Term
| At beginning of 3rd week teh developing embry exists as two layers ________ |
|
Definition
|
|
Term
|
Definition
| Formation of the primitive streak that appears on the surface of the epiblast |
|
|
Term
|
Definition
The process whereby cells of the epiblast migrate toward the primitive streak, detach from teh epiblast and slip beneath it |
|
|
Term
| Invaginating cells of the epiblast create |
|
Definition
|
|
Term
| Non-invaginating cells (remaining cells of epiblast) become |
|
Definition
|
|
Term
|
Definition
Endoderm cells in the midline of the embryo proliferate and detach from teh endoderm to form a solid cord of cells - notochord basis for axial skeleton |
|
|
Term
| What is the initial event in the process of neurulation |
|
Definition
| notochord induction of overlying ectoderm to thicken and form neural plate. Cells of neural plate make up neuroectoderm whose induction represents the inital process of neurulation |
|
|
Term
|
Definition
| Process by which a portion of the embryonic ectoderm folds up to form a neural tube |
|
|
Term
| Neural plate formation is induced by________ |
|
Definition
|
|
Term
|
Definition
| ectodermal cells that differentiate into a thick plate of pseudostratified, columnar neuroepthelial cells as a result of neural induction. |
|
|
Term
| Neural plate folds to form the neural tube at the ___ week for development |
|
Definition
|
|
Term
|
Definition
| neuroepithelium and adjacent surface ectoderm |
|
|
Term
|
Definition
| groove surrounded by the neural plates |
|
|
Term
|
Definition
| the neural tube deepsn and the neural folds approach each other and begin to fuse. |
|
|
Term
| Neural tube formation begins on day...... |
|
Definition
| 22 in teh regions of the future occipital and cervial spinal cord and proceeds rostrally and caudally |
|
|
Term
| Anterior Cranial Neuropore |
|
Definition
| Cranial opening => closes about day 24-25 |
|
|
Term
| Posterior (caudal) Neuropore |
|
Definition
| caudal opening closes about day 26-27 |
|
|
Term
| As the neural tube closes, cellular rearrangement results in the formation |
|
Definition
Roof Plate of the Neural tube Surface ectoderm |
|
|
Term
|
Definition
The process by which the neural tube in the tail bud is formed. This becomes the sacral adn coccygeal portiosn of hte spinal cord. It involves the condensatiosn of tail bud cells into medullary cord. The medullary cord undergoes cavitation to form a lumen which quickly merges with the neural canal of the more cranial neural tube . Process completed at 8 weeks of development |
|
|
Term
|
Definition
| closed tubular structure with a narrow caudal portion- prdt of closure of neuropores and complete of neurulation. |
|
|
Term
|
Definition
| the broader cephalic portion of the closed neural tube characterized by a number of dialations |
|
|
Term
|
Definition
| groups of cells from teh top of each neural fold that dissasociate and form a variety of cell types including the ganglia of spinal nerves, postganglionic autonomic neruons and Schwann cells fo the PNS. |
|
|
Term
| Neural Tube defects (NTD) |
|
Definition
| when neurulation fails to occur normally. |
|
|
Term
| NTDs arise at weeks ______ of gestation |
|
Definition
|
|
Term
|
Definition
| dysraphishm - entire lenght of the nural tube opens onto the surface of the head and back. |
|
|
