Embryo and fetal development and physiology Flashcards
What form is the embryo in during implantation?
blastocyst
Where do male gonads develop from?
Wolffian ducts
Where do female gonads develop from?
Mullerian ducts
How many layers separate the maternal and fetal circulations?
3
What create a high surface area/volume ratio in the placenta?
fetal villi, suspended in intervillous spaces bathed with maternal blood
Transfer of O2 and CO2 occurs by what mechanism?
passive diffusion
Transfer of iron/vit C occurs by what?
active transport
Transfer of glucose and immunoglobulins occurs how?
facilitated diffusion
Is there a large or small placental reserve?
large - can afford to lose up to 30/40% of placental villi without evidence of placental insuffiency
What does the embryo consist almost entirely of?
water
When does a fetus become entirely dependent on its mother for nutrients?
10 weeks
When does heart start beating?
4/5 weeks
Chest movements are detected when?
11 weeks
What prevents alveolar collapse after birth?
surfactant
What makes surfactant?
type 2 pneumocytes
