Pseudopodia
In some melanocytes, the melanosomes remain static within the cell. In other types of melanocyte, the cell can extend its surface as long pseudopodia, carrying melanosomes away from the center of the cell and increasing the cell's effectiveness in absorbing light.
This happens slowly in dermal melanocytes in response to ultraviolet light, as well as production of new melanosomes and increased 'donation' of melanosomes to adjacent keratinocytes, the normal skin surface cells. This donation comes about because some keratinocytes may engulf the end of the melanocyte pseudopodia, which contain many melanosomes. Cytoplasmic dynein will carry the vesicles containing the melanin to the center of the cell. This causes melanosomes to become sequestered around the keratinocyte's nucleus, providing optimal protection from UV rays.
These changes, together, are responsible for tanning after exposure to UV or sunlight.
Read more about this topic: Melanosome
Famous quotes containing the word pseudopodia:
“The will to power can express itself only against resistances; it seeks that which resists it—this is the native tendency of the amoeba when it extends its pseudopodia and gropes around.”
—Friedrich Nietzsche (1844–1900)