Lecture 7 Flashcards
Study of the adverse effects of chemicals on living organisms:
Toxicology
Toxicology is an intersection between ________ and _________
biology and chemistry
Interaction of toxicant with biological system depends on (2):
- Chemical/physical characteristics of toxicant
- Biological characteristics of organism
__________ makes the poison
Dose
On a dose-response curve the dose is located on the _ axis and the response on the _ axis
x
y
What are the 3 assumptions for dose response curves:
1) Response is due to the chemical
2) Magnitude of response is due to the dose
3) Quantifiable method to assess response
What are some different ways that a dose can be administered:
- injections (needle)
- diet (food, water)
- waterborne exposure (gills, skin)
- airborne (lungs, skin)
What are some units for the dose that we can see on the x axis:
- amount of toxicant (mg)
- amount of toxicant per weight (mg/kg) or volume (mg/L)
- amount of toxicant per weight per time (mg/kg bw /d)
- may also be time (seconds - years)
Biological responses are ______________ some are very sensitive and some very resistent
variable
Illustrate a response frequency curve and tell me where most responses are located
most respond at middle of curve
What does LC50 mean?
at what concentration do we see 50% of the fish die
EC =
LC =
IC =
- effective concentration
- lethal concentration
- inhibitory concentration
MED =
Minimally effective dose / at what concentration you actually see a response (=threshold dose)
Name the 4 curves on the D-R Continuum of effects
- enzyme induction
- tissue lesions
- behavioral changes
- lethal effects
A biological response to a chemical that gives a measure of exposure and toxic effect:
Biomarker
