Session 11 - The breast Flashcards
What does each lobule of the breast contain?
Alveoli, blood vessels and lactiferous ducts
What is responsible for milk let down?
myoepithelial cells
How much colostrum is secreted per day in the first week?
40 ml/day
What is the purpose of collustrum?
Provides protein, and immunoglobins for passive immunity
How long is mature milk produced post birth?
As long as the baby suckles
Name the 2 proteins found in mature milk
lactoglobulin and lactalbumin
Where does the synthesis of milk take place?
in the alveolar cells
Describe how breast tissue develops from bith to pregnancy
Birth - few lactiferous ducts only
Puberty - more oestrogen = more ducts and forming of alveoli
Pregnancy - high progesterone:oestrogen ratio develops alveoli more, hypertrophy of ductular-lobular-alveolar system and prominent lobules form. Alveolar cells differentiate to be able to produce milk in mid gestation.
What is the purpose of suckling?
Initiates and maintains secretion by a neuro-endocrine reflex by mechanically stimulating receptors in nipple.
What happens at birth to levels of hormones? What hormone does the breast become responsive to?
Oestrogen and progesterone fall
Breast becomes responsive to prolactin
Describe how suckling promotes release of milk
Mechanical stimulation results in impulses travelling to hypothalamus and reducing secretion of dopamine and vaso-active intestinal peptide, promoting prolactin secretion.
Describe the hormonal control of milk let down. How does this hormone release milk and what other important function does it have?
Let down caused by increase in secretion of oxytocin.
Oxytocin contracts myoepithelial cells surrounding alveoli, ejecting milk. Also keeps uterus clamped down on open placenta blood vessels
How does cessation of lactation occur?
If suckling stops, prolactin levels decrease. Also milk in breast builds up and causes turgor induced damage to ducts.
What happens to breast tissue as women get older? why is this good for mammograms?
Interlobular stroma replaced by adipose tissue. Mammograms easier to interpret
Where can 3rd nipples occur?
Along the milk line
What characteristics of pain in the breast suggest pathology? What could it be?
Non-cyclical and focal. Could be ruptured cysts, injury or inflammation
What are worrying features of a palpable mass? Would could it be?
If hard, craggy, and fixed. COuld be invasive carcinomas, fibroadenomas, cysts
When is nipple discharge concerning? What could it be?
If occurs spontaneously and unilateral
Could be pituitary adenoma or side effect of OCP
During what ages and when are women invited for breast screening?
50-70 every 3 years
What age do fibroadenomas occur most often>
<30
what age do phyllodes tumours most likely occur?
60s
What age does breast cancer most likely occur?
rare before 25, inidence increases with age.
77% occurs in women >50
What organism causes acute mastitis?
Staphylococcus aureus
