Shared Flashcard Set

Details

rad bio and protection
test review for dec. 14 test
142
Science
Graduate
12/13/2009

Additional Science Flashcards

 


 

Cards

Term
in the living organism
Definition
in vivo
Term
in cultured cells in the labaratory
Definition
in vitro
Term
cells from tumors and many normal tissues will grow and form colonies ...
Definition
in vitro
Term
studies can be done on synchronous and asynchronous __
Definition
cell populations
Term
initial radiation done on these to see how radiation effects cells
Definition
HeLa cells
Term
what happens to cells after irradiation?
Definition

division delay

interphase death

reproductive failure

 

Term
:at any one time cells in tissues are at different phases of mitosis
Definition
division delay
Term
: ratio of # of cells in mitosis to # cells in population of cells
Definition
mitotic index
Term
___ % of cells are in ____ at any one time
Definition
1-2 , mitosis
Term
when cells are irradiated the ____ is disturbed 
Definition
constant ratio (mitotic index)
Term
cells in mitosis complete the division, but cells about to enter mitosis are delayed in ___
Definition
G2
Term
when cells are delayed in G2, the mitotic index ______
Definition
decreases
Term
if dose is low enough, cells ...
Definition
recover and proceed through mitosis
Term
when cells recover and proceed through mitosis, this ____ the mitotic index, called __________
Definition
increases, mitotic overshoot
Term
at lower doses (0.5 Gy) , cells return to mitotic index of '___'
Definition
pre-irradiation
Term
At high doses (10 Gy), the length and magnitude of delay was increased and no mitotic overshoot was observed- cells died before mitosis ( __ )
Definition
interphase death
Term
hopefully for extra credit, the theories why there is division delay :
Definition

* chemicals needed for division are altered by radation

*protein aren't synthesized.

*DNA synthesis does not progress at the same time.

Term
:death of cells before they enter mitosis
Definition
interphase death
Term
dose for interphase death to occur is dependent on the __ and ___
Definition
cell type and degree of differentiation
Term
:possibly caused by chemical changes in the cell which causes decreases in energy production. 
Definition
Interphase death
Term
:decrease the amount of cells after radiation that are able to reproduce
Definition
reproductive failure
Term
: inability of cells to go through repeated divisions.
Definition
reproductive failure
Term
: there are some hits in all targets 
Definition

lethal damage

 

Term
:there are some hits in few targets
Definition
sublethal damage
Term
: no hits to targets
Definition
no damage
Term

____ after irradiation can influence the proportion of cells that can survive. 

(potentially lethal damage PLD)

Definition
environmental conditions
Term
if cells do not attempt division because of the cell condition, there is more time for radiation damage...
Definition
to be repaired
Term
____ does not occur when cells are rapidly dividing and after exposure to high LET
Definition
PLD
Term
Damage must be ____ before a lethal effect becomes evident.
Definition
accumulated
Term
The molecular basis of ___ is not fully understood.
Definition
SLD sublethal damage
Term
the repair of sublethal damage is studied by comparing the effects of __ to __
Definition
single dose to fractionated dose
Term
Division delay is __ dependent.
Definition
dose
Term
mitotic overshoot shows the ability of the cells to overcome ..
Definition
the delay
Term
radiation can act as a _______
Definition
synchronizing agent
Term
; the damage that is influenced by post irradiation conditions
Definition
PLD
Term
: repair is shown by the increase in survival when a dose of radiation is fractionated.
Definition
SLD
Term
When dose rate is reduced, there is a reduction in cell killing becuase ___ repair occurs
Definition
SLD
Term
single target/single hit :
Definition
cell is most radiosensitive
Term
single target/multiple hit : 
Definition
not easily damaged
Term
multiple target/multiple hit :
Definition
most radioresistant
Term
Cell survival curves: in order to study the radiosensitivity of cells, researchers irradiate cells and then count 
Definition
the number of cells surviving per dose
Term
cell survival curves can be counted ____ and ___
Definition
both in vitro and now in vivo
Term

Law of Bergonie and Tribondeau

Sensitivity is directly proportional to the ___.

Definition
mitotic activity
Term

Law of bergonie and tribondeau

Sensitivity is indirectly proportional to the _____. 

Definition
differentiation
Term
Greater mitotic activity= 
Definition
more sensitive
Term
more differentiated = 
Definition
less sensitive
Term
: less likely to react, or less sensitive, to a radiation dose
Definition
radioresistant
Term
cell damage is influenced by 
Definition
biological stress on the cell
Term
the greatest stress on the cell is
Definition
mitosis
Term
biological stress on a cell is exposed when?
Definition
pre and post irradiation
Term
cell damage is similar to biological stress, but is expressed only at ___,so rapidly dividing cells show damage sooner and appear more sensitive.
Definition
mitosis
Term
A differentiated cell is one that has ______
Definition
specialized function and/or structure
Term
An undifferentiated or immature cell's primary function is to ____to maintain its own population and to replace mature cells
Definition
divide
Term

spermatogonia --->

 

Definition
spermatocyte
Term
spermatocyte--->
Definition
spermatid
Term
spermatid--->
Definition
sperm
Term
: this means the vulnerability of cells to damage by radiation
Definition
radiosensitivity
Term
different cells have different sensitivities depending on their ...
Definition
growth rates
Term
___ are more radioresistant
Definition
mature cells
Term
_______ are more radiosensitive
Definition
immature cells
Term
what are the 3 general cell populations?
Definition

stem cell populations

transit cell populations

static populations

Term
:one whose sole purpose is to divide
Definition
stem cell
Term
stem cells maintain..
Definition
their own populations
Term
stem cells produce
Definition
cells for another population
Term
stem cells are _____ , and also are _______
Definition
undifferentiated and radiosensitive
Term
transit cells are
Definition
cells on their way from stem cell compartments to end cell compartments
Term
transit cells May or May not
Definition
divide
Term
static population cells are 
Definition
differentiated
Term
static populations show little or no
Definition
mitotic activity
Term
what are the four cell population categories of Rubin and Casarett
Definition

-vegetative intermitotic VIM

-differentiating inter mitotic DIM

-Reverting post mitotic RPM

-fixed post mitotic 

Term

VIM- divide?

differentiation?

radiosensitivity?

 

Definition

rapidly dividing

undifferentiated 

most radiosensitive

Term

DIM- mitotic?

differentiation?

Definition

actively mitotic

more differentiated than VIM

Term

RPM- mitotic?

differentiation?

Definition

do not undergo mitosis, but can under specific conditions

highly differentiated

 

Term

FPM- differentiation?

mitotic?

radiosensitivity?

Definition

Highly differentiated (most)

do not divide, no mitosis

most radioresistant, least radiosensitive

Term
Sensitivity: the response to radiation can be predicted very crudely from the simplified classification of...
Definition
 population types
Term
Closed static cells would be classified as _________.
Definition
resistant
Term
Loss of reproductive ability in some cells of the population will occur, but whether the tissue or organ appears to be affected depends on the extent to which...
Definition
the tissue can function with a reduced number of cells
Term
the time interval between the radiation and the expression of the cell damage will be variable between
Definition
different populations
Term

examples of acute and late response:

-treating bone marrow and there is a short/long response time in reduction of blood count.

- treating intestinal lining and the response time is short/long

 

Definition

bone marrow = long time

intestinal lining = short time 

Term
Physical factors affecting response to radiation:
Definition

LET

RBE

Dose rate

fractionation

Term
biological factors affecting response to radiation:
Definition

cell cycle (differentiation)

Cell repair

Term
Chemical factor(s) affecting response to radiation:
Definition
Oxygen
Term
the model of raindrops on 100 squares of pavement relates to what cell survival model?
Definition
multi target, single hit
Term
when the deletion doesnt reattach
Definition
terminal deletion (one-break effect)
Term
when the broken part inverts then reattaches:
Definition
One-break effect- inversion
Term
when the broken part attaches to another chromosome 
Definition
(one break effect) duplication
Term
Two pieces are permanently broken off:
Definition
interstitial deletion (2-break)
Term
when two parts break off, one or both inverts, then both reattach to the chromosome arm
Definition
inversion (2-break)
Term
one or both broken parts attach to another chromosome
Definition
(2-break) duplication
Term
2 diff. chromosomes, both with a terminal deletion, switch broken portions.
Definition
translocation (2-break eff)
Term
Acentric fragment is
Definition
when two broken off pieces connect to eachother
Term
dicentric fragment is:
Definition
when 2 chromosomes with lost pieces attach to eachother
Term

ionizing radiation causes biologic damage.

the amount of damage can be assessed by looking at (3)?

 

Definition

direct and indirect actions

linear energy transfer (LET)

relative biologic effect RBE

Term
when alpha or beta particles or x-rays create ions which physically break the sugar phosphate backbones or break the base pairs of the DNA.
Definition
Direct actions
Term
radiolysis of water is considered 
Definition
direct/indirect actions
Term
Radiation interacts with the waer in the cell and the water is ionized. when the 'HOH+' attaches to another uncharged molecule, a free radical is formed. free radicals are ___ due to the presence of unpaired electrons which result when water molecules are split.
Definition
highly reactive
Term
: the rate at which the energy of the radiation was transferred to tissue
Definition
LET linear transfer energy
Term
high LET - ___ particles - give up energy quickly, cause more damage and ____ penetration
Definition
alpha, low
Term

Low LET (______) - 

low biologic damage, high penetration, do not give up energy quickly

Definition
x-rays and gamma rays
Term
: how much of the TEST radiation is needed to do the same amount of damage as 250 keV x-rays
Definition
RBE relative biologic effect
Term
RBE equation = 
Definition

dose of 250 keV x-rays

dose of test radiation

Term

set up equation:

It takes 50 cGy of a test radiation to produce an effect and 150 cGy of 250 keV x-rays produces the same effect. what is the RBE?

Definition
150/ 50 = 3.0
Term

LET is directly proportional to _____ and is closely related to _____.

 

High LET radiations have a ____ RBE.

Definition

RBE

biologic damage

 

high

Term
Most biologic damage results as a ____
Definition
break in the chromosomal backbone.
Term
: changes in DNA; single break in base. have a greater chance for repair
Definition
point mutations
Term
: double backbone beak
Definition
frameshift mutation
Term
: visible or detectable changes seen after a given dose of radiation within a given time period
Definition
response
Term
Acutely and chronic response refers to when the :
Definition
damage is expressed
Term
Time period for (Acute) Early Response:
Definition
within 6 months - usually can be repaired
Term
Chronic effects time period:
Definition
seen after 6 months; usually irreversible damage
Term
: replacement of damaged cells by the same type of cell - organ is restored
Definition
regeneration
Term
: Replacement of cells by a different type (like scars)
Definition
Repair
Term
Massive damage could result in _________ - failure to repair damage
Definition
necrosis
Term
SENSITIVE organs respond _____ than radioresistant organs. in the long run, the severity of damage may be worse in the ____ organ
Definition

sooner

radioresistant

Term

____ doses are more effective.

increased volume shows ____ response.

Definition

single doses (rather than fractionated)

 

increase

Term
name some acute responses
Definition

inflammation

edema

hemorrhage

denudation of mucosa

 

Term

name some chronic responses

 

Definition

fibrosis

atrophy

ulceration

stricture

stenosis

obstruction

Term
Acute skin responses:
Definition

erythema

most and dry desquamation

pigmentation

 

Term
Chronic Skin Repsonses:
Definition

atrophy

telangiectasia

necrosis

depigmentation

fibrosis

Term
Hair follicles are ______ sensitive.
Definition
Moderately
Term
Stem cells are _______... .
Definition
very sensitive to radiation
Term

rate from most to least sensitive

RBC PLATELETS WBC

Definition
most sens. RBC -> WBC -> PLATELETS least
Term
high doses to the bone marrow can cause permanent decrease in numbers of ___
Definition
stem cells
Term
platelets are resistant - have _____ lifespan
Definition
8-9 day
Term
erythrocytes are resistant- _____ lifespan
Definition
4 month
Term
In the digestive system, small intestine is ____ sensitive. rectum and liver cells are fairly resistant.
Definition
most
Term
although lung are considered to be resistant, they are responsive ...
Definition

in the high dose range.

 

Term
blood vessel damage causes:
Definition
occlusions
Term
Bone and cartilage: since growing cells are radiosensitive, there is increased damage in 
Definition

young people.

 

affects size and shape of bone

scoliosis

Term

CNS:

cells are DIFFERENTIATED and RESISTANT!

max. doses that cells can take before permanent damage:

Definition

Cord: 4500 cGy

Brain: 4500 cGy

Term
Male reproductive system is radioresistant except 
Definition
testes
Term
____ cGy can cause sterility in male
Definition
500-600
Term

Female repr. system:

dose for sterility depends on

Definition

age

-increased dose is needed for YOUNGER woman

Term
for females and males, there is danger of __ damage
Definition
genetic
Term
Skin : ___ cGy - temporary epilation and erythema
Definition
1000
Term
Lungs: causes
Definition
pneumonitis and fibrosis
Term
Heart: high doses cause 
Definition
pericarditis and pancarditis
Term
Bone: Decrease in damage with ___ in age.
Definition
increase
Term
Digestive: moderate doses cause inflammation of ____ ; small intestine is most sensitive. inflammation results in nausea, vomiting, and
Definition

mucous membranes

 

diarrhea

 

Term
Eye: __ cGy can cause damage; ___ cGy will cause cataracts
Definition
200 ; 700
Supporting users have an ad free experience!