Module 2 Facts Flashcards
The breasts initially develop from the? What week of gestation?
Ectoderm – 4th wk
Develop as paired mammary ridges or milk lines
Cooper’s ligaments and fat develop from the?
Mesoderm
What week of gestation does the mammary bud become evident?
5th wk
What hormones influence the primary breast development?
Placental hormones such as prolactin, estrogen and progesterone
How many lobes of glandular tissue are developed?
15-20
Lobes - lacteriferous ducts - ampulla - nipple
True
What are the glands that surround and thicken the nipple?
Glands of Montgomery
What happens to the newborns breasts after birth?
Estrogen levels in the bloodstream begin to fall which stimulates the newborns pituitary gland and breast enlargement may occur. The enlargement is mostly the ductal system, which can be accompanied by “witch’s milk”
What is witch’s milk
a liquid similar to colostrum
What happens to the breasts after ovulation?
the CL secretes progesterone, which causes proliferation of the epithelial cells within the TDLU w enlargement of the lobules, fluid retention and increased blood flow. This causes fullness and tenderness
When do the acini become fully formed and functional?
when pregnancy and lactation occur
What hormones help the breasts reach functional maturity?
Progesterone, estrogen and prolactin
What hormone decreases and then lactation can begin?
Progesterone
What hormone causes lactation and what causes it?
Prolactin, when sucking or crying begins. The myoepithelial cells contract
At age 40, the mammary glands begin to atrophy. Following menopause, the glands further involute and are replaced by
CT and fat
What’s responsible for duct development and division?
Estrogen
What’s responsible for alveolar (acini) and lobular development?
Progesterone
Colostrum
contains no fat and little water, but high in antibodies.
Milk is only produced when prolactin is
high
Milk is only produced when estrogen and progesterone are
low
Where is milk stored before it is drained?
Ampulla (lactiferous sinus)
What are the other hormonal functions of oxytocin?
stimulates the cervix and vagina, enhancing uterine contraction
What type of gland are the breasts considered?
apocrine
What is the function of the breast?
secrete milk during lactation
What are the parenchymal elements of the breast
lobules, lobes, ducts or acini
What are the stromal elements of the breast
skin, fat, CT
What’s the purpose of the areola?
To lubricate the nipple
The entire breast is enveloped in?
superficial pectoral fascia
Subcutaneous layer:
skin superficially or ct posteriorly
primarily composed of fat lobules separated by CL
Skin should be _____ or less
2mm
The fat lobules within the subcutaneous layer are ___________ in size than those that are retromammary layer
larger
The retromammary layer is primarily composed of
fat
The mammary layer is contained within the
superficial and deep layers of the superficial pectoral fascia
Is it normal to see fat immediately beneath the nipple or areola?
No
Why is the axillary tail of clinical significance?
highest incidence of breast cancer within the lymphatic drainage of the ax tail
What’s the principle source of arterial blood?
internal mammary artery
The breast receives its arterial blood from the thoracic branches of the
axillary artery and lateral thoracic arteries
What are some landmarks for located the internal mammary (parasternal) chain of LN’s?
IMA and IMV
What supplies the medial aspect of the breast with arterial blood?
Perforating arteries of the IMA
What supplies the lateral and deep portions of the breast?
Lateral thoracic and intercostal arteries
What is the venous drainage anastomotic circle that is around the nipple?
circulus venosus
Nerves of the breast
lateral and anterior cutaneous branches of the intercostal nerves
Superior and/or superolateral portions of the breast may be from the supraclavicular nerve
Lymphatic drainage converges at the nipple at the ?
plexus of Sappey
What is the primary route of lymphatic drainage?
From the posterior LN’s to the axillary LN’s (75%)
Level 1 to 2/3, through to the axilla
What is the secondary route of lymphatic drainage?
Smaller nodes located medially in the internal mammary chain (20-25%)
What is the tertiary route of lymphatic drainage?
Subcutaneous nodes (5%)
What are the lymph node groups? (8)
external mammary scapular axillary central subclavicular interpectoral (Rotter) internal mammary supraclavicular
Most nodes on mammo are divided into 3 groups depending on their relationship to the pec minor
Level 1 nodes:
Located lateral to pec minor
Level 2 nodes:
posterior or deep to pec minor
Level 3 nodes:
medial to pec minor
Rotter’s nodes:
LN’s between the pec major and minor, along the thoracoacromial artery
Nipple - collecting duct - major subareolar ducts - ampulla - segmental (principle ducts) - TDLU
False
Nipple - collecting duct - ampulla - major subareolar ducts - segmental (principle ducts) - TDLU
The lumen of each duct is line w
epithelial cells
The outer portion of the duct is line w
myoepithelial cells
Myoepithelial and epithelial cells are composed of _________ that aid in the transport of milk
contractile fibres
What’s the basic functional unit of the breast
TDLU
What is the best way to evaluate the lacteriferous duct system?
Radial and anti radial
A TDLU consists of
a lobule and a extralobular terminal duct
A lobule consists of
an intralobular terminal duct and ductules
Which pathologies originate in the TDLU?
cysts, FA’s, DCIS, LCIS, invasive ductal/lobular carcinoma, papillomas, fibrocystic changes
