Radiation Biology Flashcards

Vocabulary flashcards based on the Radiation Biology lecture notes.

Radiation Biology

The study of the effects of radiation on living tissue.

Ionizing Radiation

Radiation capable of changing the chemical state of matter, causing biological damage.

Non-ionizing Radiation

Radiation that bounces off or passes through matter without displacing electrons.

Alpha Particle

A type of radiation particle consisting of two protons and two neutrons; heaviest type of radiation particle.

Beta Particle

An electron that is not attached to an atom; has a small mass and a negative charge.

Neutron

A particle that doesn't have any charge and is present in the nucleus of an atom.

Electromagnetic Radiation

Radiation like X-rays and gamma rays; have no mass or charge and can penetrate through the body.

Radioisotopes

Radioactive isotopes of an element.

Radioactive Decay

The process of shedding excess particles and energy in the form of radiation by an unstable nucleus.

Half-life

The time it takes for half of the unstable atoms to undergo radioactive decay.

Natural Background Radiation

Radiation that comes from the sun, earth, and atmosphere.

Artificial Radiation

Man-made radiation, such as medical/dental x-rays and nuclear sources.

Direct Effects (Radiation Injury)

Radiation interacts directly with the atoms of the DNA molecule or another critical cellular component.

Indirect Effects (Radiation Injury)

Ionizing radiation breaks the bonds that hold the water molecule together, producing toxic substances.

Prodromal Period

The initial stage of radiation injury, characterized by nausea, vomiting, loss of appetite, and possibly diarrhea.

Latent Period

The time between exposure to radiation and the appearance of radiation damage.

Period of Injury

The stage of radiation injury where a variety of cell injuries may occur, such as cell death.

Recovery Period

The stage of radiation injury where some cellular injuries are repaired within the body's cells.

Dose Rate

How fast the radiation dose is received.

Cumulative Effect

The effects of radiation exposure are additive, and unrepaired damage builds up in tissues.

Somatic Effects

Radiation effects that occur in all cells of the body except the reproductive cells and are not passed to future generations.

Genetic Effects

Radiation effects that occur in reproductive cells and are passed along to future generations.

Mitotic Death

Cell death that occurs when cells die attempting to divide, primarily due to asymmetric chromosome anomalies.

Apoptosis

Programmed cell death characterized by a sequence of events resulting in cell separation in apoptotic bodies.

Bystander Effect

Cells directly affected by radiation release cytotoxic molecules, causing death in neighboring cells.

Single-Strand Breaks (DNA)

Breaks in the DNA that are of little biological consequence because they are easily repaired.

Double-Strand Breaks (DNA)

Breaks in the DNA believed to be the most important lesions produced in chromosomes by radiation.

Diagnostic Radiology

The use of x-rays to produce an anatomical or functional patient image for clinical use.

Mammography

An X-ray picture of the breast used to look for early signs of breast cancer.

Nuclear Medicine

The use of radioactive isotopes for diagnostic, treatment, and lab tests.

Radionuclide Angiogram

A test that can tell the doctor how well the heart pumps and how much blood is pumped with each heartbeat, using radioactive tracers.

Radiotherapy

The use of ionizing radiation to treat cancer and other conditions involving abnormal tissue growth.

Radiation Sterilization

The use of ionizing radiation to kill germs and neutralize other harmful organisms in medical devices.

Uranium

A naturally-occurring radioisotope.

Mutation

A change in DNA that can lead to the development of diseases including cancer (carcinogenesis).

Oncogenes

Genes that affect cancer incidence.

Ischemia

An area of heart muscle that has an inadequate blood supply.

Mitosis

The process of cell division. Cells are most sensitive to radiation during this phase.

Radicals

Toxic substances such as hydroxyl (OH) and superoxide anion (O2-) produced by ionizing radiation.

Tracer

A radioisotope that is taken orally, injected, or inhaled into the body to track its distribution.

DNA

The primary target for radiation; damage is caused by breaking bonds in the DNA.

Carcinogenesis

The development of cancer.

Gamma Rays

Electromagnetic radiation with high energy used in medical treatments.

X-rays

A form of ionizing radiation used for diagnostic imaging.

Tritium

A beta radiation emitting isotope produced by cosmic radiation in the atmosphere.

Carbon-14

A beta particle emitting isotope used in carbon-dating of fossils and other artifacts.

Nuclear Reactor

A facility used to produce radioisotopes.

Internal Organs Shielding

Dense materials like concrete and lead used to avoid exposing sensitive internal organs.

Cobalt-60

A radioisotope used to shrink the size of tumors and sterilize medical instruments.

Caesium-137

A radioisotope used to shrink the size of tumors within the bodies of cancer patients.

Atomic Nuclei

The central part of an atom, consisting of protons and neutrons.

Lymphoma

Cancers of the lymphatic system that can be treated with radiation therapy.

Leukemia

Cancers of the blood-forming cells that can be treated with radiation therapy.

Palliative Radiation Therapy

Radiation therapy given to help reduce symptoms such as pain from cancer.

Isotopes

Different forms of an element with the same number of protons but different numbers of neutrons.

M Phase

Mitosis phase - cells are most sensitive at or close to this phase.

G2 Phase

Phase in the mitotic cycle; usually as sensitive as M phase to radiation.

S Phase

Phase in the mitotic cycle; resistance to radiation is usually greatest in the later part.

G1 Phase

Phase in the mitotic cycle; can have a resistant period followed by a sensitive period.

Free Radicals

Highly reactive molecules with unpaired electrons, produced by radiation interaction with water.

Mitotic Cycle

The cycle of cell growth and division.

Germ Cells

Sperm and ova; mutations in these cells can be passed on as genetic abnormalities.

Sterility

Inability to reproduce; can be a short-term effect of high doses of radiation.

Cataracts

Clouding of the lens of the eye; can be a long-term effect of radiation.