Ch. 5: Development of the Nervous System Flashcards
When does the Preembryonic stage take place?
What do you look like during this time?
- Conception to 2nd week of gestation
- A disk that will become you
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/587/106/a_image_thumb.png?1659468355)
When does the Embryonic stage take place?
2nd to 8th week of gestation
What transformations happen in the Embryonic Phase?
- Organs begin to form from embryonic disk
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Ectoderm: Neural
- Sensory organs, epidermis, nervous system
-
Mesoderm: Bony
- Dermis, muscles, skeleton, excretory system, circulatory system
-
Endoderm: Gut
- Gut, liver, pancreas, respiratory system
-
Ectoderm: Neural
- Neural tube forms and closes
- Brain begins to form
When is the Fetal Phase?
8th week gestation until birth
What happens in the Fetal Phase?
- Brain formation continues
- Myelination begins
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/587/387/a_image_thumb.png?1659468357)
What are the phases of Nervous System Formation?
- Phase 1: Neural Tube Formation
- Phase 2: Initial Brain Formation
What is the Neural Plate?
Neural cells, flat - needs to round out to form
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/587/664/a_image_thumb.png?1659468359)
What is the Neural Groove?
Forms as outside of disk begins to mound up
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/587/703/a_image_thumb.png?1659468360)
What is the Neural Tube?
What was flat has now rounded up to form a circle
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/587/758/a_image_thumb.png?1659468361)
What are Neuropores?
- Rostral and Caudal openings of neural tube (not yet closed)
- Failure to close: can cause Spinabifida or Anencephaly
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/587/778/a_image_thumb.png?1659468363)
What is the Neural Crest?
- Pockets of cells at edgs where disk mounds up
- Form outside of closed tube & dorsal root ganglion
- Morphology: pseudo-unipolar
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/785/654/a_image_thumb.png?1659468489)
What is the Mantle Layer?
- Inner Ring
- Nervous System cell bodies
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/785/985/a_image_thumb.png?1659468490)
What is the Marginal Layer?
- Outer ring
- Axons and glia
- Non-neural support cells when tube closes
- Protective ring around neurons
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/786/233/a_image_thumb.png?1659468491)
What is a Somite?
What develops from it?
- Somite (mesoderm): small balls, 31 on each side, becomes:
- Sclerotome: vertebrae & skull
- Myotome: skeletal muscle
- Dermatome: skin
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/786/483/a_image_thumb.png?1659468493)
What 2 plates form from the Mantle Layer Divisions?
What do these plates control?
- Motor Plate → motor neurons → ventral horn → becomes Myotome (innervated by 1 segmental spinal nerve)
- Association Plate → interneurons and sensory neurons → dorsal horn → Dermatome
![](https://s3.amazonaws.com/brainscape-prod/system/cm/150/786/641/a_image_thumb.png?1659468494)