The epithelium with secretory function is called glandular epithelium; Mainly composed of glandular epithelium organ It is called gland. According to whether or not catheter ： Endocrine glands have no ducts, and secretions are transported through blood and lymph.
Exocrine gland The catheter leads to the organ cavity or body surface, and the secretion is discharged through the catheter. classification
According to the number of gland cells: single cell gland and Multicellular gland According to whether the duct has branches: single gland and compound gland
According to the shape of the secretory part: tubular glands, vesicular glands and tubular vesicular glands
According to the nature of secretion: serous gonad, mucinous gonad and mixed gland
According to the discharge mode of secretions: secretory gland, apocrine secretion, and local secretion
notes
① Pancrine gland: the secretion fills the whole cell, the cell finally dies and disintegrates, and the whole cell is discharged together with the secretion, such as sebaceous gland.
② Apocrine secretion: the secretion at the top of the cell gradually protrudes to the surface into bubbles, and finally separates from the cell with the outer cell membrane and falls off. The membrane at the top of the cell was also immediately closed, and the cytoplasm was not lost. breast And some sweat glands belong to this type. ③ Local plasma secretion: the top secretory granules expel secretions by exocytosis or directly through the top cell membrane, such as salivary glands pancreas Etc. 
