The Breast Flashcards
Where is the Leutenising hormone released from?
Released from the anterior pituitary gland
Where is Prolactin released from?
Released from the anterior pituitary gland
Where is Oestrogen released from?
Ovaries, Adrenal gland, Placenta
Where is Progesterone released from?
Ovaries, Adrenal gland, Placenta
Where is Human Placental Lactogen released from?
Placenta
The primary milk ducts are produced by what Gestational week?
32 weeks gestation
At what gestational week do the milk lines form from the axilla to the groin?
4 weeks gestation
After the thickening and inward growth into the chest wall at 7-8 weeks gestation, what happens at weeks 12-16?
Differentiation, where the epithelial cells form mammary buds and branch into alveoli
After the alveoli are formed at 12-16 weeks, what happens to them at weeks 28-32?
Canalisation of these branches and primary milk ducts form
In the final stages of pregnancy, following canalisation, what happens?
Colostrum develops, and ducts open into the nipple. Nipple / areola becomes pigmented
Female breast growth is different to male breast growth because of what hormone?
Human growth hormone
What hormone allows the breast ductal system to develop and differentiation, so the ducts lengthen and branch?
Oestrogen
Which hormone allows nipple growth?
Prolactin
Breasts are located between which ribs?
2nd and 6th intercostal spaces
What is the name of breast tissue which extends towards the Axilla?
Axillary tail of Spence
What is the role of the Tubules of Montgomery?
Secrete lipoid fluid to keep the nipple lubricated & olfactory stimulus
The areola has how many sebaceous glands?
20
What is the name of glandular tissue found in the breast at the terminus of the ductules?
Acini / alveoli
How is milk ejected into ductules?
Myoepithelial cells contract
Which muscle lies posterior to the breast?
Pectoralis major
What is the name of cells which line each alveoli?
Lactocytes
What is the arterial supply of the breast tissue?
- Internal mammary artery (60%)
- Lateral thoracic artery (30%)
What is the nerve supply of the breast tissue?
Branches from 2nd to 6th intercostal nerves
What is the lymphatic drainage of the breast tissue?
Axillary nodes
When does involution of the breast occur?
40 days after last breastfeed
When does Lactogenesis I start? What happens during Lactogenesis I?
- Starts mid to late gestation
- Prolactin is secreted from APG, and alveoli differenates into secretory cells for mik production
- Fat droplets accumulate in lactocytes and move into alveoli
What hormones inhibit milk secretion?
Progesterone / Oestrogen (from the placenta)
When does Lactogenesis II start? Why?
It is triggered by the birth of the child, due to the removal of the Placenta and inhibiting Progesterone, causing +++[PRL]
Lactation moves from endocrine to autocrine
When does Lactogenesis III start?
8-9 days post-partum
Is Lactogenesis III under endocrine or autocrine control?
Autocrine control
Describe the neuroendocrine control of lactation (milk production) when a baby suckles at its mother’s breast
Suckling leads to stimulation of hypothalamus:
- Supression of PIF
- Upregulation of PRF
This leads to release of Prolactin which produces milk
What hormone is found within milk which if not expressed, would prevent further milk being produced?
Feedback Inhibitor of Lactation
Where is Oxytocin released from?
Posterior Pituitary Gland
What is the “Prolactin Receptor Theory”?
Prolactin Receptors in lactocytes distort in shape when breasts are full, hence prolactin cannot enter lactocytes and milk production is decreased
Which hormone stimulates milk ejection from the breast?
Oxytocin
