EpitheliumEpithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial (mesothelial) tissues line the outer surfaces of many internal organs, the corresponding inner surfaces of body cavities, and the inner surfaces of blood vessels. Epithelial tissue is one of the four basic types of animaltissue, along with connective tissue, muscle tissue and nervous tissue.
Goblet cellGoblet cells are simple columnar epithelial cells that secrete gel-forming mucins, like mucin 2 in the lower gastrointestinal tract, and mucin 5AC in the respiratory tract. The goblet cells mainly use the merocrine method of secretion, secreting vesicles into a duct, but may use apocrine methods, budding off their secretions, when under stress. The term goblet refers to the cell's goblet-like shape.
Basement membraneThe basement membrane, also known as the basal lamina, is a specialized form of extracellular matrix (ECM) common to all multicellular animals. It is a very thin, flexible, and strong sheet-like type of ECM that provides a supporting base for all types of epithelial tissue, separates it from another cell layer such as endothelium, and anchors it to the underlying connective tissue (stroma).
MucusMucus (, ) is a slippery gel produced by, and covering, mucous membranes. Mucus forms a protective barrier between epithelial cells on the internal and external surfaces of the body and the outside environment. Mucus is found in the linings of the respiratory, digestive, and urogenital systems, and in the eyes and ears. Mucus helps to trap and remove inhaled particles, and prevent the entry of pathogenicfungi, bacteria and viruses at different sites.
Gastrointestinal tractThe gastrointestinal tract (also called the GI tract, digestive tract, gut and the alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The tract is one of the largest of the body's systems. The GI tract contains all the major organs of the digestive system, in humans and other animals, including the esophagus, stomach, and intestines.
StomachThe stomach is a muscular, hollow organ in the upper gastrointestinal tract of humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is gaster which is used as gastric in medical terms related to the stomach. The stomach has a dilated structure and functions as a vital organ in the digestive system.
MucinMucins () are a family of high molecular weight, heavily glycosylated proteins (glycoconjugates) produced by epithelial tissues in most animals. Mucins are distinguished between membrane-bound mucins, forming the glycocalyx, or secreted mucins, forming mucus-gels.
UterusThe uterus (from Latinuterus, pl.: uteri or uteruses) or womb () is the organ in the reproductive system of most femalemammals, including humans, that accommodates the embryonic and fetal development of one or more fertilized eggs until birth. The uterus is a hormone-responsive sex organ that contains glands in its lining that secrete uterine milk for embryonic nourishment. (The term uterus is also applied to analogous structures in some non-mammalian animals.)
Mucociliary clearanceMucociliary clearance (MCC), mucociliary transport, or the mucociliary escalator describes the self-clearing mechanism of the airways in the respiratory system. It is one of the two protective processes for the lungs in removing inhaled particles including pathogens before they can reach the delicate tissue of the lungs. The other clearance mechanism is provided by the cough reflex. Mucociliary clearance has a major role in pulmonary hygiene.
Cell nucleusOrganelle in eukaryotic cellsHeLa cells stained for nuclear DNA with the blue fluorescentHoechst dye. The central and rightmost cells are in interphase, thus their entire nuclei are labeled. On the left, a cell is going through mitosis and its DNA has condensed.The cell nucleus (from Latin nucleus or nuculeus 'kernel, seed'; pl.: nuclei) is a membrane-bound organelle found in eukaryotic cells.
SecretionSecretion is the movement of material from one point to another, such as a secreted chemical substance from a cell or gland. In contrast, excretion is the removal of certain substances or waste products from a cell or organism. The classical mechanism of cell secretion is via secretory portals at the plasma membrane called porosomes.*As an Amazon Associate I earn from qualifying purchases.