Unit 1. Lec 9-Development of Nervous System Flashcards
When does the central nervous system start forming and what occurs?
- 3rd week as (thicken ectoderm) the Neural plate in the mid-dorsal region in front of the primitive node.
- Its lateral edge soon elevate to form the Neural folds
List Week 3 Key features
Nervous system first appears
- Neural plate
- Neural groove
- Notochord+paraxial mesechyme
- Neural tube
- Neural crest
Where is the neural plate located?
What does the lateral edges become?
- In front of the primitive node
- Lateral edges become neural folds
What does notochord and paraxial mescenchyme cause?
- Ectoderm to form to the neural plate
What does the neural tube form?
CNS
What does the neural crest form?
Forms the PNS and ANS
At week 4, the neural plate forms what?
Forms the neural tube and neural crest cells
- Neural tube cells become: CNS
- Neural crest cells become: PNS and ANS
What does the 2/3 of the Neural plate+ Tube become (as far caudal as the 4th pair of somite’s)?
HIGH yield
Future brain
What does the Caudal 1/3 of the neural plate and tube become?
HIGH yield
Spinal cord
What gives polarity to the embryo?
Primitive steak
What the neural folds, they fuse opposite of _ someite’s forming the neural tube
4th-6th somite’s (midline)
What does the fusion of neural folds create?
How it is structured?
Forming the neural tube that is open at both ends
- Cranial/rostral neuropore
- Caudal neuropore
When does the Cranial/Rostral neuropore close?
HIGH yield
around 25 days
When does the Caudal neuropore close?
HIGH yield
Around 27 days
What happens during spinal cord development that will decrease the neural canal size?
Lateral walls of the neural tube thickens
Initially what are the walls of the neural tube composed of?
Thick pseudostratified columnar neuroepithelium
For the spinal cord, proliferation and differentiation of the neuroepithelial produces what?
- Thick Walls
- Thin Roof and Floor Plates
What is the Sucus Limitans and what is its role?
Spinal Cord
HIGH yield
- Differential thickening of lateral walls
- FXN: Separates Alar and Basal plate
What does the Neuroepithelial Cells constitute?
Spinal cord
HIGH yield
- Ventricular zone (ependymal cells)
- Intermediate (mantle zone)
- Marginal Zone
What does the Intermediate (mantle zone) contain and what type of matter?
Spinal cord
- Contains Alar and Basal plates
- Gray matter
What does the Ventricular Zone give rise to?
Spinal Cord
Gives rise to all (in the spinal cord)
- macroglial cells
- neurons
What does the Marginal Zone consist of and what type of matter?
- Consists of outer parts of the neuroepithelial cells
- Becomes white matter
