Lecture 2. Early Development of the Nervous System Flashcards
A plastic (changeable) living organ that
continuously changes in response to your ongoing
experiences.
Brain
a single cell formed by the amalgamation of an ovum (an egg) and a sperm.
Zygote
Zygotes divides to form?
It divides to form two daughter calls; these two divides until a mature organism is
produced.
If the zygote only develops by the division to form daughter cells, we will end up into?
an amorphous mass of
homogeneous cells.
To save from the fate of being an amorphous mass of homogenous celss, what are three things must occur other than cell multiplication?
(1) cells must differentiate
(2) cells must make their way to
appropriate sites and align
themselves with the cells around
them to form particular structures
(3) cells must establish appropriate
functional relations with other cells
4 EMBRYONIC STEM CELLS
Totipotent, Pluripotent, Multipotent, and Unipotent
The cell has the ability to develop into any class of cell in the body (e.g neuron, bone, skin, or heart cells)
Totipotent
After cell division,
developing cells have the
ability to develop into
many, but not all,
classes of body cells
Pluripotent
As the embryo develops,
new cells become more
and more specialized,
and eventually the new
cells can develop into
different cells of only
one class (e.g., different
kinds of blood cells).
Multipotent
Can develop into only one type of cell (e.g., bipolar neurons)
Unipotent
Five Phases of Early Neurodevelopment
- induction of neural plate
- neural proliferation
- migration and aggregation
- axon growth and synapse formation
- neural death and synapse rearrangement
In this phase of early neurodevelopment, the tissue that is destined to develop into the human nervous system is recognizable as neural plate
Induction of the Neural Plate
A small patch of extodermal tissue on the dorsal surface of developing embryo
Neural Plate
The first major stage of Neurodevelopment in all vertebrates
Neural Plate
How the development of the neural plate works?
Is induced by chemical signals from an area of an underlying mesoderm layer - an area consequently referred as organizer