1. III. Cell Death: Radiant Energy

2. Types of Radiation that Can Cause Cell Damage:
Sunlight (ultraviolet)
X-rays
Radioactive products

3. These forms of radiation can put a charge on different “molecular parts” of the cell and cause damage or death

4. Two theories that focus on Cell Damage Resulting from Radiation:
If the molecules inside a cell become charged, the cell becomes unstable
Also called ionization of cellular constituents
2. If the water within a cell become charged, the cell also becomes unstable

5. They create free radicals
All forms of radiation put a charge on molecules that should not be charged
They create free radicals
Free radicals are very unstable and attempt to bond to other compounds in the cell thus creating more free radicals

8. Two types of Radiation:
Particles (alpha and beta)
Waves (gamma and x-ray)

9. Characteristics of Radiation Relative to Tissue: (Skin Cells)
Alpha particles: Slow speed, little penetration, great amount of damage
Beta particles: Faster speed, greater penetration, less damage per cell
X-ray waves: Even faster speed, greater penetration, little cell damage
Gamma waves: Very fast, goes through most materials, causes very little damage

10. They are inversely proportional
What is the relationship between speed of particles/waves and damage to tissue?
They are inversely proportional
The slower the speed, the greater the damage per cell

11. Radiosensitivity of Different Tissue:
A normal chest x-ray gives off approximately 20 millirads
Not considered harmful if done infrequently

12. Lymphoid tissue (spleen, lymph nodes, etc)
RADIOSENSITIVE: Exposure to 2,500 rads or less causes serious cell damage or death to the following:
Lymphoid tissue (spleen, lymph nodes, etc)
Blood forming organs (bone marrow)
Lining tissue of gastrointestinal tract
Testes
Ovaries
Embryo/fetus—especially early in pregnancy
Cancer

13. What is it that the above assorted tissues have in common such that they are all radiosensitive?
All are undergoing mitosis
What if a mistake occurs here?

14. Growing bone and cartilage
RADIORESPONSIVE: Exposure to rads or less causes serious cell damage or death to the following:
Skin
UVA light
Blood vessels
Growing bone and cartilage
Conjunctiva, lens, and cornea (structures of the eye)

15. RADIORESISTANT: more than 5000 rads may cause cell damage or death
Can take a large dose of radiation
Pituitary
Master gland of endocrine system

16. Adrenal glands
located on top of the kidneys

17. Parathyroid
Maintains calcium levels
functions in bone density

18. Mature bone and cartilage
Liver
Striated muscle
Ex. Biceps
Brain
Thyroid
Pancreas
Kidneys
Mature bone and cartilage

19. Radiation can cause cancer cells, but can also treat cancer without damaging surrounding cells