Is epithelium vascularized? How do nutrients and oxygen reach epithelium? Why is this feature an important evolutionary acquisition?

Explanation

### Step-by-Step Solution:

1. **Is Epithelium Vascularized?**
- The epithelium is not vascularized. This means that it does not contain blood vessels or capillaries within its structure.

2. **How Do Nutrients and Oxygen Reach Epithelium?**
- Since the epithelium lacks direct blood supply, nutrients and oxygen reach the epithelial cells through the process of diffusion.
- The connective tissues located beneath the epithelium contain blood vessels that supply nutrients and oxygen. These substances diffuse from the blood in the connective tissue into the epithelial cells.
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