Simple squamous epithelia are mainly concerned with:

Options

A. Diffusion
B. Secretion
C. Absorption
D. Both (b) and (c)

Answer

**Step-by-Step Solution:**

1. **Understanding Simple Squamous Epithelia**:
- Simple squamous epithelia consist of a single layer of flat cells. These cells are thin and allow for easy passage of substances.

2. **Location and Structure**:
- Simple squamous epithelia are found lining surfaces where diffusion and filtration occur, such as in the alveoli of lungs, blood vessels (endothelium), and serous membranes.

3. **Function of Simple Squamous Epithelia**:
- The primary function of simple squamous epithelia is to facilitate the process of diffusion. Because of their thin structure, they allow small molecules to pass through easily.

4. **Permeability**:
- The permeability of simple squamous epithelia means they allow substances to move across their membranes. This is crucial for processes like gas exchange in the lungs and nutrient exchange in capillaries.

5. **Exclusion of Other Functions**:
- Simple squamous epithelia are not primarily involved in secretion or absorption. Their main role is related to diffusion.

6. **Conclusion**:
- Therefore, the main concern of simple squamous epithelia is diffusion, as they are specialized for the passage of small molecules across their membranes.

**Final Answer**: Simple squamous epithelia are mainly concerned with diffusion.

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