Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 25, 2025
Each tube is lined with columnar epithelial cells, and there is a minute central passage with the "neck" at N. Here and there are seen other special cells called parietal cells, P, which are supposed to produce the acid of the gastric juice. Pepsin the important constituent of the gastric juice, has the power, in the presence of an acid, of dissolving the proteid food-stuffs.
Such a simple tissue is called an epithelium or surface-limiting tissue, and the cells are known as epithelial cells. These are united by a very small amount of a cement substance which belongs to the proteid class of material. The epithelial cells, from their shape, are known as squamous, columnar, glandular, or ciliated.
The walls of the larynx contain strips and plates of cartilage; while the nostrils and the pharynx are kept open by their bony surroundings. Cilia, n. Nucleus. The air passages are kept clean by cells especially adapted to this purpose, known as the ciliated epithelial cells. They line the mucous membrane in most of the air passages, and are so placed that the cilia project into the tubes.
From the capsules, the excretion passes through the tubules into the pelvis, and on through the ureters to the bladder. But the delicate epithelial walls of the tubules through which it passes permit the inflow of urea and other waste products from the surrounding capillaries.
A more exuberant and rapidly growing form of epithelial cancer, described by Hutchinson as the crateriform ulcer, commences on the face as a small red pimple which rapidly develops into an elevated mass shaped like a bee-hive, and breaks down in the centre.
Epithelioma frequently originates in long-standing ulcers or sinuses, and in scars, and probably results from the displacement and sequestration of epithelial cells during the process of cicatrisation. The columnar epithelial cancer or columnar epithelioma originates in mucous membranes covered with columnar epithelium, and is chiefly met with in the stomach and intestine.
The cell growth in question is effected in the ovaries; the final stage of the process, the rupture of the containing cell or ovisac, and escape of the ovule, is attended by a concentration of nervous activity in the ganglionic masses sending nerves to those organs analogous to that which occurs in the solar plexus at periods of digestion; the fall of the ovule is itself analogous to the shedding of epithelial cells in the gastric follicles; the afflux of blood to the utero-ovarian veins, analogous to the periodical congestion of the gastro-splenic vascular apparatus.
The scars resulting from severe burns and those over amputation stumps are especially liable to break down from trivial causes. The treatment is to excise the weak portion of the scar and bring the edges of the gap together. These are treated by dividing the scar, correcting the deformity, and filling up the gap with epithelial grafts, or with a flap of the whole thickness of the skin.
Delicate hairs may also be found projecting from the epithelial lining of the cyst. Faulty coalescence of the cutaneous covering of the back occurs most frequently over the lower sacral vertebræ, giving rise to small congenital recesses, known as post-anal dimples and coccygeal sinuses. These recesses are lined with skin, which is furnished with hairs, sebaceous and sweat glands.
C. Single taste bud magnified. n. Nerve, the fibers of which terminate between the spindle-shaped cells a. e. Epithelial cells. *The Sensation of Taste.*—The sense organs of taste are found chiefly in the mucous membrane covering the upper surface of the tongue.
Word Of The Day
Others Looking