midterm 3

Question 1

what does an endocrine gland/cell do?

Answer 1

secretes hormones

Question 2

when are hormones released

Answer 2

upon stimulation

Question 3

what do target organs have

Answer 3

hormone-specific receptors

Question 4

what is an endocrine disrupting substance

Answer 4

exogenous substance or mixture that alter functions of the endocrine system and causes adverse health effects in an intact organism or its progeny or population

Question 5

what are the critical windows of exposure

Answer 5

exposure during early life stages may cause irreversible effects on organisms

exposure during reproductive endocrine processes affect populations

Question 6

what is atrazine used for

Answer 6

herbicide

broadleaf weed control on crops

systemic photosynthesis inhibitor

Question 7

what effects does atrazine have

Answer 7

impairs gonad development and reproduction

Question 8

what enzyme does atrazine effect

Answer 8

aromatase

Question 9

where is atrazine banned

Answer 9

in EU

briefly in BC (in 2012)

Question 10

where is atrazine not banned

Answer 10

canada and us

Question 11

what are the atrazine water guidelines in Canada and us

Answer 11

canada: DW: 5 μg/L, FW: 1.8 μg/L

US: DW: 3μg/L, FW: 10μg/L

Question 12

what is endocrinology

Answer 12

study of endocrine glands and their secretions (hormones)

Question 13

what is the basic definition of endocrine glands

Answer 13

ductless glands that secrete hormones into blood

Question 14

are hormones always produced by ductless glands

Answer 14

no

Question 15

what secrete hormones

Answer 15

small groups of cells, individual cells, or cells within various organs

Question 16

is secretion from an endocrine gland or cell unihormonal

Answer 16

no

Question 17

are multiple active chemicals produced by a cell

Answer 17

yes

Question 18

do most hormones have multiple production sites

Answer 18

yes

Question 19

are hormones only secreted into bloodstream

Answer 19

no, they are not only blood borne

Question 20

where are non-blood places hormones can be released

Answer 20

into lymph or extracellular fluids

Question 21

how does hormone action vary

Answer 21

it varies according to state of the target site

may be determined by the receptors on target cell

Question 22

do hormones act only on distant target sites

Answer 22

no

Question 23

what are autocrine signalling

Answer 23

cell targets itself

Question 24

what is paracrine signalling

Answer 24

targets nearby cell

Question 25

what did the evolution of multicellular organisms make necessary

Answer 25

to have coordinating systems to regulate and integrate the function of different cells

Question 26

what are the 2 mechanisms of hormone action

Answer 26

water soluble hormones lipid soluble hormones

Question 27

what hormones are water-soluble

Answer 27

all amino acid based hormones except thyroid hormones

Question 28

can water soluble hormones enter target cell

Answer 28

no

Question 29

what do water soluble hormones target

Answer 29

act on plasma membrane receptors

Question 30

how do water soluble hormones work

Answer 30

coupled G proteins to intracellular second messengers that mediate the target cell's response

Question 31

what hormones are lipid-soluble hormones

Answer 31

steroid and thyroid hormones

Question 32

what do lipid soluble hormones act on

Answer 32

act on intracellular receptors that directly activate genes

Question 33

what are the mechanisms of xenobiotic disruption of endocrine system

Answer 33

hormone receptor agonist hormone receptor antagonist

Question 34

what is a hormone receptor agonist

Answer 34

hormonal mimic toxicant can bind to receptor and induce a hormonal response

Question 35

what are hormone receptor antagonist

Answer 35

hormonal block blocks receptor so hormone can't bind and as a result blocks response

Question 36

what are the consequences of receptor mediated signalling

Answer 36

produce a non-,monotonic dose/concentration - response curves

Question 37

what is a non-monotonic dose response

Answer 37

curve whose slope changes direction within range of doses tested

Question 38

what are the consequences of receptor-meditated signalling

Answer 38

hormones act at low levels largest effect at lower doses saturation of receptors and thus effect at high doses desensitization and down-regulation of receptors at high hormone levels too many unused chemicals are bad for cell, can cause cell death

Question 39

how do EDCs break traditional toxicology concepts

Answer 39

higher dose =/= more toxic low dose = more toxic

Question 40

how does DDT effect alligators

Answer 40

developmental abnormalities of gonads abnormal sex hormone concentrations egg and embryonic abnormalities adverse effects on reproductive endocrine system

Question 41

is hormone action life stage specific

Answer 41

development is the most sensitive time for EDC effects

Question 42

what are the 3 lines of evidence that fuel concerns over endocrine disruptors

Answer 42

- increasing trends of many endocrine related disorders in humans - observation of endocrine-related effects in wildlife populations - lab studies linking chemicals with endocrine effects to disease outcomes

Question 43

what are the EDS endpoints set out by Canadian Government

Answer 43

reproduction and development are major endpoints

Question 44

what countries implement EDS testing

Answer 44

US, Japan, EU require information about endocrine disrupting effects of chemicals (US most explicit) Canada: no mandatory testing

Question 45

what are the effects of pulp and paper mill effluent on fish downstream

Answer 45

decrease in sex steroids, gonad size and delayed sexual maturity

Question 46

what is environmental effects monitoring (EEM)

Answer 46

pulp mill effluent monitoring program goals based on Fisheries Act

Question 47

what does EEM test and how often

Answer 47

sub lethal toxicity testing of effluent biological monitoring every 3 years but if no effect then every 6 years

Question 48

what are BPA effects

Answer 48

estrogenic abnormal penile/urethra development in males early sexual maturation In females increased neurobehavioral problems increased childhood obesity and onset diabetes

Question 49

what are 2 fish reproduction screening assay endpoints

Answer 49

vitellogenin secondary sex characteristics

Question 50

what is vitellogenin

Answer 50

synthesized and secreted by the liver under estrogen stimulation, transported in the blood to the ovary, taken up by growing oocytes, develops yolks

Question 51

are tubercles normal in males and females

Answer 51

males

Question 52

what causes tubercle production in males and females

Answer 52

androgen

Question 53

what does endogenous mean

Answer 53

produced within ( ex: androgen in males)

Question 54

what does exogenous mean

Answer 54

origin from outside origins (ex: androgen in females)

Question 55

what is linuron

Answer 55

ureic based herbicide

Question 56

what is the mode of action of linuron

Answer 56

anti-androgenic mode of action (inhibits androgen mediated )

Question 57

what are the effects of ethynyl estradiol

Answer 57

vitellogenin effects = gonad histopathology = population crash