Chapter 28: The breasts and mammary glands Flashcards
What is the breast?
a mound of tissue overlying the pectoralis major muscle. It enlarges at puberty and remains so for life.
mammary gland
develops within the breast during pregnancy, remains active in the lactating breast, and atrophies when a woman ceases to nurse
What are the two principles regions of the breast?
the conical to pendulous body, with the nipple at its apex
and the extension toward the armpit called the axillary tail.
What happens to the areola during pregnancy?
the levels of melanin deposition go up making them more visible to a nursing infant
What are sensory nerve fibers in the areolar important for?
they trigger a milk ejection reflex when an infant nurses.
What does the inid of a nonlactating breas consist of?
mostly adipose and collagenous tissue
What are suspensory ligaments?
they attach the breast to the dermis of the overlying skin and to the fascia of the underlying muscle
What happens to the breast when the mammary gland develops during pregnancy?
it exhibits 15 to 20 lobes arranged radially around the nipple, separated from each other by stroma
What ducts drain the lobes of the mammary gland during pregnancy?
the lactiferous duct which dilates to form a lactiferous sinus opening onto the nipple.
What are acini?
they are branches of the lactiferous ducts with fine branches. The acini are organized into grape like clusters within each lobe of the breast
what kind of cells are found around acinus?
contractile myoepithelial cells.
