The Breast

Question 1

Where is the Leutenising hormone released from?

Answer 1

Released from the anterior pituitary gland

Question 2

Where is Prolactin released from?

Answer 2

Released from the anterior pituitary gland

Question 3

Where is Oestrogen released from?

Answer 3

Ovaries, Adrenal gland, Placenta

Question 4

Where is Progesterone released from?

Answer 4

Ovaries, Adrenal gland, Placenta

Question 5

Where is Human Placental Lactogen released from?

Answer 5

Placenta

Question 6

The primary milk ducts are produced by what Gestational week?

Answer 6

32 weeks gestation

Question 7

At what gestational week do the milk lines form from the axilla to the groin?

Answer 7

4 weeks gestation

Question 8

After the thickening and inward growth into the chest wall at 7-8 weeks gestation, what happens at weeks 12-16?

Answer 8

Differentiation, where the epithelial cells form mammary buds and branch into alveoli

Question 9

After the alveoli are formed at 12-16 weeks, what happens to them at weeks 28-32?

Answer 9

Canalisation of these branches and primary milk ducts form

Question 10

In the final stages of pregnancy, following canalisation, what happens?

Answer 10

Colostrum develops, and ducts open into the nipple. Nipple / areola becomes pigmented

Question 11

Female breast growth is different to male breast growth because of what hormone?

Answer 11

Human growth hormone

Question 12

What hormone allows the breast ductal system to develop and differentiation, so the ducts lengthen and branch?

Answer 12

Oestrogen

Question 13

Which hormone allows nipple growth?

Answer 13

Prolactin

Question 14

Breasts are located between which ribs?

Answer 14

2nd and 6th intercostal spaces

Question 15

What is the name of breast tissue which extends towards the Axilla?

Answer 15

Axillary tail of Spence

Question 16

What is the role of the Tubules of Montgomery?

Answer 16

Secrete lipoid fluid to keep the nipple lubricated & olfactory stimulus

Question 17

The areola has how many sebaceous glands?

Answer 17

20

Question 18

What is the name of glandular tissue found in the breast at the terminus of the ductules?

Answer 18

Acini / alveoli

Question 19

How is milk ejected into ductules?

Answer 19

Myoepithelial cells contract

Question 20

Which muscle lies posterior to the breast?

Answer 20

Pectoralis major

Question 21

What is the name of cells which line each alveoli?

Answer 21

Lactocytes

Question 22

What is the arterial supply of the breast tissue?

Answer 22

• Internal mammary artery (60%)

- Lateral thoracic artery (30%)

Question 23

What is the nerve supply of the breast tissue?

Answer 23

Branches from 2nd to 6th intercostal nerves

Question 24

What is the lymphatic drainage of the breast tissue?

Answer 24

Axillary nodes

Question 25

When does involution of the breast occur?

Answer 25

40 days after last breastfeed

Question 26

When does Lactogenesis I start? What happens during Lactogenesis I?

Answer 26

• 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

Question 27

What hormones inhibit milk secretion?

Answer 27

Progesterone / Oestrogen (from the placenta)

Question 28

When does Lactogenesis II start? Why?

Answer 28

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

Question 29

When does Lactogenesis III start?

Answer 29

8-9 days post-partum

Question 30

Is Lactogenesis III under endocrine or autocrine control?

Answer 30

Autocrine control

Question 31

Describe the neuroendocrine control of lactation (milk production) when a baby suckles at its mother’s breast

Answer 31

Suckling leads to stimulation of hypothalamus:

• Supression of PIF
• Upregulation of PRF

This leads to release of Prolactin which produces milk

Question 32

What hormone is found within milk which if not expressed, would prevent further milk being produced?

Answer 32

Feedback Inhibitor of Lactation

Question 33

Where is Oxytocin released from?

Answer 33

Posterior Pituitary Gland

Question 34

What is the “Prolactin Receptor Theory”?

Answer 34

Prolactin Receptors in lactocytes distort in shape when breasts are full, hence prolactin cannot enter lactocytes and milk production is decreased

Question 35

Which hormone stimulates milk ejection from the breast?

Answer 35

Oxytocin