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RADR 2213 Radiation Biology Test 2
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From where is CSF secreted? - correct answer ✔ Choroid Plexus Prodromal Period - correct answer ✔ the acute or immediate clinical symptoms that occur within hours of exposure and continue for up to a day or two What are some symptoms of the prodromal period? - correct answer ✔ Nausea, vomiting, diarrhea and white blood cell depletion Acute Radiation Syndrome - correct answer ✔ The sequence of events that follow high level radiation exposure leading to death within days or weeks Name the three types of acute radiation syndrome? - correct answer ✔ Hematologic death, (GI) Gastrointestinal death, (CNS) Central Nervous System death These cells are the first to respond after a significant amount of radiation has been delivered. - correct answer ✔ Lymphocyte cells
What amount of radiation is needed to cause permanent sterility? - correct answer ✔ 500 rad or 5 Gyt What is LD 50/60? - correct answer ✔ The dose of radiation to the whole body that cause 50% of irradiated subjects to die within 60 days If I radiate the whole body with a large amount of dose, this will cause half of the people to die in 60 days? - correct answer ✔ LD 50/ What does LD mean? - correct answer ✔ Lethal Dose What is Hematologic Syndrome? - correct answer ✔ a reduction in peripheral blood cells (red, white and platelets) after radiation exposure What is the Latent Period? - correct answer ✔ The time after exposure during which there is no sign of radiation sickness What is the Latent period often mistaken for? - correct answer ✔ It is mistaken for early recovery, but in reality it is the "well being". This misleading because it give not indication of the extensive radiation response yet to follow.
What is the dose-response relationship that will occur when human acute radiation lethality happens? - correct answer ✔ Non-Linear, threshold What is the mean survival time? - correct answer ✔ As the whole body radiation dose increases, the average time between exposure and death decrease. When death will occur. What is the relationship in mean survival time between dose and time? - correct answer ✔ As the radiation dose increase the mean survival time decreases. Deterministic Effect - correct answer ✔ Effects that occur minutes or days after the exposure to ionizing radiation What is the most devastating human response to radiation exposure?
- correct answer ✔ Death What type of radiation does not occur in diagnostic radiography and why? - correct answer ✔ Acute radiation lethality; it is of academic interest only because diagnostic x-ray beams are neither intense enough nor large enough to cause death
What groups of people were followed to determine the effects of acute radiation syndrome? - correct answer ✔ Chernobyl, Atomic bomb survivors, nuclear power meltdown (Japan) Acute radiation syndrome, severity and length are all dependent on_______ - correct answer ✔ Dose What is the time frame for the latent period? - correct answer ✔ The latent period is as short as a few hours or less, while at lower doses (100-500 rad) it can last several days or weeks What are the principal quantitative measures of human radiation lethality? - correct answer ✔ The dose necessary to produce a given syndrome and the mean survival time. What is the manifest illness? - correct answer ✔ The stage of acute radiation syndrome during which signs and symptoms are apparent characterized by possible vomiting, mild diarrhea, malaise, lethargy and fever What are the clinical signs and symptoms of Hematologic syndrome? - correct answer ✔ Nausea, vomiting, diarrhea anemia, leukopenia, hemorrhage, fever, infections,dehydrations. Recovery 2-4 weeks and up to 6 months,
Describe local tissue damage. - correct answer ✔ When only part of the body is irradiated, a higher dose is required to produce a response. All deterministic radiation response follows what type of dose response relationship and what does that mean. - correct answer ✔ Threshold type dose-response relationship. A minimum dose is necessary to produce a deterministic response. How much of your skin is renewed each day? - correct answer ✔ 2% per day What is the outer layer of the skin called? - correct answer ✔ epidermis The epidermis is made of several layers, what is the lowest layer of cells called? - correct answer ✔ Basal cells What type of cells are basal cells? - correct answer ✔ Stem cells What are stem cells? - correct answer ✔ Immature or precursor cells The earliest manifestation of radiation injury to the skin occur when?
- correct answer ✔ When the basal cells are damaged.
What type of x-ray does radiation therapy use? - correct answer ✔ Orthovoltage x-rays of 200-300 kVp. What is the main objective of radiation therapy? - correct answer ✔ To deposit energy in the tumor while sparing the surrounding normal tissue, this caused erythema and desquamation. Erythema - correct answer ✔ a sunburn-like reddening of the skin Desquamation - correct answer ✔ Ulceration and denudation of the skin Epilation - correct answer ✔ Loss of hair What is SED50? - correct answer ✔ Skin Erythema Dose: an analysis of person irradiated therapeutically with superficial x-rays show that the dose required to affect 50% of those irradiated. What is the required dose to get SED50? - correct answer ✔ 5gy or 500 rad - for SED 50
What is the minimum amount of radiation that will cause suppressed menstruation? - correct answer ✔ 10 rad or 100 mGyt After irradiation to the testes, a reduction in sperm would last how long? - correct answer ✔ It would be noticed for several weeks A male having been irradiated with 100 mGy or 10 rad should refrain from procreation for how long and why? - correct answer ✔ refrain fro 2-4 months, as this will help reduces genetic mutations changes in the stem cell What does the hemopoietic system consist of? - correct answer ✔ Bone marrow, circulation blood and lymphoid tissue (lymph nodes, spleen and thymus) What is the stem cell of the hempoietic system? - correct answer ✔ pluripotential stem cell: because it can develop into several different types of mature cells. What is the whole body dose to measure hematologic depression? - correct answer ✔ 250 mGyt or 25 rad Radiation exposure causes what hematologic effect? - correct answer ✔ decreased the number of all types of blood cell.
Define lymphopenia - correct answer ✔ reduction in lymphocytes Define granulocytosis. - correct answer ✔ rapid rise in granulocytes What are granulocytes? - correct answer ✔ scavenger type cells used to fight bacteria What are lymphocytes? - correct answer ✔ cells involved in the immune response Define granulocytopenia - correct answer ✔ reduction in granulocytes Define thrombocytopenia - correct answer ✔ depletion of platelets What are thrombocytes? - correct answer ✔ platelets involved in the clotting of blood to prevent hemorrahage Cytogenetics - correct answer ✔ study of the genetics of cells, particularly the cell chromosomes. What type of threshold dose response does chromosome aberrations follow? - correct answer ✔ Radiation induced chromosomes aberrations follow a non-threshold dose-response relationship.
What are diagnostic radiation protection guides based on? - correct answer ✔ Based on stochastic effects and linear non-threshold dose response relationship What is the difference between deterministic and stochastic effects? - correct answer ✔ Stochastic has a low LET and in linear non-threshold; deterministic is non-linear threshold. How are stochastic effects exhibited? - correct answer ✔ Exhibit an increasing incidence of response, to severity, with increasing dose. What are the two principle stochastic effects of radiation? - correct answer ✔ Radiation induced malignancy and genetic effects What are the late effects of skin irradiation? - correct answer ✔ Erythema, desquamation, Late developing, carcinoma, radiodermatitis What is dermatitis? - correct answer ✔ Callused, discolored, weathered appearance to the skin, very tight, brittle and sometimes flake or crack. What is the stochastic response to irradiation of blood forming organs? - correct answer ✔ Leukemia
Damage to the lymphocytes are both __________________. - correct answer ✔ Deterministic and stochastic What are cataracts? - correct answer ✔ Complete or partial opacity of the optic lens What group of people had a stochastic effect of cataracts? - correct answer ✔ Early Cyclotron Workers Why were the cyclotron workers affected with cataracts? - correct answer ✔ Those who manually focused an electron beam were exposed to high levels of exposure to the lens of the eyes What is the average latent period for radiation induced cataracts? - correct answer ✔ Approximately 15 years Which group is likely to have the lens of the eyes affected (older or younger)and why? - correct answer ✔ Older individuals, because their eyes are more sensitive to the radiation What is the threshold after an acute x-ray exposure, that cause cataracts? - correct answer ✔ The acute threshold for cataracts is 200 rad or 2 Gyt.
Describe Relative Risk. - correct answer ✔ It compares the number of people exposed with symptoms to those with symptoms but never exposed. Even though the late effects of radiation exposure are easy to observe, it is very difficult to relate that back to a specific exposure. Describe Excess Risk. - correct answer ✔ The difference between the observed number o cases and the number o cases that usually occur. Describe Absolute risk. - correct answer ✔ Assumes a linear dose response relationship and relies on knowing the number of cases and the radiation dose. What type of dose response relationship does leukemia follow? - correct answer ✔ Linear non-threshold dose response relationship. What is the most frequently observed radiation induced cancer? - correct answer ✔ Leukemia What groups of people were affected with leukemia as a result of radiation induced malignancies? - correct answer ✔ Atomic bomb survivor, early American radiologists, and those with Ankylosing Spondylitis What is the latent period for radiation induced leukemia? - correct answer ✔ 4 -7 years
What group of people were affected with thyroid cancer as a result of radiation induce malignancy? - correct answer ✔ Children of the Marshall Islands, Children treat for enlarged thymus, and atomic bomb survivors who were children at the time of exposure. What is the latent period for radiation induced thyroid tumor or cancer? - correct answer ✔ The latent periods for benign cases are between 5 - 35 years and 10 - 35 years for malignant cancers Are all radiation induced thyroid tumors cancerous? - correct answer ✔ No, some can be benign or malignant What are the risk for women to get radiation induced thyroid cancer?
- correct answer ✔ Women have a 3 - 5 times greater risk due to hormonal influences What group of people were affected with radiation induced bone cancer? - correct answer ✔ Radium watch dial painters, patients who were treated with radium salts Those who developed skin cancer, preceded what type of effects? - correct answer ✔ Preceded by radio-dermatitis
What is the name of the committee that study the effects if ionizing radiation? - correct answer ✔ BEIR Committee (The committee on the Biological Effects of Ionizing Radiation) What does the BEIR Committee study? - correct answer ✔ They study the late effects of low-dose radiation and doses of radiation over 1 rad/year Does BEIR override ALARA Compliance? - correct answer ✔ No, It must maintain ALARA Compliance What type of radiation does not impair fertility? - correct answer ✔ Low-dose chronic irradiation What is the most radiation sensitive period during pregnancy? - correct answer ✔ the first trimester What are the radiation in utero effects based on? - correct answer ✔ dose and time Why is the major organogenesis (weeks 2-10) the most sensitive? - correct answer ✔ It is when all the major organs of the body are being formed
Spontaneous abortion occurs as a result of fetal irradiation during what time period? - correct answer ✔ 0 - 14 days What type of effects occur to the fetus of 2-10 weeks gestation when irradiated? - correct answer ✔ Congenital, skeletal or organ abnormalities may occur What type of effects occur to the fetus of 2-15 weeks gestation when irradiated? - correct answer ✔ Mental retardation What type of effects occur to the fetus at 0-9 months gestation when irradiated? - correct answer ✔ Childhood malignant disease, neonatal death, impaired growth and development, genetic mutations What dose amount will cause risk to gonadal cells? - correct answer ✔ Any dose of radiation to gonadal cell carries some risk. What type of dose response relationship does genetic effects follow? - correct answer ✔ Genetic effects follow a linear, non-threshold dose response relationship How are most radiation induced mutations described and when is it noticed? - correct answer ✔ Recessive, meaning that the required mutant gene must be present in both the male and female to produce the trait; thus it may not be noticed for several generations.
