Describe structure and role of your chosen specialized cell

Topic: Incredible Cells
Please watch this brief video as an introduction to different types of cells:
Even though the basic composition of most cells are similar, there are many different types of specialized cells found in various organisms. For this discussion please choose one type of cell to research and describe.
Choose one type of cell not yet described by other students (easier the earlier you post!).
Do NOT choose eukaryotic, prokaryotic, plant, animal or bacteria cells (the large categories of cells), rather choose a specialized type of cell found in animals (examples: blood, nerve or sperm cells), plants (examples: guard, epidermal or root hair cells), fungi or bacteria.
Briefly describe the structure and role of your chosen specialized cell. How is this type of cell unique compare to other types of cells?
Include an image of your cell in your post.
You main response should be at least 150 words and include references to all information sources used.