histology of the breast Flashcards
what type of gland is the breast?
subcutaenous gland
secretory tissue of the breast is made up of how many lobes?
15-25 lobes
- each consisting of a compound tubulo-acinar gland which drains via a series of ducts leading to the nipple
what is found adjacent to secretory lobules?
- dense fibrous tissue - which in turn is surrounded by adipose tissue
what are suspensory ligaments?
- extend from dermis of skin to deep fascia overlying muscle of ant chest wall
- function: to support to breast tissue
what is the basic functional secretory unit of the breast called?
- terminal duct lobular unit
- in non-lactating breast, terminal ductules -> an intralobular collecting duct -> lactiferous duct for that lobe -> nipple (lactiferous sinus)
what is contained within structure of the lobule?
- extralobular and intralobular ducts
- rudimentary secretory acini
- dense fibrocollagenous CT surrounding lobule
- looser connective tissue surrounding acini (allows rapid expansion in pregnancy)
- adipose tissue between lobules
within the lobule the secretory epithelial cells that line the acini are what kind of cells?
- cuboidal
- columnar
secretory cells of acinus are surrounded by what kind of cells?
- myoepithelial cells (MEp)
function: contractile epithelial cells and are surrounded by basal lamina
larger ducts e.g. lactiferous duct are lined by what kind of epithelium?
- stratified squamous to stratified cuboidal cells
nipple is covered by a thin layer of pigmented …. ….. …. epithelium?
- keratinized, stratified, squamous epithelium
what structure can be found within the nipple?
- lactiferous ducts
: serve one lobe of the breast
what change occurs to epithelial cells during the luteal phase?
- cells inc in height
what changes occur to ducts during the luteal phase?
- lumina of the ducts enlarges
- small amounts of secretions appear in the ducts
1st trimester of pregnancy what changes occur to ducts, glands?
- elongation and branching of smaller ducts
- proliferation of epithelial cells of glands
- proliferation of myoepithelial cells
2nd trimester what changes occur to glandular tissue?
continues to develop w differentiation of secretory alveoli
plasma cells and lymphocytes infiltrate nearby connective tissue
3rd trimester what occurs to glandular tissue of breast?
- seretory alveoli continue to mature
- development of extensive rER
during pregnancy there is a reduction in the amount of connective tissue and adipose tissue true or false?
true
what 2 hormones stimulate proliferation of secretory tissue during pregnancy?
- oestrogen and progesterone
milk is made up of predominantly what substance?
- 88% water
what antibodies are found in human milk?
- IgA antibodies
what is apocrine secretion?
- when lipid droplets are secreted surrounded by membrane and carrying small amount of cytoplasm with it
what is merocrine secretion?
- exocytosis
- process by which protein packaged in golgia apparatus is secreted via vesicles and merges with apical membrane to release only their contents into the duct system
proteins in milk are made where?
rER
following menopause what happens to secretory cells of the TDLU?
- they degenerate leaving only ducts
- fewer fibroblasts
- reduced collagen and elastic fibres
what is the blood supply to the breast tissue?
- lateral mammary branches from lateral thoracic a
- medial mammary branches from internal thoracic a
what veeins are involved in the venous drainage of breast?
- medial and lateral mammary veins
what vessels are involved in the venous drainage of the breast?
- medial and lateral mammary veins
where does the majority of lymph drain from the breast to?
- axillary lymph nodes 75%
-> remainder to parasternal nodes
-> some may also drain to abdominal nodes
