Neuralation

Question 1

When does neuralation occur?

Answer 1

Begins at day 15 until day 28

Question 2

Describe the process of neuralation

Answer 2

1. Molecular signals from notochord (in mesoderm) tell ectoderm to differentiate in neural ectoderm.
2. This causes thickening of cells in midline (because these cells are closest to the notochord) to form neural plate
3. Lateral edges of neural plates become elevated to form neural folds.
4. Surface ectoderm move towards the midline above the folds, creating the neural groove.
5. Neural folds meet and fuse to form the neural tube under the surface ectoderm (the neural tube is internalised)

Question 3

What structures do neural crest cells become?

Answer 3

Peripheral nervous system, Schwann cells, melanocytes, endocrine cells, craniofacial structure, cardiovascular structure

Question 4

What 3 cell types does mesoderm differentiate into?

Answer 4

Paraxial (closest to notochord), Intermediate and lateral (furthest)

Question 5

Why does mesoderm differentiate into 3 cell types?

Answer 5

Because of the morphygian gradient (higher concn of molecular factor released by notochord goes to cells closest to it)

Question 6

What 3 structures does the paraxial mesoderm form?

Answer 6

1 Sclerotome
2 Dermomyotome
3 Myotome.

Question 7

Which structure becomes muscle?

Answer 7

Sclerotome and dermomyotome

Question 8

Which cell type forms intraembryonic coelom?

Answer 8

Lateral plate mesoderm

Question 9

What structure does the intra-embryonic coelom form?

Answer 9

Body cavities (Pleura, pericardium and peritoneum)

Question 10

What 7 cell types does lateral plate mesoderm further differentiate into?

Answer 10

1. Splanchnic
2. Somatic mesoderm
3. Splanchopleure
4. Somatic mesoderm
5. Somatic mesoderm
6. Somatopleure
7. Intraembryonic coelom

Question 11

What structures do splanchnic mesoderm form?

Answer 11

Heart and mandibular muscles

Question 12

What cell type forms the gut walls

Answer 12

Splanchnopleure

Question 13

What cell type forms the limb buds

Answer 13

Somatic mesoderm

Question 14

Which cell type forms the body wall?

Answer 14

Somatopleure