Breast Anatomy/Histology Flashcards
breast extends vertically from ___ rib to ___ rib
2nd to 6th rib
level of nipple in female
4th intercostal space
nipple is pierced by 15-20 ________ ducts
lactiferous
what type of muscle does the nipple contain
smooth muscle
outer margin of the areola contains a number of modified _______ glands
sebaceous
what are enlarged sebaceous glands during pregnancy called
tubercles of montgomery
what are the 3 components of the mammary gland
- glandular tissue
- fibrous tissue
- interlobular fatty tissue
what are the suspensory ligaments of cooper
connective tissue in the breast that help maintain structural integrity.
where are the suspensory ligaments of cooper more prominent in the breast
upper part of the breast
how many pyramidal lobes make up the glandular tissue
15-20
each lobe is drained by separate __________ ________
lactiferous duct
each duct dilates to form lactiferous ____
sinus
the area of the breast drained by one terminal duct is known as a ________
lobule
what is the basic functional secretory unit of the breast
the Terminal Duct Lobular Unit (TDLU)
dense connective tissue
collagen fibres compact
loose connective tissue
collagen fibres quite separated, with spaces
where are dense and loose connective tissue found
dense - surrounding the lobule
loose - surrounding the acini within the lobule
within the lobule the secretory epithelial cells line the _____
acini
the secretory cells of the acini are surrounded by ____________ cells
myoepithelial
what are myoepithelial cells
contractile epithelial cells
stellate-shaped and also known as basket cells.
in the nipple, how many lobes of the breast does each lactiferous duct serve
one
changes in the breast in menstrual cycle
During the luteal phase:
- the epithelial cells increase in height
- the lumina of the ducts becomes enlarged
- small amounts of secretions appear in the ducts.
changes in the breast in pregnancy - first trimester
elongation and branching of the smaller ducts, combined with proliferation of the epithelial cells of the glands and the myoepithelial cells.
changes in the breast in pregnancy - second trimester
glandular tissue continues to develop with differentiation of secretory alveoli. Also, plasma cells and lymphocytes infiltrate the nearby connective tissue.
changes in the breast in pregnancy - third trimester
secretory alveoli continue to mature, with development of extensive rough endoplasmic reticulum
changes in the breast in pregnancy
increase in acini, decrease in adipose and connective tissue
what percentage of human milk is water
88%
Human milk: Lipid droplets are secreted surrounded by membrane and carrying a small amount of cytoplasm with it. This form of secretion is known as _________ secretion.
apocrine
Human milk: The proteins in milk are made in the rER, packaged in the Golgi apparatus and secreted via vesicles (v) which merge with the apical membrane to release only their contents into the duct system. This is ________ secretion (also termed exocytosis).
merocrine
changes in breast after menopause
the secretory cells of the TDLU’s degenerate leaving only ducts.
In the connective tissue, there are fewer fibroblasts and reduced collagen and elastic fibres.
blood supply to breast
lateral mammary branches from lateral thoracic artery
medial mammary branches from Internal Thoracic artery
venous drainage of breast
Venous drainage by Medial and Lateral Mammary veins
innervation of the breast
Anterior and lateral branches of the fourth to sixth intercostal nerves, which carry sensory and sympathetic efferent fibres.
nipple innervation
anterior branch of the lateral cutaneous branch of T4
