How many lobes is each breast subdivided into?
12-20
What is one function, other than the let-down reflex, caused by oxytocin release?
- Increase uterine muscle contractions )(involution)
- Stimulates digestive and metabolic processes
- anti-stress effects including decrease BP and cortisol levels
What encodes for testis determining factor on the Y chromosome?
Sry
What cell type is not present in invasive carcinoma?
Myoepithelial
Name two anatomical differences in a lactating breast compared to a non-lactating breast
Peristaltic motion of the tongue
What is the hormone that promotes regression of the paramesonephric duct?
AMH
Name three symptoms of breast disease
- nipple discharge
- breast pain
- breast lump
- axillary mass/lymphadenopathy
- asymptomatic/screen-detected abnormality
Name three sets of lymph nodes that the breast drains to
Name one change that occurs in the breast during each stage of the menstrual cycle (proliferative, secretory and menstrual)
Proliferative phase
- rising oestrogen levels stimulate parenchymal proliferation
Secretory phase
- locular oedema
- increased mammary blood flow
- thickening of epithelial basement membrane
Menstrual phase
- degeneration of glandular tissue
- loss of oedema
- reduction in blood flow
What is a corrected age and at what point does corrected age stop being used?
Age corrected for gestation
Over 2 years of age don’t tend to correct anymore as kids tend to have caught up by then
Name one chronic (non-lactational) form of mastitis and one histological feature associated with it
Granulomatous - epithelioid macrophages forming granulomata surrounding ducts and lobules
Where is the lactiferous sinus located and what is its purpose?
Dilation of the lactiferous duct just below nipple. Act as a reservoir for milk during breast feeding
There are three stages in lactogenesis, what are they called, when do they occur and what happens during each stage?
Lactogenesis I - beginning of colostrum production in mid-pregnancy
Lactogenesis II - initiated following delivery of placenta, withdrawal of progesterone and oestrogen (and infant suckling) causes depression of PIF and stimulation of prolactin releasing factors
Lactogenesis III (galactopoiesis) - maintenance of milk production
When do primordial germ cells start to differentiate and where do they reside prior to their migration to the gonadal ridge?
During gastrulation
Yolk sac
What are the two most common subtypes of breast adenocarcinoma and what is the histological pattern of the invasive form of each subtype?
Ductal adenocarcinoma - clump/nest/cord pattern
Lobular adenocarcinoma - slender linear strands (Indian file pattern)
Name one major artery that supplies the breast and the vessel that artery branches from
Internal thoracic artery (branch of subclavian)
Lateral thoracic artery (branch of axillary artery)
Describe the let-down reflex
Suckling signals back via spinal cord causing
- dopamine realse which inhibits lactotroph inhibition in anterior pituitary causing prolactin release and subsequent milk production
- oxytocin release from paraventricular nucleus and supraoptic nucleus causing oxytocin release from posterior pitutiary which increases milk production and activates contraction of myoepithelial cells to cause milk release
- inhibits the arcuate nucleus causing less GnRH to be released inhibiting gondaotroph hormone release and therefore ovarian cycle
What structure differentiates into the male internal genitalia? What cell produce the hormone that promotes maintenance of this structure?
Mesonephric duct
Leydig cells producing testosterone
What are the two histological changes that will occur in fibrocystic change that has been present for a long period?
Apocrine metaplasia (simple cuboidal --> simple columnar epithelium)
Adenosis (increase number of acini per lobule)