Classification of mammalian cells chart

VIM definition

Vegetative Intermitotic Cells

VIM characteristics

Divide rapidly; undifferentiated; no differentiation between divisions

VIM radiosensitivity

Extremely high

VIM examples

Type A spermatogonia; erythroblasts; crypt cells; basal cells

DIM definition

Differentiating Intermitotic Cells

DIM characteristics

Actively divide; more differentiated than VIM; differentiate between divisions

DIM radiosensitivity

High

DIM examples

Intermediate spermatogonia; myelocytes

Vessel/Connective Tissue definition

Cells of vessels & connective tissue (e.g., endothelial, fibroblasts)

Vessel/CT characteristics

Irregular division; more differentiated than VIM/DIM

Vessel/CT radiosensitivity

Intermediate

Vessel/CT examples

Endothelial cells; fibroblasts

RPM definition

Reverting Postmitotic Cells

RPM characteristics

Do not normally divide but retain division ability; variably differentiated

RPM radiosensitivity

Low

RPM examples

Parenchymal liver cells; lymphocytes

Lymphocyte note

Although classed as resistant, lymphocytes are extremely radiosensitive

FPM definition

Fixed Postmitotic Cells

FPM characteristics

Do not divide; highly differentiated

FPM radiosensitivity

Extremely low

FPM examples

Nerve cells; muscle cells; erythrocytes; spermatozoa