Glands can be classified structurally based on both the duct and the secretory portions. Ducts are said to be compound when they are branched and are simple when they are not branched. The overall shapes of the secretory portions of glands can be tubular, acinar (rounded), or tubulo-acinar (rounded with tubular end). The secretory portion can be further described as branched tubular or coiled tubular (long and not branched). Study Figures 4-20 and 4-21 in Junqueira for diagrammatic depictions of each type of gland.

Objectives for this section:

• Recognize the major differences in the morphologically different types of glands
• Understand the various types of secretion shown by secretory cells of glands
• Recognize staining differences between serous and mucous secretory cells
• Understand the exocrine glands can be classified according to four features:
  •  the secretory portion’s shape: alveolar vs. tubular
  • the duct system: simple vs. compound
  • the nature of the secretion: mucous vs. serous
  • the mode of secretion: merocrine, apocrine, or holocrine

So, where do these glands come from and what makes them up?