Powerpoint 5 Flashcards
during embryonic development, what day does the Morula form?
about day 4
during embryonic development, on what day do the cells separate into two groups?
about day 5
Cells of the inner cell mass differentiate into the outer ______ and inner _________
epiblast, hypoblast
What three layers form in the embryonic neural tube?
- Ventricular zone (germinal layer)
- mantle layer (intermediate zone)
- Marginal layer (outer zone)
The ventricular zone, the first zone for forming the neural tube, leads to…
ependymal cells
The mantle layer leads to…
“gray matter” of the CNS
The marginal layer leads to…
“white matter” of the CNS
What do ependymal cells form?
epithelial layer that lines the brain and the spinal cord
True or false:
Gray matter in the CNS has axons
False!
Gray matter has neural cell bodies such as glial cells and astrocytes
Are the axons in the white matter of the CNS myelinated?
Yes
In which of the three layers that form the embryonic neural tube would you find stem cells?
The Ventricular layer
When is neurogenesis most active?
during embryonic development
What is responsible for producing different types of neurons?
neurogenesis
What type of stem cells are derived from the neural tube?
Neural stem cells (NSCs)
What are two characteristics of Neural Stem Cells (NSCs)?
- They are self-renewing, multipotent cells
- They generate all neural cell types that grow and differentiate into neurons and glia cells during embryonic development
What are the two main types of neural stem cells?
- Neuroepithelial cells
- Radial glial cells
What do radial glial cells do?
- produces neurons in the brain
- radial migration occurs
What is another name for Neural Stem Cells (NSCs)?
neuroepithelial cells
The three phases of neurogenesis/cortical development are?
- Expansion
- Neurogenic
- Astrogenic
The creation of more neural precursor cells occurs in which phase of cortical development?
the Expansion phase
What type of division can be observed in the expansion phase of cortical development?
symmetrical
Which type of division can be observed in the neurogenic phase of cortical development?
asymmetric
What is another name for the astrogenic phase?
Gliogenic phase
True or False:
Radial cells can divide
True!
they can produce more radial glial cells, neurons, and neuronal progenitor cells
What process regulates the length of each phase and the change from one phase to the next?
Gene Expression
Are neurons produced in the astrogenic phase?
NO! cell divisions produce glial cells and not neurons
What is Notch?
A transmembrane glycoprotein that affects cell-cell interactions and binds to ErbB receptors
Notch expression stars what phase?
the neurogenic phase
What promotes neuron to glia transition?
Fgf 9
True or False:
the neural plate initially develops into three brain vesicles and later develops into five
true
What are the names of the three initial brain vesicles?
- Prosencephalon
- Mesencephalon
- Rhombencephalon
the prosencephalon (forebrain) is composed of…
the telencephalon and diencephalon
the rhombencephalon (hindbrain) is composed of…
the metencephalon and the myelencephalon
