Germ Layers
This layer replaces the hypoblast and becomes the lining of internal organs.
What is the endoderm?
This structure marks the beginning of gastrulation.
What is the appearance of the primitive streak?
This subdivision of mesoderm specifically contributes to heart development.
What is the lateral plate mesoderm?
Folding transforms the embryo into this structural arrangement.
What is a "tube within a tube"?
The first functional organ to develop.
What is the heart?
This layer gives rise to muscle, connective tissue, and the cardiovascular system.
What is the mesoderm?
Cells enter the embryo through this structure.
What is the primitive groove?
This layer of the lateral plate mesoderm directly forms the heart.
What is the splanchnic mesoderm?
This type of folding moves the heart into the thoracic cavity.
What is cranio-caudal folding?
This structure forms the initial heart tube.
What is the first heart field?
This layer forms both the nervous system and the skin.
What is the ectoderm?
This is the expanded cranial end of the primitive streak.
Cardiogenic mesoderm originates from this structure before migrating cranially.
What is the primitive streak?
This type of folding brings the paired endocardial tubes together, so they can fuse.
What is lateral folding?
This heart field contributes to elongation and added complexity
What is the second heart field?
All 3 germ layers originate from this structure.
What is the epiblast?
This term describes cells moving inward and detaching from the surface.
What is delamination?
This crescent shaped structure forms from cardiogenic mesoderm and represents the earliest visible stage of heart development.
What is the cardiac crescent (first heart field)?
This structure receives systemic venous blood and serves as the inflow region of the primitive heart tube.
What is the sinus venosus?
These paired structures fuse to form the primary heart tube.
What are endocardial tubes?
This germ layer is formed last, after cell migration through the primitive streak has ceased.
What is the ectoderm?
This cell movement process both narrows and lenghtens the primitive streak during development.
What is convergent extension?
This process brings the right and left cardiogenic regions together at the midline, allowing formation of the primitive heart tube.
What is lateral folding?
This is the correct direction of blood flow through the primitive heart tube.
What is: sinus venosus- primitive atrium-primitive ventricle- bulbus cordis- truncus arteriosus?
This condition results in mirror-image organ positioning.
What is situs inversus?