Epithelial tissue is modified in to two types of specialized glands called exocrine and endocrine glands.

1. Exocrine glands are glands with streets.
2. Endocrine glands are glands without streets.

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

• Serous cells excrete proteins, often enzymes. Examples include gastric chief cells and Paneth cells
• Mucous cells excrete mucus. Examples include Brunner's glands, esophageal glands, and pyloric glands
• Mixed glands excrete both protein and mucus.

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.

• SWEAT GLANDS = these are small holes like sweep where dust is removed through them,similarly here water and salts are removed from land through these pores…

• The breast is an apocrine gland that produces milk to feed an infant.apocrine sweat glands are present in axilla(arm pits) and eccrine sweat glands are present all over the body mostly in palms and soles.Apocrine glands phoke ke tarah hamare ankhon ko saaf dikhte hain balki eccrine glands unse chote aur smooth rehte hain.

• LYMPH GLANDS = BONE MARROW,THYMUS(primary lymphoid organ)

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.

• endocrine glands = produce hormones
• thyroid follicles - produce thyroid hormones
• sex glands = produce sex hormones
  • ovarian follicles - Follicular cells flat epithelial cells that originate from surface epithelium covering the ovary
• Granulosa cells - surrounding follicular cells have changed from flat to cuboidal and proliferated to produce a stratified epithelium
• hepatic lobules
• islets of langerhans
• adrenal gland = produce adrenal harmones (located supra renal)

• lymphoid follicles

• exocrine glands
  • pancreatic enzymes
  • parietal cells = produce gastric acid (rich in acid and enzymes)
  • salivary glands = produce saliva (rich in enzymes and ions)
  • sweat glands = produce sweat (rich in salts and water)
  • sebaceous glands = produce sebum oil (rich in oils and fats)
  • examples include meibomian glands of eye make tear film protect the water from evaporation,deficiency causes dry eye.
  • secretions of meibomian glands are called meibum…..
  • mucous glands = produce mucus (rich in )
  • serous glands = produce serous proteins
  • lacrimal glands = produce tear (water)

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.

• ALVEOLITRADEPOINT - situated in the lungland are many Alveoli-Tradepoints.
• GLOMERULUSCHECKPOINT - situated in the kidneyland.
• VILLITRADEPOINT - Situated in the intestinefoodmill

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.

• nephron and glomerular capillaries
• seminiferous tubules
• Alveoli and capillaries
• Villi and capillaries
• Liver and capillaries
• Spleen and capillaries
• Lymph nodes and capillaries

• Concerned with the basic needs
  • nervous tissue and capillaries
  • Muscular tissue and capillaries
• Concerned with systemic circulation
  • hepatic
  • Renal
  • Skin