Chapter 4 Extra Flashcards
define syndrome
- is used to show the relationship of the signs and symptoms to a specific type of trauma or disease process.
What radiation exposures must happen I order for total body radiation syndrome to be applicable?
- an organ must be exposed acutely (in seconds or minutes)
- there must be exposure of the total body area
- external penetrating sources, for example, X-rays, gamma-rays, and neutrons, produce the radiation syndromes.
define total body radiation syndrome
- the response of an organism to whole body radiation results in specific findings
what are consequences of acute radiation exposure?
- short-ending life span
- dose dependent
- can be very fatal
define LD 50/30
- lethal dose to kill 50% of a population in 30 days
define LD 50/60
- lethal dose to kill 50% of a population in 60 days
what happens when dose increase?
- survival time and number of survivors decrease
what are the 3 different types of Acute Radiation Syndrome?
- Bone Marrow
- Gastrointestinal (GI)
- Central Nervous System (CNS)
define bone marrow syndrome
- hemopoietic (development of blood cells)
damage - occurs within 100-1,000 R range
- death occurs between 6-8 weeks
- no one survives 1,000 R
- destruction of bone marrow -> decline production of RBC’s, WBC’s, and platelets
- death results from anemia and infection
^ body becomes very vulnerable from lack of protection
define gastrointestinal (GI) syndrome
- damage in the gastrointestinal tract, especially the small intestine
- occurs with 600-10,00 R range
- not dose-dependent
- death happens at the same time regardless of dose
- death occurs 3-10 days w/o help, 2 weeks w/ help
- damage to villi cells creates a decline of absorption in the GI tract
- dehydration
- systemic infections
- decline of WBC’s
Death:
- infection
- dehydration
- electrolyte balance
define the Central Nervous System (CNS) syndrome
- occurs in doses greater than 10.000 R
- death is within hours
- damage to blood vessels
- edema (swelling)
- vasculitis (inflammation of blood cells)
- meningitis (inflammation of spinal cord and brain membranes)
- person does not live long enough to show symptoms
what are the 4 different types of response stages?
- Prodromal
- Latent
- Manifest
- Death or Recovery
define prodromal stage
- NVD (nausea, vomiting, and diarrhea)
- occurs with low doses of 50 rads
- lasts a few minutes to days
- dose dependent (the higher the dose, the shorter the stage)
define dose dependent
- the higher the dose, the lower the stage
define the latent stage
- asymptomatic
- changes that can lead to recovery or death
- dose dependent
- weeks below 500 R -> hours/less than 10,00 R
define the manifest stage
- lasts minutes to weeks
- the animal is noticeably ill and shows signs and symptoms
What are the response stages in bone marrow syndrome?
Prodromal
- involves NVD
- few hours after exposure
Latent
- bone marrow stem cells are dying
- reduction of cells circulating the blood
Manifest
- reduction of cell count
- depression of blood cell count (cytopenia)
- causes anemia and infection
- leads to decline of blood cells and can lead to hemorrhage
what are the response stages in the gastrointestinal (GI) syndrome?
prodromal
- happens within hours
- NVD
- cramps
Latent
- occurs on the 5th day
- NVD occurs again
fever
Manifest
- 5th to 10th day
- GI tract, especially the small intestine is damages by doses in radiation
- death occurs from dehydration, infection, and electrolyte imbalance
define Crypts of Lieberkuhn
- radiosensitive cells that are precursor to the population of villi cells
- in the GI tract
what are the response stages in the Central Nervous System (CNS) syndrome?
prodromal
- NVD
- confusion
- loss of consciousness
- burning sensation of the skin
Latent
- lasts several hours
Manifest
- 5-6 hours
- results in diarrhea, convulsions, coma and death
- person dies due to the damage of blood vessels
define atrophy
- shrinking of the tissue or organ
define local tissue damage
- atrophy may occur
- leads to an organ or tissue to not function properly
- tissue response depends on radiosensitivity, reproduction, and maturation rates
- Ex.) skin, eyes, gonads
define skin tissue damage
- inflammation
- erythema (100-10,000 rads)
- desquamation
- basal layer cells are radiosensitive
- with moderate doses, skin can regenerate
- with high doses, it can lead to atrophy, fibrosis, pigment changes, etc.
define SED
- skin erythema dose
- the necessary amount of SED to affect 50% of the people is approx. 600 rads (6 Gy)*
what dose -response relationship does skin erythema have?
- nonlinear; threshold
are hair follicles radiosensitive or radioresistant?
- radiosensitive
- since they’re growing tissues, they’re radiosensitive
- moderate dose = temporary alopecia/epilation
- high dose = permanent epilation
define radiation cataractogenesis
- formation of cataracts by radiation
whats the dose-response relationship for eyes?
- threshold; nonlinear
what are some precautions with gonads?
- they are highly radiosensitive
- doses as low as 10 rad can cause observable responses
define mature depletion
- damage and reduction in the number of spermatogonia, leading to the depletion of mature sperm
