Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Nutrition Through Life Midterm 1 > 3: Teratogensis > Flashcards

3: Teratogensis Flashcards

0
Q

Do birth defects always result in altered health outcomes?

A

No, can cause zero changes to very major depending on the kind of defect and the tissues or organs affected.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

What is teratogensis.

A

Non reversible malformations (morphological defects) that are present at birth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the leading cause of death for infants?

A

Birth defects. Largely for organ failure (heart most common, 30%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What percentage of birth defects come from unknown causes?

A

65-70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What percentage of pregnancies are lost post implantation?

A

30%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The period of time in a pregnancy with maximal cell division and differentiation is called…

A

Organogenesis (3-8 weeks). Cell organization, cell differentiation, and organogenesis take place.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Does the rate of differentiation and development during the first few weeks of pregnancy affect the rest of the development?

A

Yes, the time “lag” at this time can not be compensated for later, so can lead to birth defects or low birth weight.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Hyperplasia

A

Increase in cell number. Maximum vulnerability to teratogensis during this phase (17 days to 8 weeks).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Hypertrophy

A

Increase in cell size. Only starts occurring after 8 weeks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hypertrophy + hyperplasia =

A

Cellular division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Tropoblast goes on to form the…

A

Placenta.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Inner cell mass (embryoblast) goes on to form the…

A

Embryo.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Histotrophic nutrition

A

Diffusing and digesting surrounding blood cells and tissue. Embryo does for the first 20-25 days before the placenta can be used for nutrition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Preimplantation phase- how long? Susceptibility to teratogens?

A

Less than one week. Increase in number of cells but now the size of cells yet. Low susceptibility to teratogens and few developmental abnormalities because fate of cells not yet determined (great restorative capacity). Toxin exposure will have little or no effect, or will prevent implantation (lethal).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Gastrulation phase- what happens? How long? Susceptibility to teratogens?

A

Form the three germ layers: ectoderm (brain, nerves, skin), mesoderm (muscles, vascular system, excretory system), endoderm (digestive, respiratory, glandular). Very susceptible to teratogens. 2-3 weeks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Organogenesis- how long? Susceptibility to teratogens? Major characteristics?

A

Organs and body structures are established. Extremely susceptible to birth defects. Heart beat starts and neural tube closes. 3-8 weeks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Fetal/neonatal- how long? Susceptibility to teratogens?

A

8 weeks to birth. Functional defects more likely to arise, critical defects much less likely.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why should you wait several months before getting pregnant if you have stopped taking certain medications?

A

Medications can be stored in the fat deposits and can be released throughout the duration of the pregnancy. Can take several months to clear completely. Ex. Some seizure medication, acutane.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the leading development based cause of low IQ?

A

Fetal alcohol syndrome or alcohol consumption during pregnancy of some kind.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What factors may be protective against teratogenic environmental agents?

A

Anti oxidants, polyphenols, omega 3. Genes will also play a factor in susceptibility.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What can increase risk of birth defects associated with having an infection during pregnancy?

A

Inflammation and a secondary zinc deficiency,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What can increase risk of birth defects associated with having a chronic disease (obesity, diabetes) during pregnancy?

A

Inflammation. May be harder to increase frolic acid status as well.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Zinc deficiency from infectious agents or alcohol/drug use results from…

A

Metallothioniene, in the placenta, binds to metals. If there is a toxin and the metallothioniene concentration has increased as a result, it will bind zinc up with the other heavy metals and result in a zinc deficiency. Due to cadmium in cigarettes, may be beneficial for all smoker to take zinc while pregnant to counter this effect.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Coumadin causes what deficiency?

A

Vitamin K. Is an agonist to.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Methothexate (chemotherapeutic anti inflammatory agent) caused what deficiency?

A

Binds up frolic acid (folate antagonist).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What deficiencies can anti convulsants cause?

A

Zinc and folate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the dose response relationship between alcohol and birth weight?

A

Each oz of alcohol causes a decrease of 160 g in birth weight.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Three alcohol related birth defects (ARBD):

A

Microcephaly (small head circumference), heart/lung malformations, minor physical abnormalities (ex cleft lip).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

To diagnose fetal alcohol syndrome need 2/3 of the following characteristic plus a maternal history of alcohol consumption.

A

Prenatal and/or postnatal growth retardation (head circumference, weight, height), neurodevelopment + behavioural characteristics (decreased attention span/IQ), characteristic facial features

29
Q

Does the point of time in the pregnancy that alcohol was consumed matter?

A

In the first trimester will have an increased risk of neural tube defect. In the last trimester, when brain development is rapid, will have increased risk of damaging neurodevelopment and behavioural characteristics.

30
Q

What about the fetus’ metabolism makes it especially vulnerable to alcohols toxic effects?

A

Detox and clearance is less developed. Alcohol crosses the placenta freely. alcohol dehydrogenase (which metabolizes 95% of alcohol in adults) creates acetaldehyde which the fetus can not break down (no acetaldehyde dehydrogenase), so will build up and create DNA and protein damage.

31
Q

What are some of the affects alcohol will have on the nutritional and health status of the fetus in the uterus?

A

Folic acid and zinc deficiency, placental toxicity (decreased absorption of everything), fetal hypoxia (lack of oxygen because used up in metabolizing toxins), tend to displace nutritious calories from food with alcohol so poorer diet quality

32
Q

Neural tube defects

A

Abnormalities of the fetal spine and central nervous system.

33
Q

Anencephaly

A

Only brain stem, brain tissue degraded by the amniotic fluid. Die shortly after birth.

34
Q

Spina bifida

A

External pouching of spinal membrane, can be surgically corrected. May or may not have lasting damage (form of paralysis usually).

35
Q

What decrease in risk is seen when folate is supplemeted?

A

70% decrease in risk of neural tube defects. Can even compensate for an inborn error of folate metabolism in the mother.

36
Q

In mothers of infants with neural tube defects, what two blood levels are found?

A

Low folate, high homocysteine

37
Q

Accumulation of s-adenosyl homocysteine (SAH) leads to:

A

Inhibition of DNA methy transferase reactions, DNA hypomethylation, and altered gene expression.

38
Q

What might be a better supplement than Folic acid?

A

5-methyl-tetrehydrofolate which is the active form that requires no further metabolism, is well absorbed, and doesn’t mask a B12 deficiency.

39
Q

What much does plasma homocysteine concentration change during pregnancy?

A

Decreases 30-60%. Lower concentration more with Folic acid supplementation.

40
Q

What is high homocysteine levels a risk factor for?

A

Preeclampsia, spontaneous abortion, recurrent early miscarriages, cleft palate/lip, lower birth weight (homocysteine levels at conception, 8 wks, and birth is inversely related to birth weight).

41
Q

What level of Folic acid is recommended for most women? What level for those with inborn errors in metabolism?

A

400 micrograms per day. Metabolic error could require as high as 800. Most women get 230 from food and 100 from fortification, so most below ideal threshold.

42
Q

Iodine impact: deficiency? Excess?

A

Cretinism (mental and physical retardation), congenital goiter. See similar effects in deficiency and excess.

43
Q

Fluoride impact: excess?

A

Spina bifida occulta (not externally visible). See in places where fluoride content of soil is unusually high (in drinking water and food).

44
Q

Vitamin d: deficiency? Excess?

A

Deficiency can cause fetal rickets (bones not mineralized adequately). Excess see facial abnormalities and mental retardation.

45
Q

Vitamin A: deficiency? Excess?

A

Deficiency see eye abnormalities and microcephaly. Excess see CNs abnormalities.

46
Q

Protein deficiency?

A

Must be severe to see impact, have a sparing effect to protet pregnancy. Will see microcephaly and low IQ.

47
Q

Vitamin K deficiency?

A

Heart defects and growth retardation. Also called “Coumadin syndrome”

48
Q

Potassium deficiency.

A

Kidney abnormalities.

49
Q

Copper deficiency

A

Connective tissue defets, brain/bone abnormalities (“Menkes disease”)

50
Q

Zinc deficiency

A

Neural tube defects, growth stunting.

51
Q

Why have birth defects accounted for a larger portion of infant mortality over the years?

A

Improvements in obstetrical care, increase exposure to medication and toxins during pregnancy, and decrease in deaths due to infections.

52
Q

What proportion of all human pregnancies result in the birth of a healthy infant without birth defects.

A

Less than 50%. Most of this is attributed to post implantation loss.

53
Q

What does fertilization begin with and end with?

A

Begins with the sperm penetrating an oocyte, ends with the creation of a zygote.

54
Q

What is the solid sphere of cells from the cell division in the zygote called?

A

Morula.

55
Q

What is the cavity in the morula called? When it appears, what is the whole structure now called?

A

Blastocoele forms. Now it is known as a blastocyst.

56
Q

What two cell types are forming in the blastocyst?

A

Embryoblast (inner cell mass and inside of the blastocoele) and the tropoblast (cells outside the blastocoele).

57
Q

How is an implantation site created for the blastocyst?

A

The tropoblast cells secrete proteolytic enzymes which around the epithelial uterine lining and create an implantation site.

58
Q

What cell phase to teratogenic agents have lethality or no effet (potency)?

A

Pluripotency (pre implantation stage).

59
Q

What is Henson’s node?

A

The invagination that start Gastrulation.

60
Q

Why does the neural tube need to close by the 27th day?

A

Nerves will be degraded by the amniotic fluid.

61
Q

At what point to we consider the conceptus a fetus and no longer an embryo?

A

The 8th week (end of organogenesis) when all essential external and internal structures are present.

62
Q

At the 8th week what has started to account for most of the nutrient needs?

A

The placenta.

63
Q

Do medications easily cross the placenta?

A

Yes, almost all do.

64
Q

What is the trimester where the fetal brain is most sensitive to the effects of alcohol?

A

Third trimester (goal to seek sobriety by then to escape brain damage).

65
Q

What is the frequency of infants with FAS in alcoholic mothers?

A

30-50%

66
Q

What percentage of women consume some alcohol during pregnancy?

A

82%

67
Q

What is the most common cause of vitamin and trace element deficiencies in adults?

A

Chronic alcohol use.

68
Q

What is the most common type of birth defect wordwide?

A

Neural tube defects

69
Q

What percentage of NTDs are related to folate deficiency or abnormal folate metabolism?

A

50-75%

70
Q

What deficiencies can cause homocysteine to accumulate?

A

B6, B12, folate

71
Q

What preconception blood value might identify mothers who are at an increased risk for complication and may benefit from Folic acid supplementation?

A

Elevated homocysteine

Nutrition Through Life Midterm 1 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions