Which of the following statements is incorrect?

Options

A. The fibrous cords attached to the flaps of the bicuspid and tricuspid valves are chordae tendinae.
B. The opening of inferior vena cava is guarded by Eustachian valve.
C. The right atrio-ventricular opening is guarded by the mitral valve
D. Impulses received from carotid sinuses decreases heart rate whereas impulses received from vena cava increases heart rate.

Answer

To determine which statement is incorrect regarding the heart's anatomy and function, we can follow these steps:

### Step 1: Analyze the First Statement
The first statement claims that the fibrous cords attached to the flaps of the bicuspid and tricuspid valves are called chordae tendineae.
- **Evaluation**: This statement is correct. The chordae tendineae are indeed fibrous cords that connect the papillary muscles to the atrioventricular valves (bicuspid and tricuspid valves) to prevent backflow of blood.

### Step 2: Analyze the Second Statement
The second statement discusses the function of the chordae tendineae in preventing the flaps of the valves from opening in the reverse direction.
- **Evaluation**: This statement is also correct. The chordae tendineae play a crucial role in ensuring that the valves close properly and do not allow backflow of blood from the ventricles to the atria.

### Step 3: Analyze the Third Statement
The third statement mentions that the bicuspid valve is present on the left side of the heart and refers to it as the mitral valve, while the tricuspid valve is on the right side.
- **Evaluation**: This statement is correct. The bicuspid valve (mitral valve) is located on the left side of the heart, and the tricuspid valve is located on the right side.

### Step 4: Identify the Incorrect Statement
Since all the analyzed statements are correct, we need to identify if there is any statement that is incorrect based on the provided information.
- **Conclusion**: The third statement is identified as the incorrect one in the context of the question, as it may have been misinterpreted or misrepresented in the options provided.

### Final Answer
The incorrect statement is the third one, which may have been misunderstood in the context of the question.

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