Lecture 23, 24 - Lactation

Question 1

Internal structure of the breast

Answer 1

• Adipose tissue called pectoral fat pad
• coopers ligaments support breasts (less supportive with age and hormones)
• contains lobes containing milk secreting lobules
• lactiferous duct runs towards the nipple and expands at the lactiferous sinus - open onto nipple to allow extraction of milk

Question 2

When do alveoli develop? under influence of what hormone?

Answer 2

Develop at puberty, under influence of oestrogen and progesterone

Question 3

Development of breast during pregnancy

Answer 3

• oestrogen - essential for breast growth
• progesterone - induces side branching of ducts, but also prevents milk production (is a smooth muscle relaxant)
• prolcatin - necessary for alveolar developments but also stimulates caesin and lacta albumin mRNAS
• Insulin and cortisol - stimulate alveolar epithelial cell division

-way more alveolar form for pregnancy , and ductile system grows

Question 4

Endocrine control of lactation

Answer 4

Dopamine inhibits prolactin

• When get suckling, get inhibition of dopamine, so stimulation of prolactin
• VIP is also produced after suckling and induces prolactin secretion
• prolactin stops fsh and lh production
• oxytocin - contraction of myoepithelial cells of alveoli cause ejection of milk into ducts

Question 5

Stages of lactation

Answer 5

stage 1 - mid gestation to day 2 -preparation, however progesterone inhibits this till after birth
stage 2- large scale milk prodcution, alpha lactoalbumin increase
galactopoeisis- maintence and establised milk secretion
involution - aprroax 40 days after lsat feed - due to build up of inhibitory substances

Question 6

Colustrum

Answer 6

• initial milk secretion
• has less fat and sugar than mature milk
• more protein e.g igA - immune protection

Question 7

Components of milk

Answer 7

Phagocytes, lymphocytes - immune protection
Fat - energy, also visual acuity 
Enzymes - help digest of fat
lactose - main cab - energy 
Proteins - immune

Question 8

Advice for breast feeding

Answer 8

• Up to 6 months - will prolong duration of amenorrhea, weight loss
• Bonding with offspring
• helps involution of uterus

Question 9

Mother beneficial

Answer 9

-protect against type 2 diabates, breast and ovarian cancer

Question 10

Benefit to baby

Answer 10

• dont overfeed
• have all the right nutrients
• babies are leaner
• rpotect against obeisty
• morbiity and mortality decreased - hasa immunoglobulins (e.g gi infections, otitis media, asthma)
• enhances cognitive ability - DHA
• However - can get HIV transmission - risk in poorer countries

Question 11

Breast feeding - drugs

Answer 11

alcohol - levels are similar in milk , can have feeding problems
Caffeine - readily enters milk , cannot process it as well as adults