At the very earliest stages of development. All cells or equally capable of giving rise to an entire organism. But after only a few rounds of cell division. The cells begin to lose this pretty potent c and to differentiate sorting into groups that will be there contribute to the placenta or to the embryo itself. Speed cell embryo called a memorial out for its very like appearance. All cells express a pair of jeans CDX2 and OCT 3/4. But as the cells of the memorial go through the next round of division.
CDX2 his down-regulated in the innermost selves well popped three-four remains expressed throughout. The segregation of these genes is maintained as the sales continue to divide intel after about ten rounds of division. The embryo has become a hollow ball known as a blast assist. The outer layer of the blast assessed is made up in tyre live cells that express CDX2. This perfect under malaria will go on to become placenta. On the interior OPT3/4marks a small cluster of selves with phenomenal ability to differentiate. This inner cell mass is made up of cells with the developmental potential to give rise to all of the bodies many cell lineages, and ability known as tara potency, and indeed every one of the cells in your own body can't resist ancestry back to these few dozen for a potent stem cells.
The vast majority of the bodies trillions of cells are differentiated, meaning they have taken on specialized properties and functions and have lost the ability to generate sales of other types muscle, bone, and the nervous system are all made up of populations of differentiated cells. There is another type of self however that remains less differentiated and retains its ability to give rise to other cell types. These cells are known as stem cells. Stem cells exhibit two characteristics not found in more differentiated cells by definition stem cells are able to divide and make copies of themselves indefinitely a capacity known as self renewal.
This comes just power of division is not limited to creating more stem cells, however they can also give rise to a wide range of mature cell types. These unique characteristics make stem cells indispensable both for replenishing the body cells as they kate you know lost. And for constructing the body itself from a tiny number of cells during development.
Even after the embryo has grown into an adult many of the body cells continually die off and need to be replaced. For example, billions of red blood cells need to be replaced each day. This is the work of stem cells known as mata poetic stem cells which are located in the bone marrow residing in a complex senator environment
the come at a poetic stem cell is able to generate precursors to every type of blood cell, and indeed these stem cells have been used by physicians for decades
to replenish patients' blood supplies following radiation treatment for cancer. The stepwise differentiation of a stem cells progeny depends on combinations of
genetic and environmental factors that gradually stir these cells into following a specific lineage. This process involves different sets of stimulating factors operating in the sales environment at its surface membrane and within its nucleus.
Each step down the path draws you closer to becoming a functional red blood cell and entering the bloodstream. The lining of the small intestine turns over even faster than the blind at the microscopic level. This epithelia surface consists of billions of projections called velai with stem cell containing areas known as scripts
near their bases. The intestinal crypt contains slowly dividing stem cells that maintain their own numbers well also producing rapidly dividing progenitors. These transit amplifying sells churn out all of the differentiated cell types needed to migrate upwards and replace old ourselves as their shed from the tips of the velai. This constant self renewal by stem cells is a feature of many of the body systems including skin and bone.
Not all of the bodies organs regenerate as readily as the blood and the lining of the god. And the most important stem cells that have been identified in the adult body
are both limited in their ability to generate other lineages and difficult to maintain and culture. In contrast, the poor important cells of the inner cell mass can be harvested in grozny indefinitely in vitro, and can give rise to every type of cell in the body. These proposed in cells in culture are known as embryonic stem or you guess
cells. By culturing the cells under controlled conditions. It is possible to steer the differentiation into specifics cell types. For example, he has selves cultured on a bed of stromal feeder cells and treated with inductive factors such as b_n_p_ floor and sonic hedgehog tend to differentiate intramural lineages. By testing various kiev cell culture conditions. Scientists are gaining new insights into the biology of the differentiation processes that build and sustain and may one day be used to heal our bodies.
Stem cell researchers are currently exploring ways to differentiate yes sells into lineages that are of great medical and biological interest. The nervous system, the pen creates and the heart all regenerate tool poorly to restore themselves after serious injury or degenerative disease. Scientists are now in seeking ways of using the knowledge they gained everyday from the study of embryonic and some addicts themselves to help save patients lives and to improve our understanding of their
seemingly limitless potential.
