Breast anatomy Flashcards
What are breasts composed of?
Varying proportions of fat and glandular tissue separated by connective tissue, into lobes - each lobe is separated into lobules which consist of alveoli and ducts
What are the 3 constituents of the surface anatomy?
Nipple
Areole
Montgomery tubercles
What are lobes?
Approx. 4-18 lobes in each breast composed of glandular tissue divided by connective tissue and adipose layer
What are lobules?
Subdivision of each lobe consisting of alveoli and lactiferous ducts
Collections of 10-100 alveoli form 1 lobule
What are alveoli and what do they do?
The basi glandular unit of the breast
Contain acini cells responsible for secreting milk and are surrounded by myo-epithelial cells composed of smooth muscle
Why are lymphocytes ans monocytes found in the alveoli?
They are found wedged between the secretory (acini) cells of the alveoli and have migrated there
Play a role in local production of antibodies in the form of immunoglobulin A (IgA) for secretion into breast milk
What is the ductal system?
Complex network of lactiferous ducts - arise from alveoli and unite to from larger ducts
Transports milk to the nipple
What are the 3 different types of fat in the breast and where are they found?
Subcutaneous fat - near the surface of the breasts
Intraglandular fat - around the ductal network
Retroglandular fat - behind the ductal network, towards the ribs
What are coopers ligaments?
Ligaments that connect the breast tissue to the skin
How is blood supplied to the breasts?
Internal and external mammary glands
Intercostal arteries
What is the foetal breast development?
Branching morphogenesis - development of the ductal system in utero
Mammary-specific cells present from 4-6 weeks gestation (irrespective of sex)
What is the neonatal breast development?
From birth, some glandular tissue is present, and milk may be produced - known as galactorrhea of the newborn
Up to 70% of neonates have unilateral or bilateral breast enlargement or a transliteration secretion of milk
How do breasts develop at puberty?
Sexually dimorphic breast development - occurs under the influence of sex hormones
Usually the first secondary sex characteristics
Ductal development branching and lobular development occurs
Nipple size increases and the primary areola becomes pigmented
How do breasts develop in pregnancy?
Glandular development occurs under the influence of progesterone
Ductal development occurs under the influence of oestrogen
Colostrum is synthesised but lactation is suppressed under the influence of placental hormones
