Week 11 - Lactation

Question 1

Describe the structure of the breasts

Answer 1

• Mammary glands embedded within lobulated masses of tissue separated by fibrous/adipose tissue
• Lobes contain alveoli, lactiferous ductules and blood vessels

Question 2

What is mammogenesis? Describe what happens

Answer 2

• The preparation of the breasts for lactation during pregnancy
• Hypertrophy of the duct-lobe-alveolar system

Question 3

When is milk production possible in pregnancy?

Answer 3

-From trimester 2

Question 4

Why does pregnancy favour growth of breasts over secretion of milk?

Answer 4

-High progesterone:oestrogen

Question 5

What is lactogenesis? Describe this stage

Answer 5

• Synthesis of milk
• Fats and proteins and sugars are secreted and synthesised by sER and golgi.
• Neutrophils/macrophages enter alveolar space to protect against infection

Question 6

What is galactokinesis? Describe this

Answer 6

• Ejection of milk

- Let-down reflex -> alveoli are surrounded by myoepithelia and contract in response to oxytocin

Question 7

What stimulates oxytocin release in order to stimulate the let-down reflex?

Answer 7

-Mechanical stimulation of breast and nipple eg suckling

Question 8

What is galactopoesis? Explain how this works

Answer 8

• Maintenance of lactation
• Prolactin is stimulated by suckling and causes the production of milk for the next feed which is stored in the alveoli and ducts (secretory change)

Question 9

State some situations when lactation would cease

Answer 9

• Stopped suckling -> lost feedback of prolactin
• Pain
• Menstruation
• Prolactin supression
• Age due to breast involution

Question 10

Descrbe the changes in milk which occur from a few days to mature milk

Answer 10

• Begins as colostrum which has a high protein and igG count

- Turns into mature milk with an increase in water and fats and proteins such as lactalbumin