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The pseudopodial process (aka the tanning process) happens slowly in dermal melanocytes in response to ultraviolet light and to production of new melanosomes and increased donation of melanosomes to adjacent keratinocytes, which are typical skin surface cells. Donation occurs when some keratinocytes engulf the end of the melanocyte pseudopodia ...
The functions of pseudopodia include locomotion and ingestion: Pseudopodia are critical in sensing targets which can then be engulfed; the engulfing pseudopodia are called phagocytosis pseudopodia. A common example of this type of amoeboid cell is the macrophage. They are also essential to amoeboid-like locomotion.
It is a crawling-like type of movement accomplished by protrusion of cytoplasm of the cell involving the formation of pseudopodia ("false-feet") and posterior uropods. One or more pseudopodia may be produced at a time depending on the organism, but all amoeboid movement is characterized by the movement of organisms with an amorphous form that ...
Illustration of a melanocyte Micrograph of melanocytes in the epidermis. Through a process called melanogenesis, melanocytes produce melanin, which is a pigment found in the skin, eyes, hair, nasal cavity, and inner ear. This melanogenesis leads to a long-lasting pigmentation, which is in contrast to the pigmentation that originates from ...
The pseudopodia enable gliding motion and occasionally back-and-forth movement. During aggregation, the pseudopodia of multiple cells anastomose , allowing coordinated motion. [ 2 ] Laboratory observations suggest that sorocarps serve as a survival mechanism, compensating for the absence of cyst formation under adverse conditions.
A mole can be either subdermal (under the skin) or a pigmented growth on the skin, formed mostly of a type of cell known as a melanocyte. The high concentration of the body's pigmenting agent, melanin, is responsible for their dark color. Moles are a member of the family of skin lesions known as nevi (singular "nevus"), occurring commonly in ...
Melanocytic nevi and neoplasms are caused by either a proliferation of (1) melanocytes, or (2) nevus cells, a form of melanocyte that lack dendritic processes. [78] [79] Acral nevus (melanocytic nevus of acral skin, melanocytic nevus with intraepidermal ascent of cells) Amelanotic blue nevus (hypomelanotic blue nevus) Becker's nevus; Balloon ...
In some cases the cell moves by "walking", with relatively permanent pseudopodia serving as limbs. The most important genera are Amoeba and Chaos, which are set apart from the others by longitudinal ridges. The best known of the species in this family is Amoeba proteus, commonly used in classrooms to demonstrate movement by pseudopodia.