This is also heterogeneous, i.e. a composite of carbon-poor iron and cementite. Going to very fast cooling (quenching) will result in a single-phase (not composite) material called martensite. Here the carbon doesn't have time to exit the iron, and this martensite phase is very hard, but also normally too brittle.
Epithelial tissue - to cover the inner and outer surfaces of the stomach The stomach is one of the organs that form the digestive system. The stomach contains various tissues, and each tissue is made of a particular type of cell. In order of increasing size and complexity: cells â tissues â organ (the stomach) â organ system (the digestive system)
The stomach wall has 5 layers: 1  The innermost layer is the mucosa. This is where stomach acid and digestive enzymes are made. 2  Next is a supporting layer called the submucosa. 3  Outside of this is the muscularis propria, a thick layer of muscle that moves and mixes the stomach contents.