Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/24

Click to flip

24 Cards in this Set

  • Front
  • Back
From what cells is the placenta derived from?
Trophectoderm from blastocyst.
What trimester of pregnancy can you get PID?
ONLY FIRST!
What is decidua?
Maternal endometrial contribution to placenta
Umbilical arteries carry what kind of blood and in what direction?
DEOXYGENATED BLOOD between fetus and placenta. There are 2 umbilical arteries
What kind of blood does the umbilical vein carry?
Only 1 umbilical vein. Carries from placenta to fetus.
What is the importance of the ductus venosus?
Ductus venosus shunts a significant minority of blood flow away from LIVER and to heart. In conjunction with the foramen ovale, this is how blood is preferntially shunted TO THE BRAIN!
How many layers separate fetal and maternal blood by the third trimester?
ONE! Syncytotrophoblasts.
What are the primary functions of trophoblasts?
Hormone production

Prevents immune rejection by retention of HLA-G molecule that is recognized by maternal immune system.

Nutrient transport.
Where is the primary site of hormone production in the placenta?

What hormones are produced?
Syncytotrophoblasts!!

They produce hCG, progesterone (placenta maintains progesterone levels beyond the corpus luteum), estiol, hCS.
When is hCG secreted during pregnancy?

What is the pattern of its secretion?
By day 8 of ovulation. Produced by syncytotrophoblasts

1st 5 weeks: Maternal hCG serum levels DOUBLE every 1.5 days

after 5th week - levels DOUBLE every 2.3 days.

Levels plateau and decline starting at wk 10.

INSUFFICIENT INCREASES likely will result in a non-viable pregnancy.
Why are hCG levels increasing up until 10 weeks of pregnancy?
hCG is responsible for maintenance of corpus luteum.
If hCG levels are at 2,000 (cut-off value) and no fetus is VISIBLE on ultrasound, what is potential problem?
ECTOPIC. Ectopic pregnancies continue to produce normal levels of hCG consistent with a pregnancy.
hCG acts by binding to what receptor on the corpus luteum?
on the LH/CG receptor

High levels of hCG can also cross-react with TSH-receptor. Hyperthyroidism can be secondary to high levels of hCG.
What is the primary steroid production site in placenta?
AGAIN, syncytotrophoblasts.
What is the relevance of placenta lacking P450c17?
Cannot convert pregnenolone to DHEA, and thus can ONLY BE CONVERTED to progesterone. Important since placenta is main site of progesterone synthesis beyond wk 10.
What are the roles of progesterone during pregnancy?
1) Prepares endometrium for implantation

2) Uterine smooth muscle relaxant (prevents pre-term delivery)

3) Maintains pregnancy

4) Blocks immune rejection from parent of fetus.
What is the significance of estriol (E3)?
It is 1% as potent as estradiol.

Estriol will only appear in the setting of a placenta. Used as a marker for fetal well-being.

Pregnenolone is converted into 16OH-DHEAS (which is unique to fetuses). The 16-OH-DHEAS is then converted to estriol.

Placenta has EXTREMELY HIGH AROMATASE ACTIVITY.
Where is estriol derived from?
PRIMARILY FROM THE ADRENAL CORTEX. Marker for well-being and aneuploidy/
What are fetal actions of estrogen?
Fetal control of maternal physiology.

Vasodilation of spiral arteries.
If there is no progesterone secretions, what happens to deidualization?
DECIDUA CANNOT APPEAR WITHOUT PROGESTERONE. Thus no implantation.
What are the 5 functions of FSH?
1) Stimulates aromatase in granulosa cells!

2) Saves follicles from atresia

3) Stimulates FSH receptors

4) Increases LH receptors

5) Increases surrounding vascularization
What is the importance of day 3 FSH?
Determine youth/viability of ovaries.
How long does it take egg to reach uterus?
Around 1 week travel through fallopian tube.
What is ovarian hyperstimulation syndrome?
Occurs in young women undergoing preparation for IVF.

Presents with BLOATING, NAUSEA, ABDOMINAL DISCOMFORT.

Cause: Corpus Luteum secretes a lot of VEGF, which can cause hypotension, edema, leaky vessels.

Pulmonary edema, hypercoaguable state, renal failure.