Development of the NS Flashcards
What is the carnegie system?
A classification system of early vertebrate development into 23 stages for better comparison between species
Howmany germ layers does a human zygote have by embryonic week 3?
3
What is the neural plate?
The thick medial part of the ectoderm, aka. the neuroectoderm
What is neurolation?
The formation of the neural tube
What are the three primary brain vesicles called, and what do they develop into respectively?
Prosencephalon –> forebrain
Mesencephalon –> mesencephalon
Rhombencephalon –> pons, medulla oblongata and cerebellum
What are the secondary brain vesicles, and what do they develop into respectively?
Telencephalon
Diencephalon
Mesencephalon
Metencephalon –> pons and cerebellum
Myelencephalon –> medulla oblongata
What is a flexure?
A bending of the neural tube
Where does the mitosis take place?
Close to the ventricular system
What is the sulcus limitans?
- A functional border between the sensory- and the motor system
- Divides the alar- and basal plate
- The caudal part of thee neural tube
Describe the development of the spinal cord.
Sulcus limitans –> central canal
Alar plate –> dorsal horn
Basal plate –> ventral horn
Where does the proliferation during the development of the cerebellum take place?
The proliferation takes place on the outer layer
Describe the development of the telencephalon.
Develops as lateral evaginations from the prosencephalon
Describe the development of the diencephalon.
Develops as the medial part of the prosencephalon
Where does the retina develop from?
The diencephalon
What does the thin dorsal and superficial telencephalon give rise to?
The cerebral cortex
What does the thick ventral and deep telencephalon give rise to?
The BG
How does the hippocampus migrate in the human telencephalon?
By sulci formation
What does a neural stem cell give rise to?
Neurons, oligodendrocytes and astrocytes
Where are the microglia developed?
In the immunesystem (yolk sac) migrating to the brain
What are spina bifida?
An incomplete closure of the neural tube, can be caused by lack of folic acid
How are the developmental transcription factors regulated, and how are the expression pattern?
Regulation maintained by positive/negative feed back loops, tightly regulated
Expression pattern: regional
What does the HOX genes control?
Segmentation of the spinal cord and the hindbrain, and A/P fate
What is early pattering of the neural tube based on?
Simple combinations of gradients
How are the combination gradient of WNT in the neural tube?
The more caudal, the more WNT
