Flashcards in Exam II Qs Deck (131)
An increase incidence of what condition is strongly associated with increase in maternal age?
Ambiguous external genitalia
Cleft palate is a result in a defect in what developmental mechanism?
Failure to fuse
Failure to merge
Faulty inductive tissue interaction
Disturbance in tissue reabsorption
Absence of normal cell death
Failure to fuse
Which condition is related to maternal imprinting?
Accessory placental lobes
Single umbilical artery
Phocomelia is most likely to be seen after maternal exposure to which teratogenic agent during first trimester of pregnancy?
The most serious threat of hydrop fetalis is CNS damage. The affected brain is enlarged and edematous, and when sectioned has a bright yellow color, particularly basal nuclei, thalamus, cerebellum, and cerebral gray matter, and spinal cord. The CNS damage is known as which of the following?
What is the initial initiator of future forelimb development?
A high concentration in amniotic fluid results in neural tube defects?
The most serious threat of hydrop fetalis is CNS damage. The affected brain is enlarged and edematous, and when sectioned has a bright yellow color, particularly basal nuceli, thalamus, cerebellum, cerebral gray matter and spinal cord. The CNS damage is known as which of the following?
The sclerotome arises from cells that were located in which of the following locations
The cardiogenic plate arises from where?
An inductive stimulus from which structure stimulates the transformation of the epithelial sclerotome into secondary mesenchyme?
Intermediate mesoderm is the precursor of the:
Name the 4 stages in the development of the chorionic villi, state characteristics of each
1. Previllous embryo - no villi via trophoblast
2. Primary villous stage - solid, cytotrophoblastic, ectodermal primary villi appear
3. Secondary villous - mesodermal cores appear within primary villi
4. Tertiary villous stage - blood vessels within mesenchymal core of secondary villi
What tissue in the mature placenta directly interfaces with the maternal uterine connective tissue?
None of the above
Describe the location of the chorionic plate in the mature placenta
(mesoderm) faces away from the chorionic villi towards the chorionic cavity
Describe the location of the cytotrophoblast shells in the mature placenta, what are they formed by?
Formed by expansion of the cytotrophoblastic columns over the maternal decidual cells
List the 5 structures involved in the final development of the placenta
What are the anchoring villi of the mature placenta anchored to?
The cytotrophoblastic shell (as opposed to floating villi)
What maternal tissues are lost at childbirth? (3)
What is the fate of the decidua capsularis?
Distinguish between early vs. late placenta
Thick, low permeability, small SA, total diffusion conductance is miniscule
Thin, high permeability, large SA, large increase in placental diffusion
State the oxygen pressure gradient near the end of pregnancy of the mother and fetus
PO2 mother = 50mmHg
PO2 fetus = 30mmHg
How does adequate oxygenation occur with such a low pressure gradient near the end of pregnancy?
Fetal Hb has a greater affinity for O2
Fetal blood has more Hb than mother (50%)
Define Bohr effect
Hb can carry more O2 at a low PCO2
Curve is shift left for fetal, right and down for maternal
Define the double Bohr effect
The double shift in the maternal blood and fetal blood
Where is hCG secreted from, when, and what is its function?
Via syncytial trophoblast cells into maternal fluids
Measurable at 8-9d after ovulation, max = 10-12w pregnancy
Prevents degradation of corpus luteum & give growth
Causes CL to secrete more progesterone & est
Exerts interstitial cell-stimulating effect on testes of male fetus = testosterone production
Where is estrogen secreted from, when, and what is its function?
Syncytiotrophoblast cells of placenta
Toward end of pregnancy, 30X more via androgenic steroid compounds (mom&fetal adrenal glands) Converted by trophoblast cells into estradiol, estrone, and estriol
Uterine, breast, external genitalia enlargement
Breast ductal growth
Relaxation of pelvic ligaments
Where is progesterone secreted from and what is its function?
Small quantities = corpus luteum
Large quantities = placenta
Causes decidual cells to develop in the endometrium
Decreases contractility of pregnant uterus
Increases secretions of fallopian tubes and uterus
May work w/ est to prepare breast for lactation
When is human chorionic somatomammotropin secreted and what is its function?
Decreased insulin sensitivity and decreased utilization of glucose by mother
General metabolic hormone