Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Somewhat school work > Chemical pathology C22 > Flashcards

Chemical pathology C22 Flashcards

1
Q

What happens to the level of hormones and peptides produced by the placenta as the size increases

A

the levels of hormones increases with exception of hCG as the levels peak before the end of the first trimester

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

name four major placental hormones

A

hCG
progesterone
oestrogen
HPL

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

name three other hormones and peptides used in prenatal screening

A

Inhibin (peptide)
PAPP-A (peptide)
AFP (peptide)

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

What is hCG made by and what are the two subunits it has

A

it is made by syncytiotrophoblats of the placenta and has a alpha and beta subunit

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

what hormones is the alpha subunit common to?

A

TSH
FSH
LH

and they are encoded by a single gene

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

what is special about the beta subunit

A

it is unique to hCG

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

what is the function of hCG

A

it stimulates the corpus luteum to continue producing progesterone in early pregnancy until the placenta is able to produce enough progesterone to maintain pregnancy

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

what is the first hormone produced by the placenta

A

hCG

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

how long after conception can hCG levels be detected and when does it reach maximum levels

A

3 weeks and this means that hCG levels can be detected before the first missed period

it reaches maximum levels between 8 and 12 weeks and from then onwards the levels gradually decline as the placenta takes over the production of progesterone

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

what affects the interpretation of hCG levels

A

the antibody used in the lab assay

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

what is the diagnostic purpose of hCG

A

used to confirm pregnancy (for obvious reasons)
marker for trophoblastic disease (tumour marker)
retained products of conception
prenatal screening
used to confirm expected gestation age BUT does not establish gestation age as the ranges are too wide and people with multiple previous pregnancies tend to have higher levels of hCG

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

what type of hormones are progesterone and oestrogen

A

steroid hormone and it is produced from cholesterol (derived from maternal cholesterol)

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

what produces progesterone and oestrogen

A

at first it is the corpus luteum under hCG instructions then it is the produced by the placenta

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

what is the function of progesterone

A

prevents menstruation and maintains the endometrium for implantation of the blastocyst and placental invasion

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

what organs play a role in the production of oestrogen in pregnancy

A

the placenta
foetal adrenal gland
foetal liver

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

what is the primary oestrogen of pregnancy

A

Oestriol (E3)
- 10% unconjugated and the rest is conjugated (sulphate and glucuronate)

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

What is the function of oestrogen in pregnancy

A

maintains fetal and uterine well-being

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

what is HPL (human placental lactogen) similar to?

A

growth hormone and to a lesser extent it is also similar to prolactin

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

what is the function of HPL

A

in the mother it prevents uptake of glucose and promotes lipolysis in order to provide glucose for the fetus while the mother uses the fatty acids for energy
it also prepares mamillary glands for lactation

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

what is the function of Activin and Inhibin

A

they are regulators for GnRH, hCG and steroids

  • inhibin is a negative feedback regulator of FSH and the placenta secretes large amounts of inhibin to prevent rise in FSH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where are Activin and Inhibin produced

A
  • ovaries
  • pituitary
  • placenta
22
Q

what is the function of PAPP-A (Pregnancy associated plasma protein A)

A

it is a metalloproteinase which is responsible for cleaving insulin-like growth factor binding protein

23
Q

where is PAPP-A produced

A

by the syncytiotrophoblast

24
Q

which hormone is similar to AFP

A

albumin. (AFP is the fetal albumin)

25
where is AFP produced
initially in the yolk sac and then in the fetal liver
26
when do the AFP levels peak
after the first trimester and then decrease to reach adult levels at 10 months of age
27
what is AFP used for?
it a marker for hepatocellular carcinoma and germ cell tumors
28
what is the purpose of prenatal screening
this is a non invasive test used to determine the risk that a particular disease is present in the unborn fetus
29
what is important to note about prenatal screening
it does not provide a diagnoses as it uses protein levels and peptides that are usually elevated in particular diseases and uses that as a risk checker
30
what are the characteritics of a good screening test
should not be expensive easy to perform safe and non invasive give reproducible results must be able to detect disease or condition on time must be sensitive: must have a low false negative rate
31
when is prenatal screening important
pregnancy at the age of 35 and above family history of: neural tube defects chromosome abnormalities single gene disorders previous child with conditions abnormalities identified during pregnancy
32
what is the importance of prenatal screening
gives the health care practioner the risk ratio and informs them if they need to proceed and perform a prenatal diagnostic test.
33
what is the function of prenatal diagnostic testing
the intended purpose is to come up with a definitive diagnosis this is usually invasive and procedures carry higher complication risks
34
give two examples of prenatal diagnostic testing
Amniocentesis and Chorionic villus sampling
35
what happens with Amniocentesis
it is performed at 15 to 18 weeks of gestation and amniotic fluid is obtained transabdominally under ultrasound guidance tests for karyotype, DNA analysis, biochemistry and enzyme studies the complications include miscarriage, transient amniotic fluid leakage and intrauterine infection
36
what happens with Chorionic villi sampling
performed at 8 to 13 weeks of gestation developing placenta is obtained transcervically or transabdorminally test for karyotype, DNA analysis and enzyme studies the complication is grater than in amniocentesis and include miscarriage, infection, bleeding and limb defects and also cause contamination of martenal tissue
37
what are the two types of prenatal screening
imaging - ultrasound, MRI and Doppler Maternal serum biochemistry - AFP, PAPP-A, free beta hCG, total hCG, unconjugated oestriol and inhibin
38
MoM=
patient results / median for GA
39
what increases the incidence of neural tube defects
dietary folate deficiency
40
name three types of neural tube defects
spina bifida, meningomyelocele and anencephaly
41
what happens to AFP in neural tube defects
leaks through amniotic fluid through the neural tube defect and passes across the placenta into the maternal serum
42
what is the MoM in neural tube defects
2 to 2.5
43
what characterisis down syndrome
trisomy 21
44
what increase the risk of bearing a child with down syndrome
pregnancy after the age of 35
45
what can you expect to find on ultrasound for children with down syndrome
increased nuchal translucency - thickness of subcutaneous fluid at the back of the neck in 75% cases of D.S nuchal translucency is greater than 95 percentile
46
down syndrome screening (first trimester)
ultrasound nuchal translucency is increased PAPP-A is decreased (<0.5MoM) Free beta hCG is increased (>1.5 MoM)
47
down syndrome screening (second trimester)
AFP decreased unconjugated oestrial is decreased total hCG is increased Dimeric inhibin A is increased
48
what is Edwards syndrome
trisomy 18 this has a poor prognosis
49
Edwards syndrome screening (first trimester)
ultrasound NT is increased PAPP-A is decreased free beta hCG is decreased
50
Edwards syndrome screening (second trimester)
AFP is decreased unconjugated eostrial is decreased total hCG is decreased

Somewhat school work (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions