biology

28問 • 1年前

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branch of biology concerned with the effects of ionizing radiation on living systems.

Radiobiology

Artificial (Man-made)

Accounts for about 15% of the total radiation burden, 97% of all man-made radiation is due to diagnostic medical (and dental) exposures

Natural Sources

Cosmic, Terrestrial, Internal

Comes from the sun and outer space and consists of positively charged particles, as well as gamma radiation.

Cosmic radiation

Terrestrial Radiation

Natural sources of radiation in the ground, rocks, building materials and drinking water supplies., some of the contributors to terrestrial sources are natural radium, uranium and thorium.

Internal Radiation

Our bodies also contain natural radionuclides., Potassium 40 is one example.

Artificial Sources

Dental and other medical X-rays, Radiation used to diagnose diseases and for cancer therapy, industrial uses of nuclear techniques, Consumer products such as luminous wrist watches, ionization smoke detectors, Small amounts released from coal and nuclear power plants

1895

Wilhelm Conrad Roentgen announces discovery of X-rays

1896

(4 months later) Reports of skin effects in x-ray researchers

1902

First cases of radiation induced skin cancer reported

1906

Pattern for differential radiosensitivity of tissues was discovered.

Wilhelm Conrad Roentgen

(1845 - 1923), 1895- discovered x-rays, He received the first Nobel Prize for physics in 1901.

cells are killed easily by radiation 5

Radiosensitive

cells are not affected by high doses of ionizing radiation

Radioresistant

By 1906, Bergonie and Tribondeau realized that cells were most sensitive to radiation when they are:

Rapidly dividing, Undifferentiated, greater the mitotic activity

The primary damage to mature bone results from ______-induced damage to the vasculature of the periosteum and cortical bone, which are normally already sparse

radiation

3 types of radiation caries:

Superficial lesions attacking buccal, occlusal, incisal, and palatal surface- most common, Caries involving primarily the cementum and dentin in the cervical region- lesions may progress around the teeth circumferentially and result in loss of the crown, Dark pigmentation of the entire crown- the incisal edges may be markedly worn

The best method of reducing radiation caries

daily application for 5 minutes of a viscous topical 1% neutral sodium fluoride gel

osteoradionecrosis

cause: high doses of ionizing radiation, bone decay because of radiation

MRONJ: Medication Related OsteoNecrosis of the Jaw

Cause: medication being taken by the patient, Most common drug is bisphosphonates (given to patients who are undergoing chemotherapy and to those who have osteoporosis)

Wharton’s duct à mixed but predominantly serous

Sublingual

has the power to create charged ions by displacing electrons in atoms

ionizing radiation

Has the capacity to change the posture of atoms but not alter their structure, composition, and properties Excitation

Non-ionizing radiation

Non ionizing

powelines, radio and television, microwave, infrared, uv

Ionizing

x rays, gamma rays

Effects including radiation sickness and radiation burns, seen immediately after large doses of radiation delivered over short periods of time

Acute effects:

DETERMINISTIC EFFECT

Expecting that a patient would have this kind of side effect from the radiation, you are expecting that a radiotech has a cataract because he is exposed to radiation, Dose above the threshold determines occurrence, Effects such as nausea, reddening of the skin or in severe cases, more acute syndromes that are clinically expressed in exposed individuals within a short period of time after exposure to radiation at high doses, mainly cell death and delayed cell division, caused by exposure to high levels of radiation

TASTE BUDS

Patients often notice a loss of taste buds acuity during the second or third week of radiotherapy., sensitive to radiation, Taste loss is reversible and recovery takes 60-120 days.

Sporeformers

Tameyra Stefani Al-Suhairy · 44問 · 1年前

Sporeformers