Glossary of Common Stem Cell Terms
The following is a glossary of common stem cell terms provided for your convenience.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- astrocyte
- A type of supporting (glial) cell found in the nervous system. | A star-shaped cell that supports the tissue of the central nervous system.
- blastocyst
- A very early embryo consisting of approximately 150 cells produced by cell division following fertilization. The blastocyst is a spherical cell mass that contains a fluid-filled cavity (the blastocoel), a cluster of cells called the inner cell mass (from which embryonic stem cells are derived) and an outer layer of cells called the trophoblast (that forms the placenta).
- cell culture
- The Growth of cells in vitro in an artificial medium for research or medical treatment.
- cell division
- The method by which a single cell divides to create two cells. There are two main types of cell division depending on what happens to the chromosomes: mitosis and meiosis.
- cell line
- Cells that can be maintained and grown in culture and display an immortal or indefinite life span.
- cell type
- A specific subset of cells within the body, defined by their appearance, location and function.
- chromosome
- A structure consisting of DNA and regulatory proteins found in the nucleus of the cell. The DNA in the nucleus is usually divided up among several chromosomes.The number of chromosomes in the nucleus varies depending on the species of the organism. Humans have 46 chromosomes.
- differentiation
- The process of development by which an unspecialized embryonic cell acquires the features of a specialized cell such as a heart, liver, or muscle cell.
- DNA (Deoxyribonucleic Acid)
- A chemical found primarily in the nucleus of cells. DNA carries the instructions or blueprint for making all the structures and materials the body needs to function. DNA consists of both genes and non-gene DNA in between the genes.
- ectoderm
- The outermost germ layer of cells (derived from the inner cell mass of the blastocyst) that gives rise in later development to the nervous system, sensory organs, skin, and related structures.
- embryonic stem cells
- Also called ES cells, embryonic stem cells are derived from the inner cell mass of an early stage embryo known as a blastocyst. ES are capable of dividing without differentiating for a prolonged period in culture, and are known to develop into cells and tissues of the three primary germ layers.
- endoderm
- The innermost germ layer of cells (derived from the inner cell mass of the blastocyst) that gives rise in later development to tissues such as the lungs, the intestine, the liver and the pancreas.
- fertilization
- The joining of the male gamete (sperm) and the female gamete (egg).
- fetus
- The stage in human development from approximately eight weeks after fertilization to developed organism that ends at birth.
- gene
- A functional unit of heredity that is a segment of DNA found on chromosomes in the nucleus of a cell. Genes direct the formation of an enzyme or other protein.
- germ layers
- The three germ layers are the endoderm, mesoderm and ectoderm and are the three precursory tissue layers of the early, primitive embryo (which form at approximately two weeks in the human) that give rise to all tissues of the body.
- hematopoietic stem cells (HSCs)
- Stem cells that gives rise to red and white blood cells and platelets.
- in vitro
- Latin for "in glass"; refers to the technique of performing a given procedure in a controlled environment outside of a living organism.
- in vitro fertilization
- A technique that unites the egg and sperm in a laboratory instead of the female organism. The resulting fertilized egg, called a zygote, will start dividing and after a several divisions, forms the embryo that can be implanted into the womb and give rise to pregnancy.
- mesoderm
- The middle of three germ layers that gives rise later in development to such tissues as bone, muscle, connective tissue, kidneys, and related structures.
- meiosis
- The type of cell division a diploid germ cell undergoes to produce gametes (sperm or eggs) that will carry half the normal chromosome number. This is to ensure that when fertilization occurs, the fertilized egg will carry the normal number of chromosomes rather than causing aneuploidy (an abnormal number of chromosomes).
- mesenchymal stem cells
- Also known as bone marrow stromal cells, mesenchymal stem cells are rare cells, mainly found in the bone marrow, that can give rise to a large number of tissue types such as bone, cartilage (the lining of joints), fat tissue, and connective tissue (tissue that is in between organs and structures in the body).
- mitosis
- The type of cell division that allows a population of cells to increase its numbers or to maintain its numbers. The number of chromosomes remains the same in this type of cell division.
- morphology
- The study of the shape and visual appearance of cells, tissues and organs.
- multipotent
- Stem cells whose progeny are of multiple differentiated cell types, but all within a particular tissue, organ, or physiological system. For example, hematopoietic stem cells are single multipotent cells that can produce all cell types that are normal components of the blood. See also pluripotent and totipotent.
- neural stem cell
- A type of stem cell that resides in the brain, which can make new nerve cells (called neurons) and other cells that support nerve cells (called glia). In the adult, neural stem cells can be found in very specific and very small areas of the brain where replacement of nerve cells is seen.
- neurons
- Nerve cells, the principal functional units of the nervous system. A neuron consists of a cell body and its processes-an axon and one or more dendrites. Neurons transmit information to other neurons or cells by releasing neurotransmitters at synapses.
- nucleus
- A part of the cell, situated more or less in the middle of the cell, that is surrounded by a specialized membrane and contains the DNA of the cell.
- pluripotent
- A stem cell that has the potential to differentiate into any of the three germ layers: ectoderm, mesoderm and endoderm. Pluripotent stem cells can give rise to any fetal or adult cell type. However, alone they cannot develop into a fetal or adult animal because they lack the potential to contribute to extra-embryonic tissue, such as the placenta.
- regenerative medicine
- The field of medicine devoted to treatments in which stem cells are induced to differentiate into the specific cell type required to repair damaged or destroyed cell populations or tissues.
- stem cells
- Cells that have both the capacity to self-renew (make more stem cells by cell division) as well as to differentiate into mature, specialized cells.
- undifferentiated
- A cell that has not yet developed into a specialized cell type.
- zygote
- The cell that results from the union of sperm and egg during fertilization. After the zygote forms, cell division begins.
