Which muscle features are similar in cardiac and smooth muscles?

Explanation

### Step-by-Step Solution

1. **Identify the Location of Cardiac and Smooth Muscles**:
- Cardiac muscles are found in the walls of the heart.
- Smooth muscles are located in the walls of visceral organs such as the uterus, alimentary canal, urinary bladder, etc.

2. **Examine the Structure of Muscle Cells**:
- Both cardiac and smooth muscle cells have a thin and indistinct sarcolemma (muscle cell membrane). This means that the membrane is not clearly defined and surrounds the muscle cell unevenly.
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