.
Systematically eliminate the other options by recalling their function. Lunulae are part of a different valve type, while the Bundle of His and Kent bundles are related to the heart's electrical system, not its mechanical structure.

Concept Tested & Keywords

QKVr31HFs1klowOZqrIJMS

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

E6 Anatomy Grays 43e Vol 1 Part 2 p. 47-49

Practise the full SCTIMST Staff Nurse - 2016

Attempt every question from this paper in a timed mock, then review the full solution for each one.