two types of glands:
endocrine - synthesize and release hormonoes - epithelial tissue
endocrine (epithelial tissue)- secretions through excretory ducts, contents modified in duct
classification of exocrine glands
based on the type of secretion, mode of secretion, and cell numbers
type of secretion (exocrine)
mucous, serous, mixed, sebaceous
mode of secretion (exocrine)
merocrine, apocrine, holocrine
mucous glands
-Secrete mucinogens, large glycosylated proteins (PAS positive), that when hydrated form a thick (viscous), protective fluid called mucin. Mucin is a component of mucus.
-Examples, include goblet cells and mucous cells of the stomach
-Mucus can form plugs – example, respiratory passageways of asthmatics
-nucleus on/near basement membrance ands ecretory product on top (clear)
MOSTLY CLEAR STAINING
serous glands
-Secretions are watery in consistency and enriched with enzymes
-Examples are parotid gland and exocrine pancreas, salivary glands
ACIDOPHILIC- DARKER
mixed glands
- Examples are submandibular and sublingual gland
sebaceous glands
merocrine
apocrine
holocrine
- Cells of sebaceous glands
acne
Hair shaft penetrates the hair follicle, eliciting inflammatory and fibrotic responses. Inflammatory cells, giant cell, and fibrosis are observed.
With hormones sebaceous glads get activated
most common type of secretion
merocrine
cell numbers (exocrine)
unicellular
multicellular
unicellular
- Example is the goblet cell found in the GI tube and respiratory airways
multicellular
classification of endocrine glands
based on shape of the secretory unit and nature of their duct system
adenomas
bengin cancers
adenocarcinomas
malignant cancers
shape of secretory units
acinus (alveolus) - grape looking
tubular
can contain both
duct system of secretory units
intralobar ducts
-found within the lobule of the exocrine gland - intercalated disks, striated ducts (not in all glands)
interlobular ducts
found in the connective septa that separate lobules
interlobar
receive the interlobular ducts and drain the lobes of the gland