The short term effects of radiation on a tissue are determined by the sensitivity of its:
Mesenchymal cells
Ectodermal cells
Parenchymal cells
None of the above
The short-term effects of radiation on a tissue (effects seen in the first days or weeks after exposure) are determined primarily by the sensitivity of its parenchymal cells.
White and Pharoah's Oral Radiology Principles and Interpretation,7th edition