Week 1 and 2
What triggers further development of the Oocyte?
Fertilization
The primitive streak is the transformation of what to what?
bilaminar to trilaminar embryo
What is the stimulus for cranial folding?
The Brain
What is another name for dysplasia?
dyshistogenesis
What limits the exchange between fetal and maternal circulation?
diffusion
Where does the amniotic cavity form?
epiblast
Gastrulation is the formation of what?(BE SPECIFIC)
germ layers
endoderm, ectoderm, mesoderm
What is cell differentiation?
specialization of tissues or organs(cells given specific tasks)
What is translocation?
transfer of a piece of chromosome to a non-homologous chromosome.
What are the fetal and maternal origins of the placenta?
fetal- chorionic sac
maternal- derived from endometrium(decidua basalis)
What does the chorionic sac consist of?(3)
extraembryonic mesoderm, cytotrophoblast, and syncytiotrophoblast
What do blood vessels of the allantois become?
umbilical arteries
What causes the folding of the tail?
growth of distal part of neural tube
What is trisomy 13 known as?
Patau syndrome
Cytotrophoblast becomes stretched and attenuates and eventually disappears leaving what layer?
syncytiotrophoblasts
What is the function of FSH? What hormone release does it cause?
targets growing follicles and mature follicles causing the release of estrogen
Explain the development of mesenchyme.
cells on the deep surface of the epiblast form a loose network of embryonic connective tissue(mesenchyme)
Name 2 methods used to determine embryonic age.
size, counting somites, development of limbs, head circumference, last known menstrual period
What is the difference between malformation and disruption?
Malformation is genetic due to intrinsic abnormal development process and disruption is caused by extrinsic factors(not inherited)
Anchoring villi attach firmly to the decidua basalis through what shell? This anchors the chorionic sac to what?
trophoblastic shell
decidua
What three structures collaborate to form the placenta?
extraembryonic mesoderm, cytotrophoblast, and syncytiotrophoblast
Blood vessel formation in the early cardiovascular system begins where and connects what 2 structures?
Begins in the extraembryonic mesoderm of the yolk sac
connects stalk and chorion
Pick any of the 3 germ layers and tell what types of tissues they produce(minimum 3)
Endoderm- lining of GI, lining of respiratory, thyroid and parathyroid glands, thymus, liver, pancreas
Mesoderm- connective tissue, cartilage, bones, striated smooth muscle, heart, blood, kidneys, serous membrane, spleen
Ectoderm- CNS, PNS, sensory epithelia of eyes, ears, nose, epidermis, neural crest cells, mammary glands, pituitary glands, subcutaneous glands, enamel of teeth
Explain how the genotype of an embryo can benefit a child in terms of birth defects.
embryo may inherit resistance rather than susceptability
At 8 weeks the chorionic sac grows, causing villi to become compressed. What happens because of this? What is formed?
decrease in blood supply
degeneration of villi to from avascular smooth chorion