• Glands are epithelial in origin
• Development of glands can occur fron any of the 3 germ layers i.e Ectoderm, Mesoderm or Endoderm.
• Glands can be divided into different types based on number of cells, secretion and site of release.

TYPES OF GLANDS (On the basis of secretion)

APOCRINE GLANDS

• The secretion of first accumulates in the apical part of the cells and is later pinch off in the form of a vesicle.
• The size of the cell decreases due to secretion
• The cell regrows and again accumulates the secretions
• Examples: Sweat glands of armpits and thighpits, Mammary glands

MEROCRINE GLANDS

• The secretions diffuses out of the cell
• The cells are not damaged during secretion
• Merocrine glands are also called Eccrine glands
• Examples: Salivary glands and sweat glands

HOLOCRINE GLANDS

• The entire cell disintegrates and releases the secretion out
• The secretions released are oily
• Example: Sebaceous glands