File:Stage 22 image 217.jpg

• Human embryo, Week 8, Carnegie stage 22.
• Section from the neural tube at the level of the developing cortex.
• Inset (upper right) shows section overview and approximate level of section (red line).
• Developing cerebrum layer thicknesses are shown in microns.

The thin layer outer called cortical plate will eventually form the adult brain cortex. The other underlying layers are part of the development process and will continue to supply cells to the cortex through fetal period, these layers will eventually be almost completely lost. Layers are named according to the nervous system revised terminology (1970)^[1]

The ventricle is the CSF fluid-filled space within the brain. The inset image shows lying within the ventricles, part of the choroid plexus that forms and secretes the CSF.

Outside the developing cortex the developing brain meninges pia and sub-arachnoid layers can also be seen.

Low resolution image