Diffusion through placental membrane

Question 1

Simple diffusion from sinuses through villus membrane down pressure gradient to fetus
from maternal blood − _____ mm Hg

mean PO2 in villus _____mm Hg

mean PO2 in fetal blood _____mm Hg

Answer 1

from maternal blood − 100 mm Hg
mean PO2 in villus − 50 mm Hg
mean PO2 in fetal blood − 30 mm Hg

Question 2

Fetal Hb (Hb F- 22) has higher affinity for O2: can carry ____more O2 than maternal Hgb

Answer 2

20-30%

Question 3

____shift of Oxy-Hb curve (newborn) ; later shift to ____

Answer 3

left, right

Question 4

Fetal Hb concentration in blood is ____ greater than in mother

Answer 4

50%

Question 5

Anemia when Hb ___g/dl (newborn) and ___ g/dl in older than 3 months

Answer 5

<13, < 10

Question 6

CO2: builds up until it is slightly higher in fetus umbilical arteries_____ than in intervillous space ______

Answer 6

(48 mm Hg), (43 mm Hg)

Question 7

Affinity for CO2 is _____ in fetus, favoring transfer from fetus to mother

Answer 7

lower

Question 8

Receptor mediated endocytosis from mother: ____

Answer 8

LDL

Question 9

Renin increases late in gestation due to

Answer 9

1. Renal sympathetic nerve activity
2. Reduction in Na and blood volume
3. Change in renal perfusion pressure

Question 10

Diagnosis of fetal well-being:

Noninvasive

Answer 10

Transvaginal ultrasound: visualize vertebrae, kidneys,

bladder, fingers and toes by 12 wks gestation

Question 11

Diagnosis of fetal well-being

Invasive

Answer 11

Amniocentesis: 14-16 wks; when amniotic cavity contains 150-200 ml (remove 20 ml); with simultaneous ultrasound; karyotyping, biochemical analyses, DNA

Question 12

cytogenetic and biochemical testing recommended after 10 wks gestation; usually 2nd and 3rd trimester

Answer 12

Chorionic villus sampling

Question 13

transabdominal; from 17 wks into umbilical vein about 1 cm from placental cord insertion site

Answer 13

Fetal blood sampling