Development of Nervous system Flashcards
At the beginning of the 3rd week, ectoderm thickens to form the ________
neural plate
Fusion of neural folds begins in the ________ and proceeds in cephalic and caudal directions. At the end of this fusion, the cranial and caudal neuropores are visible
5th somite
The cells that form the early neural tube are called the ___________
Neuroepithelial cells
Once the neuroblasts are formed, they lose their ability to divide. They start arranging themselves in different layers thus giving rise to: ___________ and ___________.
Mantle layer; Marginal layer
Below the mantle and the marginal layers- the __________ still exists
neuroepithelial layer
As a result of myelination of nerve fibers, the marginal layer appears white and is called the ___________
white matter of the spinal cord.
Dorsal alar plates form the ??
Sensory areas
Ventral basal plates form the ??
motor areas of the spinal cord
marks the boundary between the Alar and the Basal plates
Sulcus limitans
What are the 3 neuroblast types?
Apolar
bipolar
Neuropolar
Neuroepithelial cells can differentiate into?
Neuroblasts or Glial cells
Neural crest cells originate from the __________
Neural Folds
Neural crest/Neural tube or neural tissue originally came from the _________-
ectoderm
What forms after the neuroblasts stop forming?
Gliablasts
Ependymal cells secrete what?
CSF
phagocytic in nature formed from monocytes are?
Microglia
Gliablasts can give rise to what 3 tissues?
Oligodendroglia, Fibrillar astrocyte (white matter), & Protoplasmic astrocyte (Grey matter)
Cells of the dorsal root ganglia form two processes. What are they?
Central process
Peripheral process
considered to be the 4th germ layer of the body
Neural Crest Cells
In the spinal cord, the central process ends in the dorsal horn or ascend through the marginal layer to one of the higher brain centers. These processes are known collectively as the ________________________
dorsal sensory root of the spinal nerve
The peripheral process join the ventral motor roots and participates in formation of the _________
trunk of the spinal nerve
The cephalic end of the neural tube shows three dilations. the three primary brain vesicles. What are they?
Prosencephalon, or forebrain
Mesencephalon, or midbrain
Rhombencephalon, or hindbrain
The neural tube forms two flexures. What are they?
Cephalic flexure in the midbrain region
Cervical flexure at the junction of the hindbrain and the spinal cord
The telencephalic vesicles, following the development of the optic vesicles, turns into the telencephalon. This develops the what?
Cerebral hemispheres
the optic cup makes the ?
Retina and optic nerve
The cavities of the telencephalic vesicles become the _____?
lateral ventricles
The posterior part of the forebrain becomes the __________?
diencephalon
The cerebral hemispheres are in communication with the third ventricle through ________________
Foramen of Monro (interventricular foramen)
Formed by neuroblasts from the alar and the basal plates migrating into the marginal layer
The colliculi
The primordia develop into the
Superior and inferior colliculi
The pontine flexure causes the roof plate to depress, flattening the entire structure out and the ___________ is formed.
Fourth Ventricle
Basal plates give rise to _______ neurons
motor
Alar plates give rise to ______ neurons
sensory
