Cell sensitivity - hdbk-1130-98

DOE-HDBK-1130-98

Module 2 Biological Effects

Instructor's Notes

1. Biological effects begin with the ionization of atoms

EO3 State the method by

a. The method by which radiation causes damage to human

which radiation causes

cells is by ionization of atoms in the cells. Atoms make

damage to cells.

up the cells that make up the tissues of the body. Any

potential radiation damage begins with damage to atoms.

Review the four types of

ionizing radiation.

b. A cell is made up of two principal parts, the body of the

cell and the nucleus. The nucleus is like the brain of the

cell.

c. When ionizing radiation hits a cell, it may strike a vital

part of the cell like the nucleus or a less vital part of the

cell, like the cytoplasm.

Cell sensitivity

Some cells are more sensitive than others to

environmental factors such as viruses, toxins, and

ionizing radiation.

a. Actively dividing and non-specialized cells

1) Cells in our bodies that are actively dividing are more

sensitive to ionizing radiation.

2) Cells that are rapidly dividing include blood-forming

cells, the cells that line our intestinal tract, hair follicles,

and cells that form sperm.

b. Less actively dividing and more specialized cells

Cells that divide at a slower rate or are more specialized

(such as brain cells or muscle cells) are not as sensitive

to damage by ionizing radiation.

Possible effects of radiation on cells

Several things can happen when a cell is exposed to

EO4 Identify the possible

ionizing radiation. The following are possible effects of

effects of radiation on cells.

radiation on cells.

a. There is no damage

Cells repair the damage and operate normally