What Is a Simple Epithelium?
epithelium
Epithelium
- Chinese name
- Epithelium
- Foreign name
- epithelium
- Brief introduction
- Cell layer
- Surface
- Stratum corneum
- epithelium
- Cell layers covered on all free surfaces inside and outside the animal. The tissue that makes it up is called epithelial tissue, and its cells are called epithelial cells. In principle, no blood vessels are seen in the epithelium, and there is almost no acellular part (intercellular space part). With the basement membrane and connective tissue adjacent features.
- The epithelium often secretes stratum corneum (horny epithelium) on the surface. Epithelium is divided into ectodermal epithelium (eg, epidermis of the skin), endoderm (e.g., intestinal mucosal epithelium), and mesodermal epithelium (eg, peritoneal epithelium) due to different germ layers. In addition to the main functions, there are compound epithelium (also called protective epithelium), absorption epithelium, glandular epithelium (also called secretory epithelium), sensory epithelium, and reproductive epithelium (also called embryonic epithelium). In addition, it is divided into single-layer epithelium and multi-layer epithelium according to whether the number of layers of cells constituting the epithelium is one or more layers. According to the morphology of the outermost cells seen from the side, it is divided into flat epithelium, cubic epithelium, and columnar epithelium. In addition, all cells are adjacent to the basement membrane, but because the position of the nucleus is high or low, the stratified flat epithelium and the stratified epithelium that are similar to the stratified epithelium are classified into pseudostratified ciliated epithelium and the contractile bladder wall epithelium. The so-called transitional epithelium, which changes between laminar columnar epithelium. In addition, according to the attached structures, there are ciliated epitheli-um, flagel-lated epithelium, and pigment epithelium. Vertebrates, claws, hairs, feathers, or eye lenses deformed from their epidermis, are also considered histologically to be epithelium. In the epithelium, the inner cavity of organs that are not connected to the body surface, such as blood vessels and lymphatic vessels, is called endothelium.