-plasm Also -plasia, -plasmic, and -plast.
Growth or development; living substance; tissue.
[Greek plasis or plasma, formation, from plassein, to shape or mould.]
Words in -plasm refer to kinds of cell tissue. Examples are cytoplasm, the material within a living cell (excluding the nucleus, whose substance is the nucleoplasm); neoplasm, a new and abnormal growth of tissue in some part of the body, especially as a characteristic of cancer; protoplasm, the colourless material comprising the living part of a cell, including the cytoplasm, nucleus, and other organelles; ectoplasm, either the more viscous, clear outer layer of the cytoplasm in amoeboid cells, or a viscous substance that is supposed to exude from the body of a medium during a spiritualistic trance. Associated adjectives are formed in -plasmic: cytoplasmic, ectoplasmic, protoplasmic.
The ending -plasia forms names for types of cell growth, mostly abnormal. Examples include dysplasia (Greek dus-, bad or difficult), abnormal growth or development of skin, bone, or other tissues; hyperplasia (Greek huper, over, beyond), the increased production and growth of normal cells in a tissue or organ; neoplasia (Greek neos, new), the presence or formation of new, abnormal growth of tissue; aplasia (Greek a-, not or without), the failure of an organ or tissue to develop or to function normally.
The -plast ending refers to components of cells, mostly in plants, such as plastids (from the same Greek root), members of a class of small organelles in the cytoplasm of plant cells, containing pigment or food. Examples include chloroplast (Greek khlōros, green), a plastid in green plant cells which contains chlorophyll and in which photosynthesis takes place; protoplast (Greek prōtos, first), the protoplasm of a living plant or bacterial cell whose cell wall has been removed; kinetoplast, a mass of mitochondrial DNA lying close to the nucleus in some flagellate protozoa; tonoplast (Greek tonos, tension, tone), a membrane which bounds the chief vacuole of a plant cell.