What is the function of chordae tendineae?
Wait, why do they need to anchor the valves? Oh, right, during ventricular contraction (systole), the pressure inside the ventricles increases. If the valves weren't anchored, they might prolapse back into the atria. The chordae tendineae prevent that by keeping the valves from flipping back. So their function is to prevent valve prolapse and ensure the valves close properly, preventing regurgitation.
Looking at the options, the correct answer should be something along those lines. Let's say the options are A: Preventing valve prolapse, B: Initiating heart contractions, C: Regulating heart rate, D: Conducting electrical impulses. Then the correct answer would be A. The other options are incorrect because B and C relate to the SA node or autonomic nervous system, and D refers to the conduction system like the Purkinje fibers.
I should also mention the clinical pearl here. The chordae tendineae are crucial in conditions like mitral valve prolapse. If they're damaged, it can lead to mitral regurgitation. So a key point is that they prevent atrioventricular valve prolapse during ventricular contraction. That's a high-yield fact for exams. Make sure the answer clearly states their role in valve function and the consequences of their dysfunction.
**Core Concept**
The chordae tendineae are fibrous connective tissue structures that anchor atrioventricular (AV) valve cusps to papillary muscles in the ventricles. Their primary role is to prevent valve prolapse and regurgitation during ventricular contraction.
**Why the Correct Answer is Right**
During ventricular systole, the chordae tendineae transmit tension from the papillary muscles to the AV valves (mitral and tricuspid). This prevents the valve leaflets from bulging (prolapsing) into the atria when ventricular pressure rises. By maintaining valve integrity, they ensure unidirectional blood flow from atria to ventricles. Dysfunction (e.g., rupture) leads to AV valve regurgitation.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect if it suggests they initiate heart contractions—this role belongs to the sinoatrial node.
**Option B:** Incorrect if it claims they generate electrical impulses—the conduction system (e.g., Purkinje fibers) handles this.
**Option C:** Incorrect if it describes them as part of the heart’s extrinsic innervation—autonomic nerves regulate heart rate, not the chordae.
**Clinical Pearl / High-Yield Fact**
Mitral valve prolapse (a common pathology) often involves degeneration of chordae tendineae, leading to mitral regurgitation. Remember: “Chordae anchor the valves, not the heart’s rhythm.” Confusion with the conduction system is a classic exam trap.
**Correct Answer: A. Prevent valve prol