The Breast Flashcards
What is the role of oestrogens in breast development?
Stimulates ductal system proliferation and branching.
What does prolactin influence during breast development?
Nipple growth and lobular-alveolar development.
Which hormone promotes growth of areola during pregnancy?
Serum placental lactogen.
What effect does progesterone have on the breast?
Promotes growth of lobes, lobules, alveoli, and duct widening.
How do ACTH and hGH contribute to mammary growth?
They synergize with prolactin and progesterone.
From which embryonic layers is breast tissue derived?
Ectoderm and mesoderm.
When is complete mammary differentiation fully achieved?
During pregnancy and lactation.
What are milk lines?
Thickened epithelial ridges forming from the 5th week gestation.
What is the difference between breast development in childhood and puberty?
Childhood: isometric; Puberty: allometric.
At what age do primary and secondary ducts form in girls?
10–12 years.
What causes irreversible mammary development in women?
Each reproductive cycle.
Between which ribs is the breast located?
2nd rib to 6th intercostal space.
What are the two major components of the breast?
Parenchyma and stroma.
What determines breast size?
Fat content, not glandular tissue.
What improves latch and helps babies locate the breast?
Tubercles of Montgomery and sebaceous fluid.
What is the main blood supply to the breast?
Internal mammary artery (60%) and lateral thoracic artery (30%).
Where does lymph from the breast mostly drain?
Axillary lymph nodes.
Which nerves innervate the breast?
2nd to 6th intercostal nerves (mainly 4th-6th).
What are the three stages of lactation?
- Development & colostrum
- Onset of milk (32-96 hrs post birth)
- Maintenance.
What triggers colostrum secretion?
Differentiation of alveolar epithelial cells into lactocytes (~16 weeks gestation).
What change triggers onset of copious milk secretion after birth?
Rise in prolactin and fall in pregnancy hormones.
What maintains long-term milk production?
Frequent milk removal and feedback inhibitor of lactation (FIL).
What are lactocytes?
Milk-secreting cells in the alveoli.
What cells surround the alveoli to eject milk?
Myoepithelial cells.
What is prolactin responsible for?
Milk production.
When are prolactin levels highest?
At night and with touch/stimulation.
What is oxytocin responsible for?
Milk ejection (‘let down’).
What can inhibit oxytocin release?
Stress.
What behaviors do prolactin and oxytocin support?
Instinctive mothering and bonding.
What is FIL?
A whey protein that inhibits milk synthesis when breasts are full.
How does pressure in the breast affect milk production?
Flattens cells and receptor sites, reducing prolactin binding.
Name 3 physiological effects of oxytocin.
Lowers BP, reduces stress/pain, improves sleep.
How does oxytocin affect bonding?
Enhances emotional connection between mother and baby.
Can synthetic oxytocin affect natural oxytocin levels?
Yes, it may negatively impact natural production.
What is lactoferrin and its role in milk?
A transfer factor that aids iron absorption.
What creates a low pH in the infant gut?
Bifidus factor promoting growth of Lactobacillus bifidus.
Which enzyme in breastmilk aids fat digestion?
Lipase.
What do breastmilk oligosaccharides do?
Prevent pathogens from adhering to gut wall.
What type of antibodies does breastmilk contain?
SIgA and antibodies from entero- and broncho-mammary pathways.
Does formula contain living cells and immune components?
No—formula is nutritionally adequate but lacks immune protection.
What is a typical sign of mastitis?
Wedge-shaped area of inflammation and tenderness.
What causes non-infective mastitis?
Poor attachment, tight clothing, or milk stasis.
What percentage of mastitis cases are non-infective?
70%.
When does mastitis most commonly occur?
Within the first 3 months postpartum.
What bacteria is often involved in infective mastitis?
Staphylococcus aureus.
Management for mastitis includes?
Breastfeeding, massage, compresses, analgesia, fluids, rest, correct latch.
What is a breast abscess?
A collection of pus often due to untreated mastitis.
How is a breast abscess treated?
Ultrasound-guided aspiration or surgical drainage, plus antibiotics.
