干细胞是无专门的细胞，有可能发育成体内任何类型的细胞. This makes them a valuable resource for medical research and potential treatments for a variety of diseases. 可以从多种来源获得干细胞, 包括胚胎, 脐带血, 和成人组织.
干细胞的起源
Stem cells are derived from the inner cell mass of a blastocyst, which is a very early embryo. The inner cell mass gives rise to all of the tissues and organs of the body. Stem cells are also found in the umbilical cord blood, which is the blood that flows through the umbilical cord from the fetus to the mother.
干细胞来源
干细胞有两种主要类型: 胚胎干细胞和成年干细胞. 胚胎干细胞来自胚泡的内部细胞质量, 而成年干细胞在整个身体的各种组织中发现. Adult stem cells are more limited in their potential than embryonic stem cells, but they are easier to obtain and less controversial.
胚胎干细胞
胚胎干细胞是多能的, which means that they have the potential to develop into any type of cell in the body. This makes them a valuable resource for medical research, as they could potentially be used to treat a wide variety of diseases. 然而, embryonic stem cells are also controversial, as they are derived from embryos that are destroyed in the process of obtaining the cells.
成年干细胞
成年干细胞是多功能的, which means that they have the potential to develop into a limited number of cell types. 然而, adult stem cells are more readily available than embryonic stem cells, and they are not controversial. Adult stem cells have been used to treat a variety of diseases, 包括白血病, 淋巴瘤, 和镰状细胞贫血.
Stem cells are a valuable resource for medical research and potential treatments for a variety of diseases. 然而, the ethical issues surrounding embryonic stem cells have led to a search for alternative sources of stem cells. Adult stem cells are a promising alternative, as they are more readily available and less controversial than embryonic stem cells.