Chapter 8 Flashcards
Biological damage sustained by living organisms as a consequence of exposure to ionizing radiation
Somatic Effects
Deterministic somatic effects were formerly called:
Nonstochastic somatic effects
Consequences of early somatic effects are:
Cell killing
Early somatic effects are _______ related to the dose received
Directly
Are early somatic effects threshold or nonthreshold?
Threshold - there is a point at which they begin to appear
2 types of late radiation effects
Deterministic somatic
Stochastic
Late radiation effects are consequences of
High level radiation expsorure or low doses over a long interval of time
Appears within minutes, hours, day, or weeks of the time of radiation expsorue
Early deterministic somatic effects
What are early deterministic somatic effects
Nausea
Fatigue
Erythema
Epilation
Blood disorders
Intestinal disorders
Fever
Dry and moist desquamation
Depressed sperm count
Temporary or permanent sterility in male or female
Injury to the central nervous system
What is the whole-body dose that can result in early deterministic effects
6 Gyt
When does ARS occur
Occurs after whole-body reception of large doses of ionizing radiation delivered over a short period of time
Data from studies of population exposed to doses of ionizing radiation sufficient to cause ARS have been obtained from
Atomtic bomb survivors of Hiroshima and Nagasaki
Marshall islanders - atomic bomb test in 1954
Accident victims from Chernobyl
Radiation therapy patients
What are 3 dose-related syndromes of ARS
Hematopoietic (bone marrow)
Gastrointestinal
Cerebrovascular
When does Hematopoietic syndome occur
From 1-10 Gyt
When does Gastrointestinal syndrome occur
Appears at 6 Gyt and peaks after 10 Gyt
When does cerebrovascular sydrome occur
50 Gyt or more
Stages of ARS
Prodromal
Latent
Manifest illness
Death or Recovery
Average survival time of hematopoietic syndrome
6-8 weeks
Symptoms of hematopoietic sydrome
Decrease in number of red blood cells, white blood cells, and platelets
Symptoms of gastrointestinal syndrome
Loss of appetite, anemia, leukopenia, hemorrhage, infection, electrolytic inbalance and emaciation
Survival time of cerebrovascular syndrome
Several hours - 2 to 3 days
Symptoms of cerebrovascular sydrome
Excessive nervousness, confusion, lack of coordination, loss of vision, burning sensation of the skin, loss of consciouness, disorientation, shock, meningitis, respitory distress, coma
Location of Chernobyl power plant accident
Soviet Union
Date of Chernobyl power plant accident
4/26/1986
Whole-body doses of ionizing radiation received from Chernobyl power plant accient
6 Gyt
What is LD 50/30
Whole body dose of radiation that can be lethal to 50% of the exposed population within 30 days
The LD 50/30 for adult humans is
3-4 Gy
In the repair of sublethal damage, which cells have a better prospect for recovery and why
Oxygentated cells - receive more nutrients
Appox ___% of radiation damage is irreparable
10%
A ________ response in biologic tissue can occur when any part of the body receives a high radiation dose
Destructive
Significant cell death from substantial exposure leads to _______ of organs and tissues
Atrophy
Organ and tissue response to radiation exposure depends on
Radiosensitivity
Reproductive characteristics
Growth Rate
Three layers of the skin
Epidermis (outer)
Dermis (middle)
Hypodermis (subcutaneous)
Accessory structures of the skin
Hair follicles
Sensory receptors
Sebaceous glands
Sweat glands
What is epilation
Loss of hair
Ionizing radiation treats skin dieseases such as
Ringworm
Dose that can depress that male sperm population or cause a genetic mutation in future generations
.1 Gy
Gonadal dose that may delay or suppress menstration
.1 Gy
Gonadal dose that will cause temporary sterility
2 Gyt
Gonadal dose that will cause permanent sterility
5 Gyt
What is the whole body dose that produces a hematologist depression?
.25 Gyt
What does the hematopoietic system consist of
Bone marrow
Circulating blood
Lympoid organs
Cells of the hematopoietic system develop from a single precursor cell called the
Pluripotential stem cell
Pluripotential stem cells are the primary cells of:
Lymphocytes
Neutrophils
Granulocytes
Thrombocytes (platelets)
Erythrocytes
The study of cell genetics with emphasis on cell chromosomes
Cytogenesis
A cytogenetic analysis of chromosomes may be accompished through the use of a chromosome map called a :
Karyotype
__________ is the phase of cell division in which chromosome damage caused by radiation exposure can be evaluated
Metaphase
Somatic and Genetic Damage Factors
Quantity of ionizing radiation
Ability of ionizing radiation to cause ionization of human tissue
Amount of body area exposed
Specific body parts exposed
What does somatic mean?
Body (all non reproductive cells)
Type of curve the represents deterministic somatic effects
Nonlinear threshold
How does an increase in dose effect stochastic effects
Increases probability but not severity
Average survival time of gastrointestinal syndrome
3-10 days
Effects of ionizing radiation on the skin
Radiodermititis
Desquamation
Which part of the gastrointestinal tract is most severely affected by radiation
Small intestine
The total radiation dose given to a somatic or genetic cell and the period of time in which that does was delivered determine the rate of production of
Cell aberrations
A Boston dentist who became the first advocate of radiation protection
William Herbert Rollins
