Specialized cell junctions.
Respiratory epithelium is a type of epithelium found lining the respiratory tract, where it serves to moisten and protect the airways. It also functions as a barrier to potential pathogens and foreign particles, preventing infection and tissue injury by action of the mucociliary escalator. Hence, it appears as though several layers of cells are present and the epithelium is called pseudostratified. The majority of cells composing the ciliated pseudostratified columnar epithelium are of three types: a) ciliated cells, b) goblet cells, and c) basal cells. 3 Principal characteristics of cells that make up epithelium. -Cells are closely apposed-they adhere to one another via specialized cell junctions-Exhibit both structural and functional polarity-Epithelium creates a selective barrier between the external environment and the underlying connective tissue.   . Pseudostratified ciliated columnar epithelium. -Some cells do not reach the surface of the epithelium so their nuclei are present in different heights of the epithelial layer-However, all the cells contact the basement membrane. -Cells are closely apposed-they adhere to one another via specialized cell junctions-Exhibit both structural and functional polarity-Epithelium creates a selective barrier between the external environment and the underlying connective tissue.   . The respiratory system consists of a conducting portion and a respiratory portion. The conducting portion provides a passageway for air and functions to condition the incoming air, by warming, moistening and cleaning it. It consists of the nasopharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles.  Epithelia Cells that line surfaces: Epithelium is the name given to the cells that line a surface. The outer surface of the body is lined by an epithelium called the epidermis. The inside of the body cavity is also lined by an epithelium, as is the outer surface of many internal organs. Cells that line surfaces. Epithelium is the name given to the cells that line a surface. The outer surface of the body is lined by an epithelium called the epidermis. The inside of the body cavity is also lined by an epithelium, as is the outer surface of many internal organs. Simple columnar epithelial cells may be specialized for secretion (such as the goblet cells that secrete a protective layer of mucus in the small intestine), for absorption or for protection from abrasion. Columnar epithelial cells line a large part of the digestive tract, oviducts and many glands.  Tissues that line the inside of the mouth, the esophagus and part of the rectum are composed of nonkeratinized stratified squamous epithelium. Other surfaces that separate body cavities from the outside environment are lined by simple squamous, columnar, or pseudostratified epithelial cells. The other three types are connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of blood vessels and organs throughout the body. There are three principal shapes of epithelial cells: squamous, columnar, and cuboidal. The histological structure of the epithelium and the underlying connective tissue of the bronchi corresponds largely to that of the trachea and the main bronchi. In addition, bronchi are surrounded by a layer of smooth muscle, which is located between the cartilage and epithelium. In addition to the staple of basal cells, ciliated cells and goblet cells, the respiratory epithelium also contains brush cells, endocrine cells (or small granule cells, function not clear) , surfactant-producing cells (or Clara cells) , and serous cells. Simple squamous epithelium. This type is composed of a single layer of flattened, scale-or plate-like cells. It is quite common in the body. The large body cavities and heart, blood vessels and lymph vessels are typically lined by a simple squamous epithelium. Epithelia are avascular, but all epithelia grow on an underlying layer of vascular connective tissue. The connective tissue and the epithelium are separated by a basement membrane. Epithelium covers all free surfaces of the body. Epithelium also lines the large internal body cavities, where it is termed mesothelium.
https://en.wikipedia.org/wiki/Respiratory_epithelium https://quizlet.com/25466734/epithelium-flash-cards/ https://quizlet.com/25466734/epithelium-flash-cards/ http://courseweb.edteched.uottawa.ca/medicine-histology/English/Respiratory/Default.htm http://www.courseweb.uottawa.ca/medicine-histology/English/SS_BasicTissues/Epithelia.htm http://www.uwlax.edu/biology/zoo-lab/lab-2--microscopy-and-the-study-of-tissues// https://en.wikipedia.org/wiki/Epithelium http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Respiratory/respir.htm http://www.lab.anhb.uwa.edu.au/mb140/CorePages/Epithelia/epithel.htm
what cells are found within the epithelium lines of trachea quizlet