Collagen and elastin are formed by

Options

A. Macrophages
B. Fibroblasts
C. Mast cells
D. Chondrocytes

Answer

### Step-by-Step Solution:

1. **Understanding Collagen and Elastin**:
- Collagen and elastin are types of fibers that are essential components of the skin's supporting structure.
- Collagen provides firmness to the skin, while elastin allows the skin to stretch and return to its original shape.

2. **Identifying the Cells Involved**:
- To determine which cells are responsible for the formation of collagen and elastin, we need to analyze the options provided.

3. **Evaluating Each Option**:
- **Macrophages**: These are immune cells that help in detecting and destroying harmful organisms. They do not synthesize collagen or elastin.
- **Fibroblasts**: These are specialized cells that synthesize the extracellular matrix and collagen. They are crucial for wound healing and are the primary cells responsible for producing both collagen and elastin fibers. This option is correct.
- **Mast Cells**: These cells are involved in the immune response and contain histamine and heparin. They do not play a role in the synthesis of collagen or elastin.
- **Chondrocytes**: These cells are found in cartilage and are responsible for producing and maintaining the cartilaginous matrix, which includes collagen. However, they do not synthesize elastin.

4. **Conclusion**:
- After evaluating all the options, the correct answer is that collagen and elastin are formed by **fibroblasts**.

### Final Answer:
Collagen and elastin are formed by **fibroblasts**.

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