Nervous System Development Flashcards
primordial dilation’s of the neural plate (cranial end)
called the primary brain vesicles
F= prosencephalon (fore-brain)
M = Mesencephalon (mid-brain)
H = rhombencephelon (hind brain)
where does the spinal cord develop?
below the level of the hindbrain
primordial dilations aka
primary brain vesicles
neuroepithelial layer
-derived from and characteristic
initially the wall of the neural tube is formed from the neuroepithelial cells and these divide and form a THICK pseudostratified epithelium called neuroepithelium layer
cytodifferentiation of the brain and spinal cord
neuroepithelial layer is proliferating and forming a thick pseudostratified epithelium and as a result we have neurogenesis and gliogenesis
when is neurogenesis more prominent?
during embryonic development
ventricular cells
cells that form the brain and spinal cord
ventricular zone
inner layer of developing spinal cord AND WILL GIVE RISE TO ALL NEURONS AND MACROGLIAL CELLS
inner layer
ventricular zone - which lines the canal and gives rise to other layers
these are remaining cells of the ependyma
ependymal cells
these cells line the central canal of the spinal cord and ventricles of the brain
Intermediate zone
mantle zone
- formed by neuroblasts
- becomes the gray zone/material of the spinal cord
outer layer
marginal zone
- formed by neuronal processes that give rise to the white matter of the spinal cord
T/F microglial are derived from the ventricular zone of the neural tube
FALSE
They are a macrophage - so mesenchymal
three types of glial cells and where they arise from
- Macroglia-oligodendrocyte - from gliablast (from neuroepithelial cells differentiated)
- Macroglia- Astrocytes (from the glialblast - from the neuroepithelial cell)
- Microglia*NOT DERIVED FROM NEUROEPITELIAL CELLS - from resident macrophage of the bone marrow so it is mesenychmal in origin
macroglia
providing nutrition, physical support, and synthesizing myelin
- includes the oligodendrocytes and astrocytes
dorsal root ganglion
DERIVED FROM THE NEURAL CREST CELLS
These are sensory cells that give rise to the cell body of the sensory neuron that is housed in the dorsal root ganglion
This is in the PNS.
schwann cells are originated from?
neural crest cells and produce the myeline for the PNS
Differentiation in the spinal cord
Ventral thickening - basal plates = motor horn cells
Dorsal thickening = alar plates= sensory area
Sulcus limitans= groove on each side that separates alar from basal
Roof and floor plates = no neuroblasts, pathway for nerve fibers to cross from one side to the other
roof and floor plates
no neuroblasts, pathways for nerve fibers crossing to the contralateral side
sulcus limitans
a groove on each side that separates the a from basal
marginal zone
white matter, so AXONS from the cell bodies in the brain, spinal cord, and dorsal root ganglion
where do the cell bodies of the ventricular zone end up?
intermediate zone or mantle zone, what is left over differentiates into the epedyma cells and lines the central canal of the spinal cord and the ventricles of the brain
alar plates
DORSAL gray horns with sensory/afferent
differentiate into inter neurons and receive first input from the sensory neurons of the peripheral nervous system
basal plate
ventral/motor/efferent
differentiates into voluntary motor neurons to innervate skeletal muscle
