Across
- 2. a _____-ended forgut and hindgut form during the development of the head process. The endoderm is reflected ventrally, folding around to mirror neural tube formation. Figure 5.
- 5. labelled t. _________ mesoderm. Part of lateral mesoderm
- 8. labelled s. _________ mesoderm. Part of lateral mesoderm
- 12. (2 words) structure that the neural plate (thickened ectoderm above notochord) forms when is forms a depression. Labelled U.
- 13. labelled M. Rod shaped aggregate of cells located cranially to the primitive streak within the coelom not occupied by mesoderm. This structure induces formation of head, nervous system and somites. Eventually becomes part of intervertebral discs.
- 16. aka primary mesenchyme. The majority of cells that migrate through the primitive streak. Has 3 regions – paraxial, intermediate and lateral regions. eventually a coelom is reformed within the LATERAL ________ , and the LATERAL ___________ splits into two layers (somatic (outer) and splachninc (inner)). Labelled J.
- 18. epithelium derived from the mesodermal layer which lines body cavities formed by the lateral mesoderm.
- 20. (2 words) labelled K. A depression between a pair of ridges on the surface of the epiblast, through which epiblast cells migrate to form mesoderm and endoderm.
- 24. the lateral mesoderm fuses with the endoderm (splanchopleure) and ectoderm (somatopleure) with a coelom between. This coelom goes on to form BODY __________ (pleural, peritoneal and pericardial). Lines by mesothelium (epithelium derived from the mesoderm)
- 29. the endoderm forms ___________ lining of the gut, respiratory tract, bladder, and midder/outer ear. As well as parenchyma of glands such as the liver, pancreas, thyroid and parathyroid.
- 30. the ridges of the neural plate fold around to form the neural ____ (labelled V), which separates from the overlying ectoderm. This structure becomes the central nervous system.
- 31. _____ buds develop (labelled Y , figure 6)
- 33. notochord induced transformation of ECTODERM cells into neural tissue. Begins cranially (brain region) progresses caudally.
- 34. the intermediate mesoderm contributes to the _______ and reproductive systems.
Down
- 1. (2 words) formed by the hypoblast. Also known as the primitive gut. See fig 2, labelled E.
- 3. the separation of the hypoblast layer from the epiblast (previously the inner cell mass / embryonic disc). (labelled H) Establishes a fluid filled _______. This becomes temporarily filled with mesoderm when epiblast cells along the primitive streak migrate through to establish start of mesoderm and endoderm. (migrating mesoderm labelled J)
- 4. under the influence of neural crest cells and neural tube cells, some ectodermal cells form discrete thickenings called ___________. Include nasal, lens and otic ________.
- 6. the primitive streak defines the _________________ axis of the embryo
- 7. surface ectoderm at the cranial end of the embryo grows dorsally and folds down to form a ____ process. An identical mechanism occurs at the caudal end, forms tail process. Folds eventually meet at umbilicus.
- 9. the trophoblast layer on top of the thickened inner cell mass layer (embryonic disc) ____________ around the same time as the hypoblast is forming (labelled F).
- 10. somites (from the paraxial mesoderm) comprise the majority of structures in the axial skeletal, muscles, and _______ (deep skin layer/connective tissue).
- 11. (2 words) labelled L. Structure from which the notochord forms.
- 14. once the endoderm and mesoderm cells have migrated through primitive streak, the remaining outer layer of cells (epiblast) is known as the ____________, which goes on to form nervous system and skin epidermis. Labelled O.
- 15. paraxial mesoderm thickenings on either side of the notochord. Labelled X. Divided by fissures into blocks known as ___________
- 17. the first _________ somitomeres contribute to mesodermal structures in the head (muscles of jaw, face, pharynx and larynx). After these ________, they are known as somites, organised into discrete blocks.
- 19. the _______ bulge becomes apparent (figure 6, labelled X).
- 20. (2 words). Labelled Z (figure 6) ____________ ________ are derived from neural crest cells. surface ectoderm evaginates between them to form clefts, and endoderm evaginates to form pouches on the inside.
- 21. ______________ mesoderm. Labelled Q. Goes on to form urogenital system.
- 22. initial cells that migrate through the primitive streak join the hypoblast (surrounding the yolk sac) these cells form the ____________ layer (labelled N)
- 23. following gastrulation, the embryonic disc fold into a ______ layered tube.
- 25. _______ mesoderm. Labelled R. Splits into two layers, somatic (attached to ectoderm) and splanchnic (endoderm side), with a coelom between. The ______ mesoderm eventually forms parts of the heart.
- 26. neurulation begins in the __________ region, and progresses caudally into the region of the spinal cord.
- 27. a layer of cells formed by proliferation and migration of the inner cell mass. This eventually delaminates (detaches from the inner cell mass) see figure 2. Labelled G. And forms the yolk sac (primitive gut). The embryonic disc / inner cell mass is now known as the EPIBLAST.
- 28. cells that have migrated to the lateral border of the neural tube are neural ______ cells (labelled W). these cells form a huge range of structures from pigment cells in skin, to adrenal medulla cells, to meninges, to teeth.
- 32. _______ mesoderm. Labelled P. Goes on to form somites. – skeleton and skeletal muscle.