Stem Cells

Stem cells The human body is composed of different cells and tissues but these stem cells are the source for every tissue and organ in the body. A stem cell can easily be differentiated from all other cells in the body by its ability to renew. It can be divided into much more similar cells.  The most important function of these stem cells is that they can repair and replace the tissues available in the human body. These cells have strong healing power. For example- When we get injured, stem cells available in our muscles repairs all the damaged tissues in few days. Also, these cells have the exceptional potential to evolve into any type of cell.

Cells which starts in the embryo as unprogrammed cells, developed well to create muscle, bone, skin, heart, brain and various types of cells are known as pluripotent stem cells.

Types of cells

  • Embryonic stem cells.
  • Tissue-specific stem cells.
  • Induced pluripotent stem cells.
  • Mesenchymal stem cells.

Embryonic Stem Cells

Embryonic Stem CellsThese cells are acquired from blastocyst’s inner cell mass. It is mainly a hollow ball of different cells in a human within 3 to 5 days after the fertilization of an egg cell by a sperm. In humans, the size of the blastocyst is just like a single dot.

The cells found inside the inner cell mass gives rise to the specialized cells that will then give rise to all the tissues and organs of the human body. When extracted in the laboratory in special conditions, retains the property of embryonic stem cells.

Embryonic Cells are also known as pluripotent as they can give rise to the all the different cell types in the body, but not the umbilical cord and placenta. These cells are very beneficial as they provide a renewable source for testing therapies and drugs and for studying disease and normal development.

The Embryonic stem cells are derived initially from blastocyst formed by in vitro fertilization for assisted reproduction.

Tissue-specific Stem Cells

Tissue-specific stem cells are also known as somatic stem cells and are known to be more specialized than Embryonic stem cells. There are some tissues and organs in the body that contains small caches of tissue-specific cells that helps in replacing cells from all those tissues that are lost due to any type of injury or disease in day-to-day life.  It is difficult to find out the tissue-specific stem cells in the human body as these cells don’t have potential to renew themselves as embryonic cells have.

Induced Pluripotent Stem Cells

Pluripotent Stem CellsThese cells have been tested and arranged by converting tissue-specific cells into embryonic cells in the lab. These cells are accepted as an important tool to learn about normal development, onset and progression of the disease and also helpful in testing various drugs. These stem cells share the same characteristics as embryonic cells do. They also have the potential to give rise to all the different cell types of human body.

Mesenchymal Stem Cells

Mesenchymal Stem Cells

These cells are mainly isolated from the connective tissues surrounding other tissues and organs known as stroma. These mesenchymal stem cells are accurately called as stromal cells by various scientists. The first mesenchymal stem cells were found in the bone marrow and are capable of developing bones, fat cells, and cartilage. There are different mesenchymal stem cells that have stem cells and are being used for various diseases as they have been developed from different tissues of the human body. The characteristics of mesenchymal stem cells depend on the body from where they come.

Sources of Stem Cells

Now the question is, from where these stem cells come from? Stem Cells are formed at different times and come from different parts of the body. Adult stem cells can be found in specific tissues in human body. Matured Cells are specialized to conduct various functions. Generally, these cells can develop the kind of cells found in tissues where they reside.

Embryo Stem Cells are derived from 5-day old blastocysts that are precursors to embryos and are pluripotent in nature. These cells can develop any type of cells and tissues in the body. These cells have the potential to regenerate all the cells and tissues that have been lost because of any kind of injury or disease.

Stay tuned with Byju’s to learn more about Stem cells

Practise This Question

Identify the process where root pressure is not involved -
A. Oozing out of sap from the cut end of stem.
B. Loss of water vapor from the aerial parts of plant.
C. Reestablishment of continuity of water column in the xylem which often break due to tension.
D. Water loss in liquid phase from vein endings of leaves.