chapter 8 EXAM 4 Flashcards
somatic effects
biologic damage experienced by living organisms as a result of exposure to radiation
the somatic effects are classified as either
late somatic effects
early somatic effects
early somatic effects
effects of ionizing radiation that appear within minutes, hours, days, or weeks of high doses
early somatic effects are also called
acute effects
late somatic effects
non genetic effects that appear months or years following exposure to ionizing radiation
4 somatic and genetic damage factors
- quantity of ionizing radiation
- ability of the ionizing radiation to cause ionization
- amount of body area exposed
- the specific body parts exposed
true or false
ionizing radiation produces the greatest amount of biologic damage in the human body when a large dose of densely ionizing radiation is delivered to a large or radiosensitive area of the body
true
deterministic somatic effects
if the consequences of irradiation include cell killing and are directly related to the dose received
what were deterministic somatic effects formerly called
nonstochastic somatic effects
early deterministic somatic effects depending on the exposure will appear within
minutes, days, hours, or weeks
t or f
the severity of the early deterministic somatic effects is dose related
true
early deterministic somatic effects
high dose effects include
nausea fatigue erythema epilation (loss of hair) blood disorders dry and moist desquamation (shedding of skin) depressed sperm count injury to CNS
acute radiation syndrome ARS
occurs in humans after whole body reception of large doses of ionizing radiation delivered over a short period of time
probs from a nuclear powerplant explosion
four stages of clinical signs and symptoms of ARS
- prodromal stage
- latent period
- manifest illness (acute stage)
a. hematologic (hematopoietic) syndrome
b. gastrointestinal syndrome
c. CNS (cerebrovascular or neurovascular syndrome) - death (or recovery, in little dose)
- prodromal stage
the immediate response of ARS
severity of symptoms is dose related
prodromal stage may last from a few hours to
a couple of days
what is the immediate response of the prodromal stage
sickness
individuals who are exposed to radiation levels greater than 1 Gyt dose to the whole body usually show prodromal symptoms which include
nausea, vomiting, diarrhea, and a reduction in the white blood cells of circulating blood
t or f
the time between the exposure and the onset of prodromal symptoms is an indication of the magnitude of the exposure
true
the prodromal stage is also called
NVD syndrome (nausea, vomiting, diarrhea)
- latent period
period of “well being”
no clinical symptoms or illness
t or f
the latent period is sometimes mistakenly thought to indicate an early recovery from a moderate radiation dose
true
the latent period can extend from
a few hours (at doses in excess to 50 Gyt) or less, to weeks (at doses from 1-5 Gyt)
the higher the dose in the latent period,
the shorter the latent period
- MANIFEST ILLNESS (ACUTE STAGE)
the full clinical effects are evident
a dose related period characterized by 3 syndromes
what are the 3 syndromes that become manifest during this manifest ilness stage
- hematologic (hemapoetic) syndrome
- gastrointestinal syndrome
- CNS (cerebrovascular, neurovascular syndrome
the hematopoietic syndrome (hematologic syndrome) or bone marrow syndrome occurs when humans receive a whole body does of ionizing radiation ranging from
1 to 10 Gy (100-1000 rad)
what happens in the prodromal stage of the hematopoietic syndrome (hematologic syndrom) (bone marrow syndrome)
nausea and vomiting
what happens and how long is the Latent period of hematopoietic syndrome (hematologic syndrome) (bone marrow syndrome)
can extend as long as 4 weeks
no sign of illness, but the # of cells in circulating blood are declining during this time
what happens in the manifest illness stage of the hematopoietic syndrome (hematologic syndrome) (bone marrow syndrome)
reduction of all blood cell counts
anemia and hemorrhage
serious infections
at lower limits of the dose range 100 to 200 rad(1-2 Gyt) in the manifest illness of the hematopoietic syndrome
bone marrow cells will repopulate the marrow to support life in the majority of individuals
will recover 3 weeks to 6 months after irradiation
after an exposure of 200 rad (2 Gyt) in the hematopoietic syndrome
a few sensitive individuals may die 6-8 weeks after an exposure
the primary cause of death in the hematopoetic syndrome is
a destruction of bone marrow
the gastrointestinal syndrome occurs when humans receive whole body doses ionizing radiation ranging from
600 rad - 1000 rad (6Gy-10Gy)
without receiving medical support persons receiving doses of 6-10 Gy may die in how many days
3-10 days following exposure
prodromal stage of the Gastrointestinal syndrome occurs within? and causes what?
occurs within a few hours
causes severe nausea and vomiting accompanied by cramps and diarrhea
latent period of the gastrointestinal syndrome can last
as long as 5 days
signs and symptoms that may occur in the manifest illness stage of the gastrointestinal syndrome
fever fatigue loss of appetite lethargy anemia leukopenia hemorrhage infection electolyte imbalance
death from gastrointestinal syndrome occurs primarily because
of damage to epithelial cells lining the GI tract
what part of the GI tract is most severly affected in the manifest illness stage of the Gastrointestinal syndrome
the small intestine
because of the breakdown of epithelial cells
CNS syndrome occurs when the central nervous system and cardiovascular system receive doses of
50 Gyt or more
signs and symptoms of the prodromal stage of the CNS syndrome
excessive nervousness confusion severe nausea vomiting, diarrhea loss of vision burning sensation of the skin loss of consciousness
how long does the latent period of CNS syndrome last
up to 12 hours
signs and symptoms of the manifest illness stage of the CNS syndrome
prodromal symptoms come back with increased severity
death in the CNS syndrome may be due to
increased pressure in the confining cranial vault as a result of increased fluid content
lethal dose 50/30
signifies the whole body dose of radiation that can be lethal to 50% of the exposed population within 30 days
LD 50/30 for adult humans is estimated to be
3-4 GYt (300-400rad) without medical support
whole body doses greater than what may cause death to the entire population in 30 days without medical support
6 Gyt (600 rad)
with medical support humans have tolerated doses as high as
8.5 Gyt (850 Rad)
regardless of treatment, whole body equivalent doses of greater than what are fatal
12 Gyt (1200rad)
do organs with oxygenated cells recover better than hypoxic cells
yes
approximately how much percent of radiation induced damage may be repaired overtime?
90% leaving 10% irreparable
organ and tissue response to radiation exposure depends on
radiosensitivity
reproductive characteristics
growth rate
examples of tissues that suffer immediate consequences from high radiation doses
skin
male/female reproductive organs
bone marrow
radiodermititis
reddening of the skin caused by exposure to ionizing radiation
leads to cancerous lesions on hands and fingers
william herbert rollins was a
boston dentist who suffered severe burns on hands and fingers
william herbert rollins is known as the first
advocate of radiation protection
3 layers of skin
- epidermis
- dermis
- hypodermis
a single absorbed dose of what can cause skin erythema within 24-48 hrs after irradiation
a dose of 2 Gy (200 rad)
desquamation
shedding of outer layer of skin
epilation or alopecia
hair loss
in the past skin diseases such as ring worm were treated and cured by irradiation of the affected area with
grenz rays (xrays in energy range of 10-20 kVp)
doses as low as what are capable of depressing male sperm population and has the potential to cause genetic mutations in future generations
doses as low as 0.1 Gy (10rad)
a gonadal dose of what may delay or supress menstruation in the female
doses of 0.1 Gy (10rad)
a dose of what in male testes and female ovaries may lead to temporary sterility
2 GYt (200rad)
a dose of what in testes and ovaries may lead to permanent sterility
5-6 Gyt (500-600rad)
genetic mutations have been produced in experimental animals when their ovaries were irradiated with doses as low as
.25 Gyt (25rad)
a whole body dose of what would produce a measurable hematologic depression
0.25 Gy (25rad)
cells of the hematopoietic system all develop from a single precursor cell called
pluripotential stem cell
lymphocytes
white blood cells that play an active role in producing immunity for the body
granulocytes
white blood cells that act as scavengers to fight bacteria
thrombocytes
platelets
blood cells that initiate blood clotting and prevent hemorrhage
erythrocytes
red blood cells that carry oxygen from the lungs to all body tissue and cells as blood circulates
life span of lymphocytes
a few hours
Life span of erythrocytes
almost 120 days
a radiation dose as low as what can cause a decrease of lymphocytes in the bloood
a dose as low as 0.1 Gy (10rad)
a dose of what will cause a decrease in neutrophils
a dose of 0.5 Gy (50rad)
a dose greater than what can cause a decrease in the number of thrombocytes
a dose greater than 0.5 Gy (50rad)
a measurable hematologic depression can be caused by a whole body dose of radiation as low as
0.25 Gy (25rad)
cytogenetics
study of cell genetics with emphasis on cell chromosomes
karyotype
cytogenic analysis of chromosomes through the use of a chromosome map
chromosome damage caused by radiation can be evaluated during what stage of mitosis
metaphase
