Human Anatomy, Physiology, and Medicine. Anything human!
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First, for me, white blood cell are not a gland... Is it right ?
Second, for me, there are always endocrine...
But the question was "Why are they sometimes endocrine ?"
Could you give me more explanation about this ?
I mean by "always endocrine" that they are never in contact with external environnement... they always stay in
blood or other tissue (like bones).
For example the stomach secretions are not endocrine, because they are evacuate in the external environment
(the intestine) who are in contact with external environment...
arthurius, you need to understand the meaning of the word endocrine. It refers strictly to secretions. An endocrine gland is a gland that releases its secretion into the bloodstream or lymph directly. An endocrine cell is a cell that is either part of an endocrine gland or is a sole-secreting cell. Either way, endocrine refers to the secretion, not the cell itself.
Therefore, saying white blood cells are endocrine cells is not exactly correct(although they do secrete local regulators, collectively called cytokines, that may be considered paracrine horomes if you wish)
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
Yeah, I saw that there is improper perception of the term "endocrine" here. However, thanks to Andrei -- I remember I kept calling him "my good boy" long times ago -- for the explanation, I found it correct.
But still I'm curious about Arthurius' exam question "Why white blood cell are sometimes endocrine gland and not always ?" I think there's something wrong in the question If what Arthurius meant about "not always endocrine" is exactly like what Andrei explained, so maybe I could give something here, hopefully it helps.. If not, then just ignore it
There are several types of white blood cells (RBCs), which each has specific functions, particularly in immune system and body clearance. Some cells do eat antigens (e.g. neutrophil and macrophage), some other cells secrete enzyme(s) or other protein substance(s) to kill pathogens (e.g. basophil, acidophil), another cell produces antibody (B-cell), et. etc. Maybe this is what Arthurius meant by "not always endocrine" --> some cells secrete chemical agents to kill pathogens, while another cells doesn't secrete anything to kill pathogens but do phagocytosis
Another thing... maybe someone is interested...
There's a special cell, very well-known, called Dendritic Cell (DC). When it is immature, it stays in tissues, functions to eat antigens (phagocytosis). This happens in innate immune system. When it is mature, it develops into other function than eating, what we call as antigen-presenting cell (APC). It internalizes and brings antigens inside the cell but not digest it, processes that antigen into peptide and present it to T-cell in peripheral lymphoid organ. This happens in adaptive immune system.
Well, I just want to tell that one cell can have more than one function, it also can switch its function in different situation. Hopefully it helps you a bit
all WBC secrete some kind of cytokine....
10 posts • Page 1 of 1
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