Chapter 7 Continued Flashcards
What happens if the master key gets hit?
It will die
True or false
there is a master key in every cell
true
Cell death without attempting to divide
Apoptosis (interphase death) or programmed cell death
Dies often one or more divisions
Mitotic or genetic ,death
Exposure as little as 0.1 gray just before not dividing on time
mitotic delay
temporary or repairing enzymes helping
interference with function
What has less dose than apoptosis
mitotic death
if there is a shoulder in the graph what does this mean?
can be repaired
if there is no shoulder in the graph what does this mean
cell death
-Radiation therapy
-dosage over time
-break into several equal parts (period of recovering)
Fractionation
(pulse in fluoro)
Small increments
-continuously amount of fluoro over time
protraction
is this lethal or survival
12 gray in 3 minutes
lethal
is this lethal or survival
12 gray over a couple of days
survival
Are white blood cells or nerve cells more sensitive?
white blood cells are more sensitive than nerve cells
Ionizing radiation adversely affects blood cells by depressing the number of active cells in the peripheral circulation. A whole-body dose of 0.25 Gyt delivered within a few days produces a measurable:
Hematologic Depression
Most blood cells are manufactured in the bone marrow. Radiation causes a decrease in the number of immature blood cells (stem or precursor) produced in the bone marrow and hence a reduction, ultimately, in the number of mature blood cells in the bloodstream. The higher the radiation dose received by the bone marrow, the higher will be the resulting cell depletion.
Depletion of immature blood cells
if the bone marrow cells have not been destroyed by exposure to ionizing radiation, they can repopulate after a period of recovery. The time necessary for recovery depends on the magnitude of the radiation dose received. If a relatively low dose (less than 1 Gyt) of radiation is received, bone marrow repopulation occurs within weeks after irradiation.
Repopulation after a period of recovery
blood forming center
Effects on stem cells of the hematopoietic system
Humans who receive whole-body doses above 5 Gyt may die within 30 to 60 days because of effects related to initial depletion of the stem cells of the hematopoietic system.
Whole-body doses in excess of 5 Gy
if there is an increase dose what happens to cell depletion and biological damage
both increased
true or false
bone marrow can repopulate if it wasnt destroyed
higher the dose the longer it takes to repopulate (to heal)
true
main form of oxygen throughout the body and help fight off infection
white blood cells
A dose of radiation higher than 0.5 Gyt lessens the number of platelets in the circulating blood, A dose of radiation in the range of 1 to 10 Gyt, will significantly deplete these cells, and it will take approximately 2 months for them to repopulate. During this period wound clotting will be highly compromised.
effects of ionizing radiation on thrombocytes
When significant numbers of lymphocytes are functionally damaged by radiation exposure, the body loses its natural ability to combat infection and becomes very susceptible to bacterial and viral antigens.
Effects of ionizing radiation on lymphocytes.
