................ are ridges present inside the auricles .

Explanation

The question asks about the ridges present inside the auricles of the heart. To answer this question, we need to identify the specific structures found within the auricles.

### Step-by-Step Solution:

1. **Understanding the Structure of the Heart**: The heart consists of four chambers: two atria (auricles) and two ventricles. The auricles are the upper chambers of the heart.

2. **Identifying the Auricles**: Each atrium (right and left) has an ear-like projection called the auricle. These auricles help to increase the capacity of the atria and assist in the collection of blood.

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