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15 Cards in this Set

  • Front
  • Back
umbilical veins
PAIRED vessels that deliver nutrient/O2-rich blood from the placenta to the embryo
vitelline veins
Drain the yolk sack
anterior & posterior cardinal veins
Return venous blood from the anterior and posterior parts of the embryo, respectively.
sinus venosus
Posterior chamber of the heart that receives venous blood
dorsal aorti
PAIRED vessels that receive blood from the aortic arches and distribute it to the cranial and caudal ends of the embryo
segmental arteries
Supply posterior segments of the embryo
umbilical arteries
PAIRED vessels that distribute blood back to the placenta for reoxygenation.
Why is cardiovascular system the first system to develop?
The embryo is growing so fast that simple diffusion from placenta to embryo is not sufficient to supply O2 and nutrients to its tissues. Circulation develops to meet these requirements.
What day does the heart appear? What day does it begin to beat?
Appears at day 18.
Begins to beat at day 21.
Shape of embryo at day 18?
Flat disk
3 germ layers?
1. ectoderm
2. mesoderm
3. endoderm
Which germ layer does heart arise from? What part of that germ layer?
Splanchnic mesoderm
Describe the body cavities at day 18.
They are paired and lie adjacent to the splanchnic mesoderm
angioblastic cords
PAIRED longitudinal cords formed by cells within the splanchnic mesoderm; earliest appearance of the heart
endocardial heart tubes
Angioblastic cords begin to hollow out to form these structures.