File:Stage 22 image 217.jpg

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Human Embryo Developing Cortex

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.

Cortex

Developing cortex will form from the thin outer layer called the cortical plate. The underlying layers transient structures that continue to supply cells to the cortex through fetal period, most of these layers will eventually be lost, except for a thin ventricular layer. Cells migrate out along radial glia that establish the initial columnar and layered structure of the cortex. Layers are named according to the nervous system revised terminology (1970)[1] A number of blood vessels can also be seen spanning the developing layers.

Ventricular Space

Developing ventricular space is cerebrospinal fluid (CSF) filled and the lateral ventricles form within the cortical region. The inset image shows lying within the lateral ventricles, the choroid plexus the modified vascular structure that forms and secretes the CSF.

Meninges

Developing meninges layers lie outside the neural tube. The thin pia mater that closely covers the entire brain. The mesh-like arachnoid mater and the sub-arachnoid space that will also be CSF filled. The dense dura mater lies outside these 2 layers and under the skull, it cannot be seen in the enlarged image.

Stage22 HPA2L.jpg

Low resolution image

Neural Tube Development
Neural Tube Primary Vesicles Secondary Vesicles Adult Structures
week 3 week 4 week 5 adult
neural plate
neural groove
neural tube

Brain
prosencephalon (forebrain) telencephalon Rhinencephalon, Amygdala, hippocampus, cerebrum (cortex), hypothalamus‎, pituitary | Basal Ganglia, lateral ventricles
diencephalon epithalamus, thalamus, Subthalamus, pineal, posterior commissure, pretectum, third ventricle
mesencephalon (midbrain) mesencephalon tectum, Cerebral peduncle, cerebral aqueduct, pons
rhombencephalon (hindbrain) metencephalon cerebellum
myelencephalon medulla oblongata, isthmus
spinal cord, pyramidal decussation, central canal
Links: Image - cortex overview | Image - cortex layers | Image - high resolution version | Cerebrum Development | Meninges Development


Note this section image is vertically flipped compared with original serial section images.

Selected Embryo Histology - Week 8 (Stage 22)  
Links: Carnegie stage 22 | Week 8


Stage 22 Links: Week 8 | System Development | Lecture - Limb | Lecture - Head Development | Lecture - Sensory | Science Practical - Head | Science Practical - Sensory | Science Practical - Urogenital | Historic - Skull Development | Carnegie Embryos | Madrid Embryos | Category:Carnegie Stage 22 | Next Stage 23
Week 8, GA week 10, 54 - 56 days, CRL 23 - 28 mm, Carnegie Embryos
  Historic Papers: 1914 | 1954 Stage 19-23
Carnegie Stages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | About Stages | Timeline
Week: 1 2 3 4 5 6 7 8
Carnegie stage: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
  1. <pubmed>5414696</pubmed>

Cite this page: Hill, M.A. (2024, March 29) Embryology Stage 22 image 217.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Stage_22_image_217.jpg

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G

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current02:09, 23 August 2011Thumbnail for version as of 02:09, 23 August 20111,200 × 820 (323 KB)S8600021 (talk | contribs)==Human Embryo Developing Cortex== * Week 8, Carnegie stage 22 * Note this section image is vertically flipped compared with serial original serial images. :Links: Neural System Development Cortex-with-section-insert-4.jpg (scan 35815 cropped and sc