Stem cells are primitive cells,which have 2 main properties,
A. They have the capacity for self renewal
B. They can be coaxed into multilineage differentiation.(like RBCs,cardiomyocytes etc.)
Stem cells exist in both embroys and adult tissues.
In embryos,they perform organogenesis.
In adults,they normally function to replace worn out cells.
But,what is new about them is that,
1. They exist in almost all adult tissues in copious amount.
2.They can be harvested and grown in laboratories to transdifferentiate into desired lineage.
3. Transfused stem cells have got the ability to travel to their desired site of action.
some important sources of stem cells are as follows,
1.Bone marrow stem cells i.e the hematopoetic stem cells can also be collected from umbilicus and used to treat different hematologic malignancies.
2.Neuronal stem cells they can be used to treat different neurodegenerative disorders.
3.Islet stem cells are under clinical trial for using in type 1 Diabetes Mellitus.
4.Adult eye stem cells located in the region of limbus(sclerocorneal junction)
5.Liver stem cells present in the canal of Hering,can be used to treat fulminant hepatitis.
6.Intestinal stem cells present in the crypts,which forms villi
7.Skin stem cells located in the region of hair follicle and sebaceous glands,which contribute to repair the damage of epidermis.
SOURCE:TEXT BOOK OF PATHOLOGY:IVAN DAMJANOV