Some of the Stem Cells in Bone Become Osteoclasts During

Multiple Choice

Some of the stem cells in bone become osteoclasts during differentiation.Researchers have shown that chemical signals called cytokines are released into the extracellular fluid by bone stem cells in response to environmental stimuli.The researchers also have shown that the cytokines induce these same bone stem cells to differentiate into osteoclasts.This example illustrates how a(n) _______ signal functions in the human body.

A) autocrine
B) hormone
C) paracrine
D) juxtacrine
E) intracellular