Download Embryological Development

Embryological Development
and Stem Cells
By:
Jewel Reuter, LA Virtual School
Donald Cronkite, Hope College
Attachment #12
Two Kinds of Cells
During embryological development, cells
divide again and again.
Eventually, however, cells differentiate.
Most differentiated cells do not divide.
But if no cells divided…
Some cell division is always necessary to
Make more blood cells
Heal wounds
Make a continuous supply of sperm cells
So there are stem cells. . .
Stem cell keeps
dividing
differentiate
Bgn1
In early embryos, most cells are
stem cells.
Inner cell mass
(becomes the embryo)
Compared to the more
than a trillion cells in an
adult, the inner cell mass
is scarcely 100 cells.
The inner cell mass
must give rise to many
different cell types. All
the inner cell mass is
made of stem cells.
The blastocyst:
A week-old
embryo
This membrane of cells attaches
the embryo to the mother.
Bgn2
Stem cells vary in what they become.
Embryonic stem cells:
Adult stem cells:
Can become any cell
Can become a few cell types
(Inner cell mass of
blastocyst)
(Blood-forming, woundhealing, sperm-forming cells)
Bgn3
Stem cells can be cultured.
With the right medium,
stem cells can be
cultured in dishes.
Scientists are learning
how to get a stem cell to
differentiate into a
certain cell type.
What could we do with stem cells?
Diabetes – cells of the pancreas
Parkinson’s disease – cells of the
brain
Many diseases are due to
cells that won’t work.
The “bubble boy” – cells of
the immune system
What could we do with stem cells?
Diabetes – cells of the pancreas
Parkinson’s disease – cells of the
brain
What if we could replace
the cells that won’t work
with new ones made from
stem cells?
The “bubble boy” – cells of
the immune system
This is the end of this lesson,
but not the end of your learning.
ADV1
In early embryos, most cells are
stem cells.
Inner cell mass
(becomes the embryo)
Compared to the more
than a trillion cells in an
adult, the inner cell mass
is scarcely 100 cells.
So, the inner cell mass
must give rise to many
different cell types. All
of the inner cell mass is
made of stem cells.
The blastocyst:
A week-old
embryo
Trophoblast
(becomes part of placenta)
ADV2
Stem cells vary in what they become.
Totipotent stem cells
(the inner cell mass of
blastocyst) can become
any cell.
Pluripotent stem cells can
become a few cell types, such
as blood-forming, woundhealing, sperm-forming cells.
ADV3
Stem cells can be cultured.
With the right medium,
totipotent or pluripotent
stem cells can be
cultured in dishes.
Scientists are learning
how to get a stem cell to
differentiate into a
certain cell type.