Trilaminar Lecture Flashcards
Gastrulation
Process by which we transform bilaminar embryo, epiblast, hyperblast to trilaminar
Ectoderm, mesoderm, endoderm
Neurulation
Formation of neural tube
While notochord develops
Induces the overlying ectoderm to thicken and form the neural plate
Ectoderm
Epidermis of skin, neurulation, formation of CNS, rolls from plate to tube, differentiate rostrally to brain and caudally to spinal cord
Neural plate
Thickened ectoderm that grows and creates neural folds.
Third week
Neural plate invaginates to form median neural groove, with folds on either side
Neural tube
fusion of two neural folds
Paraxial mesodermal cells
(next to midline skeleton) Organized into segments known as somites beginning on day 20.
Intermediate mesoderm
Important in kidney and genital development, ovaries and testes. Grow and proliferate to form urogenital ridge on posterior wall of abdomen
Lateral mesoderm
Intra-embryonic mesoderm, spaces form that will form body cavity, around heart, house lungs, abdominal cavities
Somatic mesoderm (lateral)
Forms parietal serous linings
Splanchnic mesoderm (lateral)
Forms the visceral serous coverings of the organs, migrates rostrally to the cardiogenic area region, where it forms the heart and great vessels. Embryo will fold head to tail
Septum transversum
Formed by lateral mesoderm, located right in front of area that forms heart, separates thorax from the abdomen, forms central tendon of diaphragm
Embryonic folding
Cranio-caudal (head-tail)
Transverse (lateral)
Happen at same time at end of week 4. Pinching of def yolk sac leads to gut tube. Tube within a tube
Gastroschisis
Incomplete folding, abdominal wall defect, intestines and other organs will herniate through the open hole
