Trypanosomiasis refers to a group of diseases caused by Trypanosoma There are two types of trypanosomiasis that affect humans, they are divided according to their geographical location: African trypanosomiasis, or sleeping sickness, is caused by Trypanosoma brucei parasites in sub-Saharan Africa and is transmitted by the tsetse fly? (Glossina).
Specilized cells in the epidermis called melanocytes produce melanin, a dark pigment that provides skin color. Melanin absorbs ultraviolet radiation in sunlight and preventing mutations in the DNA of skin cells and other damaging effects.ifferences in skin color result from differences in the amount of melanin that melanocytes produce and the distribution and size of pigment granules. Skin color is genetically determined.
In addition to keratinocytes, there are three other types of cells found in the epidermis. Melanocytes are small cells located in the basal layer. These produce pigment known as melanin that helps to protect the skin from UV damage from the sun. Two other cell types found in the epidermis are Langerhans cells and Merkel cells.