Findings

At high magnification, a portion of a lobule is shown adjacent to an excretory duct. Note the numerous secretory alveoli of various sizes and the stratified epithelium of the excretory duct. Secretory product is seen in the lumina of both alveoli and ducts.

Comment

In the lactating mammary gland, release of oxytocin by the posterior pituitary gland stimulates myoepithelial cells to contract, which ejects secretory products from the alveoli and ducts. Myoepithelial cells, though not clearly seen here, lie between the epithelium and basement membrane.

Preparation

Paraffin section, hematoxylin and eosin

View

High-power light microscopy

Specimen

Mammary gland

Image Credit

V. Eroschenko, Ph.D.
Department of Biological Sciences
WAMI Medical Program
University of Idaho