Environmental Hazards

Front 1

environmental emergency

Back 1

A medical condition caused or exacerbated by the weather,
terrain, atmospheric pressure, or other local factors.

Front 2

thermal gradient

Back 2

the difference in temperature between the environment and the body.

Front 3

thermogenesis

Back 3

the production of heat, especially within the body

Front 4

conduction

Back 4

moving electrons, ions, heat, or sound waves through a conductor or
conducting medium.

Front 5

convection

Back 5

transfer of heat via currents in liquids or gases.

Front 6

gamma radiation

Back 6

powerful electromagnetic radiation emitted by radioactive substances
with powerful penetrating properties; it is stronger than alpha and beta radiation.

Front 7

neutron radiation

Back 7

powerful radiation with penetrating properties between that of beta
and gamma radiation.

Front 8

radiation

Back 8

transfer of energy through space or matter.

Front 9

thermoregulation

Back 9

the maintenance or regulation of a particular temperature of the body.

Front 10

core temperature

Back 10

the body temperature of the deep tissues, which usually does not vary
more than a degree or so from its normal 37°C.

Front 11

hypothalamus

Back 11

portion of the diencephalon producing neurosecretions important in the
control of certain metabolic activities, including regulation of body temperature.

Front 12

negative feedback

Back 12

homeostatic mechanism in which a change in a variable ultimately
inhibits the process that led to the shift.

Front 13

basal metabolic rate (BMR)

Back 13

rate at which the body consumes energy just to maintain
stability; the basic metabolic rate (measured by the rate of oxygen consumption) of an
awake, relaxed person 12 to 14 hours after eating and at a comfortable temperature.

Front 14

exertional metabolic rate

Back 14

rate at which the body consumes energy during activity. It is
faster than the basic metabolic rate.

Front 15

heat illness

Back 15

increased core body temperature due to inadequate thermolysis.

Front 16

autonomic neuropathy

Back 16

condition that damages the autonomic nervous system, which
usually senses changes in core temperature and controls vasodilation and perspiration to
dissipate heat.

Front 17

acclimatization

Back 17

the reversible changes in body structure and function by which the body becomes adjusted to a change in environment.

Front 18

heat cramps

Back 18

acute painful spasms of the voluntary muscles following strenuous activity
in a hot environment without adequate fluid or salt intake.

Front 19

heat exhaustion .

Back 19

a mild heat illness; an acute reaction to heat exposure

Front 20

heatstroke

Back 20

acute, dangerous reaction to heat exposure, characterized by a body
temperature usually above 40.6°C and central nervous system disturbances. The body
usually ceases to perspire.

Front 21

J wave

Back 21

ECG deflection found at the junction of the QRS complex and the ST segment. It is associated with hypothermia and seen at core temperatures below 32°C, most commonly in leads II and V6; also called an Osborn wave.

Front 22

superficial frostbite

Back 22

freezing involving only epidermal tissues resulting in redness followed by blanching and diminished sensation; also called frostnip.

Front 23

deep frostbite

Back 23

freezing involving epidermal and subcutaneous tissues resulting in a white appearance, hard (frozen) feeling on palpation, and loss of sensation.

Front 24

drowning

Back 24

asphyxiation resulting from submersion in liquid with death occurring within 24 hours of submersion.

Front 25

near-drowning

Back 25

an incident of potentially fatal submersion in liquid that did not result in death or in which death occurred more than 24 hours after submersion.

Front 26

mammalian diving reflex

Back 26

a complex cardiovascular reflex, resulting from submersion of
the face and nose in water, that constricts blood flow everywhere except to the brain.

Front 27

barotrauma

Back 27

injury caused by pressure within an enclosed space; when occurring during a diving descent is commonly called the squeeze.

Front 28

nitrogen narcosis

Back 28

a state of stupor that develops during deep dives due to nitrogen’s effect on cerebral function; also called “raptures of the deep.”

Front 29

decompression illness

Back 29

development of nitrogen bubbles within the tissues due to a rapid reduction of air pressure when a diver returns to the surface; also called “the bends.”

Front 30

pulmonary overpressure

Back 30

expansion of air held in the lungs during ascent. If not exhaled, the expanded air may cause injury to the lungs and surrounding structures.

Front 31

arterial gas embolism (AGE)

Back 31

an air bubble, or air embolism, that enters the circulatory system from a damaged lung.

Front 32

pneumomediastinum

Back 32

the presence of air in the mediastinum.

Front 33

recompression

Back 33

.resubmission of a person to a greater pressure so that gradual decompression can be achieved; often used in the treatment of diving emergencies.

Front 34

ionizing radiation

Back 34

electromagnetic radiation or particulate radiation that, by direct or secondary processes, ionizes materials that absorb the radiation. Ionizing radiation can penetrate the cells of living organisms, depositing an electrical charge within them. When sufficiently intense, this form of energy kills cells.

Front 35

half-life

Back 35

time required for half of the nuclei of a radioactive substance to lose activity by undergoing radioactive decay. In biology & pharmacology, the time required by the body to metabolize and inactivate half the amount of a substance taken in.

Front 36

beta radiation

Back 36

medium-strength radiation that is stopped with light clothing or the
uppermost layers of skin.

Front 37

alpha radiation

Back 37

low level form of nuclear radiation; a weak source of energy that is
stopped by clothing or the first layers of skin.

Front 38

denature

Back 38

alter the usual substance of something.

Front 39

zone of coagulation

Back 39

area in a burn nearest the heat source that suffers the most damage and is characterized by clotted blood and thrombosed blood vessels.

Front 40

zone of stasis

Back 40

area in a burn surrounding the zone of coagulation and that is characterized
by decreased blood flow.

Front 41

zone of hyperemia

Back 41

area peripheral to a burn that is characterized by increased blood
flow.

Front 42

emergent phase

Back 42

first stage of the burn process that is characterized by a catecholamine
release and painmediated reaction.

Front 43

fluid shift phase

Back 43

stage of the burn process in which there is a massive shift of fluid from
the intravascular to the extravascular space.

Front 44

intravascular space

Back 44

the volume contained by all the arteries, veins, capillaries, and other
components of the circulatory system.

Front 45

extravascular space

Back 45

the volume contained by all the cells (intracellular space) and the
spaces between the cells (interstitial space).

Front 46

hypermetabolic phase

Back 46

stage of the burn process in which there is increased body
metabolism in an attempt by the body to heal the burn.

Front 47

resolution phase

Back 47

final stage of the burn process in which scar tissue is laid down and the
healing process is completed.

Front 48

voltage

Back 48

the difference of electric potential between two points with different
concentrations of electrons.

Front 49

ohm

Back 49

basic unit for measuring the strength of electrical resistance.

Front 50

Ohm’s law .

Back 50

the physical law identifying that the current in an electrical circuit is directly proportional to the voltage and inversely proportional to the resistance

Front 51

Joule’s law

Back 51

principle identifying that the rate of heat production is directly proportional
to the resistance of the circuit and the square of the current.

Front 52

coagulation necrosis

Back 52

the process in which an acid, while destroying tissue, forms an
insoluble layer that limits further damage.

Front 53

liquefaction necrosis

Back 53

the process in which an alkali dissolves and liquefies tissue.

Front 54

ionization

Back 54

the process of changing a substance into separate charged particles (ions).

Front 55

rad

Back 55

basic unit of absorbed radiation dose.

Front 56

Gray

Back 56

a unit of absorbed radiation dose equal to 100 rads.

Front 57

superficial burn

Back 57

a burn that involves only the epidermis; characterized by reddening of the skin; also called a first-degree burn.

Front 58

partial thickness burn

Back 58

burn in which the epidermis is burned through and the dermis is damaged; characterized by redness and blistering; also called a second-degree burn.

Front 59

full thickness burn

Back 59

burn that damages all layers of the skin; characterized by areas that
are white and dry; also called third-degree burn.

Front 60

eschar

Back 60

hard, leathery product of a deep full thickness burn; it consists of dead and
denatured skin.