BREAST Flashcards
how many lobes make up the secretory tissue of the breast
15-25
what does each lobe consist of
a compound tubular-acinar gland which drains via a series of ducts leading to the nipple
what kind of tissue is adjacent to the secretory lobules
dense fibrous tissue which is surrounded by adipose tissue
what ribs does the bed of the breast expand from
ribs 2 - 6
what are the lateral borders of the breast bed
lateral border of the sternum and mid axillary line
most lymph of the breast drains where
ipsilateral axillary lymph nodes
where do the axillary nodes drain
supraclavicular nodes –> thoracic duct
where else can lymph from the breast drain
parasternal nodes and abdominal nodes
nodes of contralateral breast
position of the levels of lymph nodes is described in relation to what muscle
pec minor
what are level 1 nodes
inferior and lateral to pec minor
what are level 2 nodes
deep to pec minor
what are level 3 nodes
superior and medial to pec minor
what structures support the breast
suspensory ligaments (coopers ligaments)
where do the suspensory ligaments attach
dermis of the skin to deep fascia overlying the muscle of anterior chest wall (pec major and serratus ant)
what is the functional secretory unit of the breast
terminal duct lobular unit
what do terminal ductules (acini) lead into
intralobular collecting duct
what does the intralobular collecting duct lead into
lactiferous duct for that lobe
where does the lactiferous duct lead
nipple
before the lactiferous duct reaches the nipple what does it pass through
lactiferous sinus
what is the lactiferous sinus
expanded duct region near the nipple where the lactiferous ducts drain
- storage of milk
how does the connective tissue differ from around the lobule to around the acini within the lobule
around the lobule - dense fibrocollagenous
around the acini - looser connective tissue
why is the connective tissue around the acini looser than around the lobule
to allow rapid expansion during pregnancy
what kind of cells line the acini
secretory epithelium (vary from cuboidal to columnar)
what cells surround the secretory cells of the acini
myoepithelial cells
what are myoepithelial cells
contractile epithelial cells
what surrounds the myoepithelial cells
basal lamina
what cells line the lactiferous duct towards the nipple
thin stratified squamous epithelium
what cells line the deeper parts of the lactiferous duct
stratified cuboidal epithelium
how thick are the cells lining the deepest parts of the lactiferous duct
one cell thick
what glands end directly on the skin surface of the nipple (only place in the body this happens)
sebaceous glands
what cells line the nipple surface
thin, highly pigmented keratinised stratified squamous epithelium
what makes up the core of the nipple
dense irregular fibrocollagenous connective tissue mixed with bundles of smooth muscle
how many lobes does one lactiferous duct serve
1 each
mammary tissue only changes in pregnancy
true/false
false
changes during the menstrual cycle
during which phase of the menstrual cycle does the mammary tissue change
luteal phase
how do the breasts change in the luteal phase
- epithelial cells increase in height
- lumina of the ducts enlarges
- small amounts of secretions appear in the ducts
what occurs in the first trimester of pregnancy re the breasts (2)
- elongation and branching of the smaller ducts
- proliferation of the epithelial cells of the glands and the myoepithelial cells
what cell types proliferate in the first trimester of pregnancy
epithelial cells
myoepithelial cells
in the first trimester of pregnancy there is ____ and _____ of the smaller ducts
elongation and branching
what cells infiltrate the nearby connective tissue in the second trimester of pregnancy
lymphocytes and plasma cells
what do plasma cells produce in the breast
IgA
what occur in the second trimester of pregnancy
- glandular tissue continues to develop with differentiation of secretory alveoli
- plasma cells and lymphocytes infiltrate the nearby connective tissue
what occurs in the third trimester of pregnancy
secretory alveoli continue to mature with development of extensive rER
what happens to the amount of connective tissue and adipose tissue in the breasts during pregnancy
reduction
what hormones stimulate proliferation of secretory tissue and degeneration of fibro-fatty tissue in pregnancy
oestrogen and progesterone
what is the main component of breast milk
water (88%)
what % protein is in the breast milk
1.5%
what mainly makes up the protein in the breast milk
lactalbumin
casein
what % of the breast milk is CHO
7%
what is the main form of CHO in the breast milk
lactose
what % of the breast milk is lipid
3.5%
what else is in the breast milk
ions, vitamins, IgA
how is lipid secreted into the milk
- description and name of type
apocrine secretion
- lipid droplets are secreted surround by membrane and carrying a small amount of cytoplasm
how are proteins secreted into milk
- description and name
merocrine secretion (exocytosis)
- made in rER
- packaged in golgi
- secreted via vesicles that merge with apical membrane to release only their components into duct (no cytoplasm)
what occurs to the secretory cells of the TDLU’s following menopause
degenerate leaving only ducts
following menopause there is
- more/less fibroblasts
- increased/decreased collagen and elastic fibres
less fibroblasts
decreased collagen and elastic fibres
orange peel appearance of breast skin can indicate what
breast cancer
what is the retromammary space
space between breast tissue and fascia
what hormone causes production of breast milk
prolactin
what hormone causes the ejection of breast milk
oxytocin
oxytocin causes the contraction of what
myoepithelium
young adults have a higher proportion of adipose/glandular tissue
higher proportion of glandular tissue compared to adipose - denser
elderly breasts have more _____ tissue making them ____ dense
adipose
less dense
what are milk lines
developmental lines on which mammary glands and nipples develop
what is the definition of metaplasia
the change from one fully differentiated cell type to another fully differentiated cell type
what hormone stimulates the lactiferous ducts to grow at puberty
oestrogen
after menarche what hormone induces further growth and development of the rudimentary lobules at the end of the bulb
progesterone
