Wk 4.1 Neurodevelopment Flashcards
What is Gastrulation?
Involves the movement of cells from the outer surface of the embryo to its inside.
What are three cell layers of the embryo?
-Endoderm – inner layer – gut, liver and lungs
-Mesoderm – middle layer – connective tissue, muscle and vascular system
-Ectoderm – outer layer – Central and peripheral nervous system, skin
What is neurulation?
The process by which the neural tube is formed.
What are the neural tube defects?
-Spina bifida cystica
-Myelomeningocele- type of SBC
- Meningocele
- When does Cell proliferation happen?
2.When does asymmetric division occur?
1.Embryonic Day 28-42 - cells are proliferating symmetrically
- After day 42 - asymmetric division occurs
What is the term for back-front and top-bottom
Back-front =Dorsoventral axis
Top-bottom=Rostrocaudal axis
What are the three stages of Rostrocaudal patterning?
-Wk4 Anterior is specialist into 3 distinct regions
-Wk6 Anterior specialised into 5 distinct regions
-Wk11 Cerebrum has grown more rapidly
1.When does neurulation happen?
2.What happens?
- Happens in week 4 post conception
- Ectoderm layer thickens and flattens making a neural plate , which arises within the ectoderm layer
What happens in the neurodevelopment of the neural plate?
- After separation of the neural plate from the rest of the laters the ends of the neural plate push up against each other forming a v like fold
-Folds completely make a neural tube due to fusion forming spinal cord and Brain
-Development progresses many proliferative area surrounding the ventricle middle, which undergoes asymmetrical division causing the neural stem cells or epithelia cells to regenerate many forms of itself making a bigger one
What happens in neurogenesis?
- Neurogenesis happens 8 wk- 20wk gestation
-Neural stem cells become mature neurons
What area is surrounds the ventricles?
-Ventricular zone
- Subventricular zone
What doe the norodonal secrete?
Growth factors
What does lack of folate cause?
No closing of the anterior and posterior causing neural defects
What are the three regions of the neural tube?
- Prosencephalon - Forebrain, (Cerebral Cortex)
-Mesencephalon - Midbrain (Basal Ganglia and Thalamus)
- Rhombencephalon - Hindbrain
(Brain stem and Cerebellum)
What is the migration?
-Newly born immature neuronal cells migrate along radial glia
-Migrate from ventricular layer up through cortex
-Creates a radial inside-out pattern of development
