1. Neurulation By Brett & Joshua

2. These slides will be uploaded after tonights session. Please see presenter notes under the slides for a description of the pictures. These slides will be uploaded after tonights session. Please see presenter notes under the slides for a description of the pictures.

3. Describe the formation of the morula and blastocyst and the process of blastocyst implantation Describe the process and resultant effect of gastrulation Describe the main derivatives of the 3 core embryonic tissues (endoderm, mesoderm and ectoderm) Describe the longitudinal and lateral folding of the embryo and describe the cavities, structures and regions that this create Describe the process and result of ‘reversal’ during folding Describe the process and result of neurulation (neural tube formation), how the notochord is involved and describe the range of defects that can occur Describe the origin of neural crest cells, their migration and the tissues that they form/contribute toward Explain the basic structure, content and arrangement of the pharyngeal arches and the outline the regions that they become (more of this in later blocks) Review the formation of the gut tube and the defects that can occur Objectives R G Tunstall 2013

4. What is neurulation? The formation of the neural tube, which later develops into the brain, spinal cord and retina

5. What are the three germ layers? Ectoderm Mesoderm Endoderm

6. From which germ layer does the neural tube derive? Ectoderm What else is derived from ectoderm? Skin

8. 5 3 1 2 4

9. Neural Crest Cell Migration Crest cells are involved in: Dorsal root ganglia Adrenal medulla Melanocytes Meninges (Arachnoid & pia) Autonomic nerve ganglia GI tract ganglia (Parasympathetic) Septation of heart Skull & face connective tissues Crest cells spread throughout body Re-differentiate into other cell types Defective neural crest cell migration – malformed face, nervous system absences, cardiac/gut defects ~ Day 21 ~ Day 19 Cells from neural crest migrate & form many important structures R G Tunstall 2013 DAMMAGeSS

10. Tube Closure Tube has two openings - at cranial end and at caudal end What are these called? Neuropores When does each close? Cranial day 25 Caudal day 27

11. Neural Tube Defects Prevention?

12. Neural Tube Defects

14. Any questions?

15. Labelling time!

16. Mini Quiz

17. What is neurulation? The formation of the neural tube, which later develops into the brain, spinal cord and retina

18. What embryological structure sends signals to initiate neurulation? Notochord

19. What is the region above the notochord called? Neural plate

20. The neural plate involutes to form the...? Neural groove

21. What is the name of the cells indicated by the black dots? Neural crest cells

22. Name THREE things the neural crest cells migrate and redifferentiate to become. [3] Crest cells are involved in: Dorsal root ganglia Adrenal medulla Melanocytes Meninges (Arachnoid & pia) Autonomic nerve ganglia GI tract ganglia (Parasympathetic) Septation of heart Skull & face connective tissues DAMMAGeSS

23. The neural tube longitudinally but is open at either end. What are these endings called? Neuropores

24. On what day does the cranial neuropore close? Day 25

25. On what day does the caudal neuropore close? Day 27

26. What is this called? Spina bifida occulta

27. What other feature might someone with spina bifida occulta have? Tuft of hair over region

28. What is this called? Meningiocoele

29. Myelomeningiocoele

30. How can spina bifida be prevented? Folic acid supplements during pregnancy

31. Thank you :)