I. Control of Normal Cell Proliferation and Tissue Growth (1). The activity of cell proliferation(增生能力) Labile cells(continuously dividing tissues Surface epithelia, cells of bone marrow hematopoietic tissues Stem cells Stable cells(Quiescent tissues Parenchyma cells of liver, kidneys, and pancreas endothelial cells, lymphocytes, leu kocytes Permanent cells(Nondividing tissues) Neurons. cardiac muscle skeletal muscleⅠ. Control of Normal Cell Proliferation and Tissue Growth (1). The activity of cell proliferation (增生能力) Labile cells (continuously dividing tissues ) Surface epithelia, cells of bone marrow hematopoietic tissues Stem cells Stable cells (Quiescent tissues ) Parenchyma cells of liver, kidneys, and pancreas endothelial cells, lymphocytes, leukocytes Permanent cells (Nondividing tissues) Neurons, cardiac muscle, skeletal muscle