Epithelial tissue is modified in to two types of specialized glands called exocrine and endocrine glands.
1.1 Exocrine glands are glands that produce and secrete substances onto an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, and mucous
By product excreted
Examples include the salivary glands: although the parotid gland 20%is predominantly serous, the sublingual gland 5% mainly mucous gland, and the submandibular gland 70%is a mixed, mainly serous gland.
LYMPH NODE = Bean shaped glands(secondary lymphoid organs) and are also included spleen,peyer's patches,adenoids,tonsils that are associated with (MALT).they care called as POLICE STATIONS OR MILITARY ACADEMY.
Glands glands have a structure called follicle . A follicle is a small spherical or vase-like group of cells enclosing a cavity in which some other structure grows or other material is contained. THIS IS CALLED THE VASE OR BIG POT WHICH IS PROTECTED BY A GROUP OF PERSONS OR LIKE A COOKWARE IN WHICH THE NECESSARY PRECURSORS ARE SYNTHESISED AND STORED.
Follicles are epithelial cells hence they are present outside in cortex but not in medulla or middle….
CORTEX IS THE OUTER GROUP MEDULLA IS THE INNER POT
ovarian cortex - containing ovarian follicles lymphoid cortex - containing lymphoid follicles adrenal cortex - containing three different zones called rather than follicles , glomerulosa(ball - similar to external follicles) , fasciculata(bundle) and reticularis (inner network). the ball produces mineralocorticoids-aldosterone,the radially bundle - cortisol and irregular cluster - androgens
ovarian medulla - follicles not found in medulla lymphoid medulla - adrenal medulla - site for the conversion of amino acid tyrosine to catecholamines ,adrenaline ,nor adrenaline and dopamine . modified post ganglionic neurons of sympathetic nervous system.
There are three types of glands: cardiac glands (in the proximal part of the stomach), fundic (oxyntic) glands(the dominating type of gland), and pyloric glands. The cardiac glands mainly contain mucus-producing cells called foveolar cells. The bottom part of the oxyntic glands is dominated by zymogenic (chief) cells that produce pepsinogen (an inactive precursor of thepepsin enzyme). Parietal cells, which secretehydrochloric acid (HCl) are scattered in the glands, with most of them in the middle part. The upper part of the glands consist of mucous neck cells; in this part the dividing cells are seen. The pyloric glands contain mucus-secreting cells. Several types of endocrine cells are found in throughout the gastric mucosa. The pyloric glands contain gastrin-producing cells (G cells); this hormone stimulates acid production from the parietal cells.Enterochromaffin-like cells (ECLs), found in the oxyntic glands release histamine, which also is a powerful stimulant of the acid secretion. The A cells produceglucagon, which mobilizes the hepatic glycogen, and the enterochromaffin cells produce serotonin, which stimulates the contraction of the smooth muscles.
The surface of the mucous membrane is covered by a single layer of columnar epithelium. This epithelium commences very abruptly at the cardiac orifice, where there is a sudden transition from the stratified epithelium of the esophagus. The epithelial lining of the gland ducts is of the same character and is continuous with the general epithelial lining of the stomach. An important iodine concentration by sodium-iodide symporter (NIS) is present in mucinous cells of surface epithelium and gastric pits of the fundus and pyloric part of the stomach. glands help in thermoregulation by forming a dry and wet combination (wet is due to sweat it is emulsified to become like a dry layer so that it sticks and is not lost as water drops which delays dehydration)…
Every land has buildings.Some buildings are called houses and some are called with other names and in the houses there are rooms. so the microcirculation refers to the road to the stomachland cell(rooms with persons) EACH person receives food and water through transport system,in a similar way each cell receives food from blood circulation.exchangepoint are present in all types of land.This point serves as the point where the roads from heartland exchange their materials with the land rooms. capillaryexchangepoint = types of capillaries. each cell and its envrionment can be referred to as a factory.
Whether it is a checkpoint or a food-mill every land requires person in order to operate, so whether it is alveoli or villus or glomerulus, it requires cells to function.