====== GLANDS ======

  * GLANDS 
    * based on number of cells 
      * unicellular 
      * multicellular
    * based on presence of duct 
      * exocrine 
        * number of branches of duct 
          * simple 
            * crypts of leiburkuhn
            * sweat glands 
            * fundic glands of stomach
            * mucous glands of urethra
            * meibomian glands 
          * compound 
            * Brunner's glands 
            * mammary glands
            * submandibular glands
        * shape of secretory unit 
          * tubular 
            * coiled
              * sweat glands ( coiled tubular)
            * Intestinal glands 
            * gastric glands 
          * acinar 
            * exocrine pancreas 
            * salivary glands  
          * alveolar 
        * nature of secretory product 
          * serous 
            * serous acini
              * lined by pyramidal shaped simple columnar epithelium 
              * rounded basal nucleus 
              * Rough endoplasmic reticulum 
                * basal basophilia  
              * golgi complex well developed
                * apical eosinophilia 
              * lumen 
                * smaller than mucous acini 
              * examples 
                * parotid gland , lacrimal gland , von ebner's gland in tongue
          * mucous 
            * mucous acini 
              * lined by pyramidal shaped simple columnar epithelium 
              * flat elongated basal placed nucleus 
              * empty cytoplasm on H&E staining 
                * mucus stored in form of mucinogen granules 
                  * lost during preparation of tissue specimen
              * lumen 
                * wider 
              * staining 
                * positive with periodic-acid-schiff staining 
                * dark magenta stain  
          * mixed
            * mucous acini with serous demilunes 
      * endocrine
    * based on manner of secretion 
      * merocrine
        * vesicles 
      * apocrine 
        * through apical part 
      * holocrine  
        * whole cell disintegrates and secretes 
    * signaling 
      * paracrine signaling 
      * autocrine signaling