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Chapter 8
Radiation Proctection
Question | Answer |
---|---|
The lethal dose of ionizing radiation for humans is what? | LD is 50/60 (50% for 60 days) |
Acute radiation syndrome occurs in 4 response stages what are they in order? | Prodromal, latent period, manifest illness, recovery or death |
What is the most radio sensitive vital organ system in the human body? | Hematopoietic |
When cells are exposed yo sublethal doses of ionizing radiation, approximately ___________ of radiation induced damage may be repaired over time, and about _______ is irreparable. | 90%, 10% |
The total radiation dose received by a somatic or genetic cell and the dose rate determines what? | Production of chromosome aberrations |
In 1898, after developing burns attributed to radiation exposure, this Boston dentist started investigating the hazards of radiation exposure and became the first advocate of radiation protection. Who is this person? | William Herbert Rollins |
As radiation dose increases, the severity of early deterministic effects does what? | Increases |
In the female, the ovarian stem cells does what? | Multiplies to millions of cells only during fetal development, before birth, and then steadily decline in number throughout life. |
What type of cells develop from a single precursor cell, the pluripotential stem cell? | 1. Lymphocytes/Granulocytes 2. Thrombocytes/erythrocytes 3. Platelets |
With regard to radiation exposure, which part of the GI tract is most severely affected? | Small Intestines |
A method of dose assesment in which biological markers or effects of radiation exposure are measured and the dose to the organism is inferred from previously established dose effects relationships. | Biological dosimetry |
Functions as an ongoing regeneration system for the human body; is relatively radiosensitive | Skin |
Whole body dose of ionizing radiation that can be lethal to 50% of an exposed population within 30 days | LD 50/30 |
Period during the menstrual cycle when a mature follicle releases an ovum | Ovulation |
Specialized, non dividing cells that are relatively radioresistant | Mature spermatogonia |
Middle layer of the skin | Dermis |
Form of ARS that occurs when humans receive whole body doses of ionizing radiation ranging from 1 to 10 Gy | Bone marrow syndrome |
Population inadvertently subjected to high levels of fallout during an atomic bomb test in 1954 | Marshall Islanders |
An abnormal decrease in white blood corpuscles, usually below 5000/mm | Leukopenia |
When radiation exposure causes the number of red blood cells, white cells, and platelets in the circulating blood to do | Decrease |
Alopecia (Hair loss) | Epilation |
Results when a organ or tissue fails to recover from radiation exposure | Necrosis, or death |
Form of ARS that results when the CNS and the cardiovascular system receive ionizing radiation doses of 50 Gy or more | Cerebrovascular syndrome |
Early somatic effects on organ systems that result from high doses of radiation | Deterministic effects |
Radiation sickness that occurs in humans after whole body dose of ionizing radiation delivered over a short amount of time | ARS |
Immature female germ cells | Oocytes |
Period of time when blood counts were the only means of radiation exposure monitoring for radiation workers engaged in radiologic practices | 1920's and 30's |
A single precursor cell from which all cells of the hematopoietic system develop | Pluripotential stem cells |
The 1st stage of ARS, which occurs within hours after a whole body absorbed dose of 1 Gy, or more; characterized by nausea, vomiting, diarrhea, fatigue, and leukopenia | Prodromal stage |
Form of ARS that appears at a threshold dose of approximately 6 Gy | Gastrointestinal Syndrome |
Following a period of about a week, during which non visible symptoms occur, symptoms again become visible during this stage of ARS | Manifest Illness |
Deviation from normal development or growth | Chromosome aberrations |
The priod after the initial stage of ARS during which no visible effects or symptoms of radiation exposure occurs | Latent period |
A decrease in the number of blood cells in the circulating blood can rsult in a lack of vitality and this condition | Anemia |
When biological effects from ionizing radiation demonstrate the existence of a threshold and the severity of the damage increases as a consequence of increased absorbed dose, the events are considered: | Deterministic |
Approximately what percent of the human body's surface skin cells is replaced daily by stem cells from an underlying basal layer? | 2% |
A cytogenetic analysis of chromosomes may be accomplished through the use of a chromosome map. What is this map called? | Karyotype |
During the age of 12-50, how many mature ova will a female produce? | 400 to 500 |
What are parts of the hematopoietic system? | 1.Bone marrow 2. Circulating blood 3. Lymphoid organs |
Many early radiologists and dentists developed a reddening of the skin caused by exposure to ionizing radiation. What is this condition called? | Radiodermatitis |
What measure of lethality may be a more relevant indicator of outcome for humans? | LD 50/60 |
What factors does somatic or genetic radiation induced damage depend? | 1.The amount of body area exposed 2. The quantity of ionizing radiation to which the subject is exposed 3. The specific parts of the body exposed |
In humans with the GI form of ARS, the part of the body most severely affected is the | Small intestine |
Following whole body reception of large doses of ionizing radiation delivered over a short period of time, what medical problems occurs in humans? | Acute radiation syndrome (ARS) |
The use of high level fluoro for extended periods of time can result in | Radiation induced skin injuries for patients |
What do the survivors of Hiroshima, Marshall Islanders, and Chernobyl have in common? | All were exposed to doses of ionizing radiation sufficient enough to cause ARS in many group members |
What does not cause early deterministic and somatic effects of radiation? | Doses encountered in diagnostic radiology |
What factors govern organ and tissue response to radiation exposure? | |
The hematopoietic, GI, and cerebrovascular syndrome are 3 separate dose related syndromes that are part of the: | Total body syndrome |
Without effective physical monitoring devices, what biological criteria would play an important role in the identification of radiation casualties during the first 2 days after a nuclear disaster | Nausea and vomiting |
Without medical support, the LD 50/30 for adult humans is estimated to be: | 3-4 Gy |
Infection, hemorrhage, and cardiovascular collapse are symptoms that can occur as part of ARS during the: | Manifest Illness |
What local tissue will experience consequences from high radiation doses? | 1. Bone marrow 2. Reproductive organs 3. Skin |
Imaging procedures usually result in: | Relatively low doses of gonadal radiation for the patient and for imaging personnel |
What are accessory structures of the skin? | 1. Hair follicles 2. Sebaceous glands 3. Sweat glands |
When cells are exposed to lethal doses of ionizing radiation, repair and recovery may occur because cells: | Contain a repair mechanism inherent in their biochemistry (repair enzymes) |
The testes of the human male and the ovaries of the female do not respond the same way to irradiation because? | Their is a difference in the way in which male and female germ cells are produced and progress |
When are human ovaries most sensitive? | During the fetal stages of life and during early childhood |
ARS is actually a collection of syndromes associated with: | Exposure to high levels of radiation |