Anatomy and Physiology

Question 1

What happens to the breasts at 6 weeks gestation?

Answer 1

Oestrogen promotes the growth of the lactiferous ducts.
Progesterone, prolactin and human placental lactogen (HPL) leads to proliferation and enlargement of the alveoli. This can cause tingling, sensitivity and heaviness of the breast.
There is an increased blood supply making veins become visible on the surface of the breast.
Pollard (2017)

Question 2

What happens to the breasts at 12 weeks gestation?

Answer 2

Greater pigmentation of the areola and nipples which is caused by increased melanocytes, and they become red/brown in colour.
The Montgomery’s tubercles also become more prominent and begin to excrete a serous lubricant to protect the nipple and areola.
Pollard (2017)

Question 3

What happens to the breasts at 16 weeks gestation?

Answer 3

Colostrum is produced (Lactogenesis I) under the influence of prolactin and HPL.
Complete milk production is suppressed by the high levels of oestrogen and progesterone, but some women may find they secrete clear fluid early on.
Pollard (2017)

Question 4

What happens to the breasts at 24 weeks gestation?

Answer 4

The secondary areola is formed around the areola.

Pollard (2017)

Question 5

When are breasts considered to achieved their full development?

Answer 5

Lactation

Pollard (2017)

Question 6

Lactogenesis

Answer 6

Is the initiation of milk production. There are three phases:
- 2 hormonal/neuroendocrine
- autocrine or local control
Pollard (2017)

Question 7

Lactogenesis I

Answer 7

Occurs around 16 weeks when colostrum is produced by lactocytes under neuroendocrine control
Pollard (2017)

Question 8

Lactogenesis II

Answer 8

Is the onset of milk production.
Initiated by the expulsion of the placenta and membranes which causes a sudden drop in progesterone, oestrogen, HPL and PIF.
This allows the prolactin levels to increase and bind with prolactin receptors in the walls of the lactocytes and milk synthesis begins.
Pollard (2017)

Question 9

What does skin to skin contact at birth stimulate?

Answer 9

Stimulates the production of prolactin and oxytocin.

Pollard (2017)

Question 10

Why does there need to be early and regular breastfeeding?

Answer 10

Inhibits the production of PIF and stimulates the production of prolactin - prolactin receptor theory
Pollard (2017)

Question 11

Lactogenesis III

Answer 11

Indicates the autocrine regulation where supply and demand regulate milk production. Milk is controlled by breastmilk removal.
Pollard (2017)

Question 12

Feedback Inhibitor of Lactation (FIL)

Answer 12

As part of lactogenesis II, the whey protein FIL is secreted by the lactocytes which regulate milk production at a local level. As the alveoli distend, there is a build up of FIL and milk synthesis is inhibited.
When breastmilk is effectively removed and the concentrations of FIL reduced, milk synthesis resumes.
Can occur in one or both breasts.
This is a negative feedback response.
Pollard (2017)

Question 13

Prolactin

Answer 13

Is the main hormone for the establishment and maintenance of breastmilk production. It is released into the blood from the anterior pituitary gland in response to suckling or nipple stimulation. This primes and stimulates the prolactin receptor sites on the walls of the lactocytes to synthesise milk.
Pollard (2017)

Question 14

When are prolactin levels at their highest?

Answer 14

45 minutes after a feed.
The levels peak at night thus night feeds must be encouraged to promote milk production
Pollard (2017)

Question 15

Prolactin receptor theory

Answer 15

Suggests that milk removal in the early days increases the number of prolactin receptor sites activated, therefore improving milk production.
Pollard (2017)

Question 16

Oxytocin

Answer 16

Released from the posterior pituitary gland and stimulates the contraction of myoepithelial cells surrounding the alveoli to eject milk through the lactiferous ducts. This is known as the let-down, oxytocin or ejection reflex.
Pollard (2017)

Question 17

What may women experience when the let down reflex occurs?

Answer 17

May feel a tingling sensation in the breast and uterine contractions causing an increase in vaginal bleeding in the first few days.
Pollard (2017)

Question 18

What triggers and inhibits the let down reflex?

Answer 18

In the first few days it is controlled by suckling and also the mother seeing, touching, hearing and smelling her baby.
Over time, it may be triggered by thinking about feeding or hearing another baby cry.
The let-down reflex can be inhibited by stress and anxiety.
Pollard (2017)