LO 3

effects and mechanisms of cellular changes caused by physical agents

Phisycal agents

• radiation• Extreme temperatures• Changes in air pressure suddenly• Electricity flow• mechanical trauma

radiation

any person may be exposed to ionizing radiation from:

1. Daily low-level radiation, from the sun2. direct environmental exposure to large doses

(ex: hirosima and chernobyl)3. diagnostic and therapeutic procedures

2 types of radiation are physically1. Particle rays: ex: alpha, proton, neutron and

electron2. electromagnetic rays: ex: uv, x, gamma

Biological basis:1. ionizing radiation (alpha, protons, neutrons,

electrons, x, and gamma)2. nonionizing radiation (UV rays)

The level of cell damage

Depending on the dose• > 10 gray: Necrosis• 1-2 - gray: cell proliferation is stopped• <0.5 gray: No histopathological effects

burn

Clinical patient burns depends on several factors• it wound• Percentage of body injured• accompanied by other trauma

hyperthermia

result• Heat cramps: electrolytes lost through sweat• Heat exhausted: occurs suddenly, due to the failure of

the cardiovascular system of compensation due to reduced fluid intake

• Heat stroke: a long exposure to heat with high humidity. Termoregulator mechanism fails with a lot of sweat, pores open wide, peripheral vasodilation resulting in significantly reduced blood volume. This situation can occur on death and myocardial muscle

due to changes in atmospheric pressure

• Being in high places: Mountaineers with altitude> 4000 m• The low oxygen tension: increased capillary permeability

pulmonary edema• Explosion: the air or in water

Resulted in the compression of the air blast wave blast that can hit towards ringga chest, abdomen, ruptured organs.

• Low is in place (bottom of the sea or underground tunnels)An increase in oxygen pressure

Increasing the amount of oxygen, nitrogen and helium dissolves in the blood and tissue fluids which resulted in the formation of air bubbles in the blood and tissues lairan result in embolism.

intracellular targets that can be tampered with radiation

a. enzymeb. oxidative phosphorylation in mitochondriac. duplication of DNA and RNA synthesisd. process that completes mitosis and cell

division