Review Chapter 6-8 Flashcards
What is a cell?
The basic living unit of all matter
What does the protoplasm carry?
-Complex process of metabolism
-The reception and processing of food and oxygen
-The elimination of waste products
What do organic compounds contain?
Carbon, hydrogen, and oxygen
What are examples of organic compounds?
Lipids, carbs, proteins and nucleic acids
What do inorganic compounds contain?
Hydrogen and oxygen
What are examples of inorganic compounds?
Water and mineral salts
Which organic compound contains the most carbon of all the organic compounds?
Protein
How much of the cell contents is protein constitute?
Approximatey 15%
What is protein essential for?
Growth, the construction of new body tissue, and the repair of injured or debilitated tissue
What does enzymatic proteins(enzymes) function as?
Organic catalysts
What does enzymatic proteins (enzymes) control?
What does enzymatic proteins (enzymes) control?
The cell’s various physiologic activities
What do structural proteins provide?
Provides the body with its shape and form
Where is structural proteins found?
In muscle
Where is DNA contained?
In the nucleus
What does DNA contain?
All genetic information
How many chromosomes do humans have?
46
How many pairs of chromosomes do humans have?
23 pairs
What does RNA act as?
A messenger for DNA
What does RNA act as?
A messenger for DNA
What does RNA act as?
A messenger for DNA
What does RNA act as?
A messenger for DNA
How chromosomes does somatic cells have?
46 different chromosomes
How many chromosomes do gonadal cells have?
23 chromosomes each
What are chromosomes composed of?
What are chromosomes composed of?
What are chromosomes composed of?
protein and DNA
What are chromosomes composed of?
What are chromosomes composed of?
What are the components of the normal cell?
Cell membrane, cytoplasm, and nucleus
Somatic cells comprise all types of tissues, like?
Skin, muscle, nerve
What do somatic cells carry?
Carry out life functions of the individual
What do somatic cells pass on?
Identical genetic information to daughter somatic cells
What process does somatic cells go through to divide?
mitosis
What are the most sensitive types of somatic cells?
-Blood (RBC)
-Marrow
What are gonadal cells are responsible for?
The continuance of species
What is spermatogonium?
Male gonadal cellW
What is spermatogonium?
Male gonadal cell
What is oogonium?
female gonadal cell
What is the process gonadal cells go through?
meiosis
What can radiation damage to DNA result in?
The transmission of incorrect genetic information to future generations
What is another name for cell division?
cell proliferation
What is cell division?
The act of a single cell or group of cells reproducing or multiplying in number
What are the four phases cell division?
1st: Prophase
2nd: Metaphase (Radiation can induce chromosome damage)
What are the four phases cell division?
1st: Prophase
2nd: Metaphase (Radiation can induce chromosome damage
3rd: Anaphase
4th: Telaphase
What are four things that may occur if a cell is damaged by radiation?
-Cell may repair itself completely
-Cell may partially repair itself but not able to function correctly
-Cell may continue to function but will pass on incorrect genetic information
-Cell may die
What is the name of any permanent damage to chromosomes?
Chromosome aberration (or mutation)
What varies among the different types of radiation?
Charge, mass and energy
What is LET?
A measure of the rate at which energy is transferred from a beam of ionizing radiation to the tissue through which it is traveling
AS LET increases, what happens to biological damage and radiation damage?
Biological damage increases & increase in radiation damage
If the ability to penetrate increases, what happens to the LET?
Decrease in LET
Which type of ionizing radiation would produce a higher LET, gamma rays or beta particles? Why?
What are Low-LET radiation?
Gamma rays & X-rays
What are High-LET radiation?
-Alpha particles
-Ions of heavy nuclei
-Charged particles released from interactions between neutrons and atoms
-Low-energy neutrons
What does RBE take into consideration?
The amount of damage caused by different types of radiation
Radiation with higher LET will cause _____ biological damage?
more
How are LET and RBE related?
They are proportional
If LET increases, what happens to RBE?
Increases
Do x-rays have a higher or lower RBE compared to heavy ions?
Lower; Heavy ions have a RBE of 20 and 200-kev X-rays have a RBE of 1
What is oxygen enhancement ratio?
The ratio of the radiation dose required to cause a particular biologic response of cells or organisms in any oxygen-deprived environment to the radiation dose required to cause an identical response under normal oxygenated conditions
Is biological tissue more or less radiosensitive when it is well oxygenated, than when it is poorly oxygenated (hypoxic)?
More
What happens if enough somatic cells are affected?
The entire body processes may be disrupted
What happens if radiation damages the germ cells?
The damage may be passed on to future generations in the form of genetic mutations
Does more ionizing radiation damage come in the way of indirect effect or direct effect?
Indirect effect
What is direct effect?
A photon from the primary beam of radiation ionizes a molecule critical to the cell
What is an example of direct effect?
DNA
What is indirect effect?
After an initial ionizing event, there will be an ejected electron and either a secondary or scattered photon that may ionize another atom or molecule (H20)
Why does indirect effect cause the most radiation damage?
It creates another photon that may ionize another atom or molecule
What is radolysis?
When water gets irradiated it breaks down into molecules. These molecules can recombine and create harmful or harmless molecules
What are harmless molecules that can be made after radiolysis?
H2O & H3O
What are harmful molecules that can be made after radiolysis?
H2O2 (Hydrogen Peroxide)
Target Theory: Can a cell absorb radiation damage and continue to function unless a key or target molecule is damaged(DNA)?
Yes
What are the six damages to the cell nucleus?
-Instant death
-Reproductive death
-Apoptosis, or programmed cell death (interphase death)
-Mitotic, or genetic death
-Mitotic delay
-Interference with function
Target Theory: If the target molecule is damaged, what will happen to the cell?
It will die
What is instant death?
A large number of cells occurs when a volume is irradited with an x-ray or gamma ray dose approx. 1000Gy. Cell dies, no chance of recovery/repair
What is instant death?
A large number of cells occurs when a volume is irradiated with an x-ray or gamma ray dose approx. 1000Gy. Cell dies, no chance of recovery/repair
What is reproductive death?
Cell does not die, permanently loses its ability to procreate. Results from exposure of cells to doses of ionizing radiation in the range of 1-10Gy
What is apoptosis?
Non-mitotic, or non-division form of cell death that occurs when cells die without attempting division during the interphase portion of the cell cycle. Spontaneously occurs in healthy tissue and tumors. Example: skin cells die and are replenished
What is mitotic death?
Occurs when a cell dies after one or more divisions
What is mitotic delay?
Exposing a cell just before it begins to divide, failure of the cell to start dividing on time, after this delay normal mitotic functions can resume
What cells are radiaosensitive?
-Basal cells of the skin
-Blood cells such as lymphocytes and erythrocyte’s
-Intestinal crypt cells
-Reproductive (germ) cells
What cells are radiosensitive?
-Brain cells
-Muscle cells
-Nerve cells
What does the law of Bergoine and tribondeau state?
-Immature cells are more radiosensitive than mature ones
-Young tissue and organs are more radiosensitive than older ones
-The higher metabolism of a given cell, the more radiosensitive it will be
-Rapidly dividing cells are more radiosensitive
Is an embryo/fetus or a child/adult more susceptible to radiation damage?
Embryo/fetus because it contains a large number of immature cells
What cells are MOST radiosensitive?
Cells undergoing mitosis, blood cells, and gonadal cells
Which cells have reduced radiosensitivity? Why?
Nerve, brain, and muscle cells; Because people are born with nearly all of these cells and they are neither immature nor rapidly dividing
What is hematologic depression?
decreasing of active cells in tissue
What is depletion of immature blood cells?
Most blood cells in bone marrow, a decrease in immature blood cells in bone marrow ultimately reduces the number of mature blood cells in the bloodstream
What is repopulation after a period of recovery?
If bone marrow cell are not dead, they can recover and repopulate. Remember high doses can cause cell death, inability to repopulate
Why are RBC one of the most radiosensitive blood cells?
They are the primary oxygen carriers
What is the most radiosensitive blood cells? Why?
Lymphocytes; Because they have a short life span
What is epithelial tissue?
-Lines and covers body tissue
-The body continually regenerates this tissue, it is highly radiosensitive
Does muscle tissue divide?
No
Does nerve tissue divide?
Adults: no
