Células madre

If you would like to see more scientifically accurate 3D medical images, please subscribe to our channel:    / nucleushealthvideose   MEDICAL ANIMATION TRANSCRIPT: The human body contains organs such as bones, the brain, the heart, and the reproductive organs. The basic cells that give rise to all the different cells in these organs are called stem cells. One type of stem cell is a woman's egg cell that has been fertilized by a man's sperm. This single cell, called a zygote, is the first cell of a developing human being. It is also called a totipotent stem cell because it can form any type of cell in the body, as well as the umbilical cord and placenta. After a zygote divides several times, it becomes an early-stage embryo called a blastocyst. Embryonic stem cells come from the cells found inside the blastocyst. They are pluripotent. This means they can form any type of cell in the body, except for umbilical cord cells and placental cells. In the laboratory, embryonic stem cells are donated from surplus embryos created during in vitro fertilization (IVF). IVF is a procedure that helps women become pregnant. Another type of stem cell is an adult stem cell. Small groups of these cells are found in some organs, such as the skin, after birth or in adulthood. Adult stem cells are multipotent. This means they can only develop into a few different cell types related to the organ in which they are found. For example, the skin contains a small number of adult stem cells that can divide to create new adult skin stem cells or can develop into more specialized stem cells to replace those lost due to cellular aging or damage. In the laboratory, scientists can now induce, or cause, a regular body cell, such as a skin cell, to transform into a pluripotent stem cell. Like embryonic stem cells, these induced pluripotent stem cells can develop into any type of cell in the body. Scientists study stem cells to learn how and why they differentiate into so many different cell types. In the future, these cells could be used to regenerate tissues and organs damaged by injury or disease. Stem cell therapy is a procedure that uses stem cells to treat a disease or condition. Currently, stem cell therapy treats only blood diseases and cancers. For example, in leukemia, the patient's bone marrow produces many abnormal white blood cells that cannot perform their function of fighting infections. Over time, these abnormal cells crowd out the production of healthy white blood cells. In stem cell therapy for leukemia, called hematopoietic stem cell transplantation, a doctor takes a sample of blood or bone marrow from the patient or a donor. In some cases, the donor blood may come from a baby's umbilical cord after birth. These tissue samples contain healthy hematopoietic stem cells, or cells responsible for forming blood. Doctors then give patients chemotherapy drugs or use radiation to kill the abnormal white blood cells and their stem cells. Once the stem cells are gone, the doctor transplants healthy hematopoietic stem cells from the tissue samples back into the patient. These healthy stem cells will generate more blood cells, including normal white blood cells, which will allow the body to fight infections. ANH14132es ANH14132es