Lactation

Question 1

A complex process, proper to the mother and child dyad, and including numerous variables ranging from psychological aspects to the secretory functioning of the mammary epithelial cells, all contributing to successful breastfeeding

Answer 1

Lactation

Question 2

Structure of mammary gland

Answer 2

Has multiple lobes containing your lactiferous ducts and sinuses ending up in the nipple

Question 3

Where should the baby’s mouth attach during breastfeeding?

Answer 3

It should be at the areolar side so that when it squeezes on it, the sinuses will be squeezed, as well.

If the baby just nibbles with poor attachment on the nipple, it’s not effective.

Question 4

Epithelial layers of the alveoli and ducts:

Answer 4

> Apical luminal epithelial cells
-where milk is produced & ejected

> Basal myoepithelial cells

Question 5

Fundamental secretory unit of the breast? What does it secrete?

Answer 5

Alveoli

-secretes milk

Question 6

Breastmilk vs. Cow’s milk

1. Protein content
2. Which is more preferred. Why?

Answer 6

1. 3x higher and protein content ng cow’s milk

2. Breastmilk. There could be some intolerance to the cow’s milk, particularly cow’s milk allergy

Question 7

Would size of the breasts matter in breastfeeding?

Answer 7

No! Size is just a factor of the amount of fat in the breast.

Question 8

1st milk that can be seen?

Answer 8

Colostrum

Question 9

Secretory differentiation of MECs stages

Answer 9

1. Initiation/Lactogenesis I
   - Leads to formation of colostrum!!!
   - Inc production of milk due to prolactin (once estrogen and progesterone levels are low)
2. Activation or Lactogenesis II
   - During the activation process, after giving birth, the rapid withdrawal of your progesterone and estrogen will now lead to higher concentrations of PRL that will now start the breastfeeding process

Question 10

Breastmilk

Types

Answer 10

Colostrum

• First 4 days
• Color yellow due to high levels of protein
• THE BEST!

Transitional milk
-10-15 days

Mature milk
-15+ days

Question 11

Important component of the breastmilk not seen in cow’s milk?

Answer 11

Secretory IgA

>For the immune functions of the baby!

Question 12

5 major routes how the milk goes out to the alveolar lumen and from there will go to the lactiferous ducts then goes out to the baby

Answer 12

1. Secretory pathway
   Proteins (lactalbumin and casein) are synthesized in the ER -> sorted in the GA -> + Ca2+ -> lactose is generated -> + H2O -> ready for exocytosis (to the lumen of the alveoli ready to be transported to the ducts)
2. Transcellular endocytosis/exocytosis
   >Basolateral membrane takes up the immunoglobulins and receptor-mediated endocytosis
3. Lipid pathway
   >Epithelial cells synthesize SCFAs -> Form lipid droplets then they move to the apical membrane -> As they move, it takes with it the membrane (called milk fat globule membrane) -> they get pinched off
4. Transcellular salt and water transport through channels and transporters
   > You call it transcellular salt and water
   You know water follows the lactose that is present so it’s transcellular here and you now have the paracellular pathway in between via the tight junctions
   Caution of what’s there: Leukocytes can also squeeze between cells and enter the milk
   What is that to us? This can be source of contamination.
   If there’s an infection in the mom through this pathway, it can pass to the breastmilk and it can be taken by the baby
   Thus, there are certain diseases where breastfeeding is strongly contraindicated bc of that
   E.g. Active tuberculosis
   Note: Breastfeeding advocates believe that the advantage of pure breastfeeding will be greater. Dying from the diarrhea/infection for not breastfeeding will have a higher incidence than dying from HIV which makes sense.
5. Paracellular pathway
   >In between via the tight junctions
   >For ions and water

Question 13

During pregnancy, these hormones will stimulate breast development

Answer 13

Estrogen, progesterone, HPL, GH variant (GH-V)

Question 14

How do you maintain milk production? Is pumping enough?

Answer 14

Suckling activity of the infant will stimulate PRL and OT to maintain it.

In pumping, they just negatively suction the milk lang but nothing is stimulating nipple. It’s the stimulation to the nipple that creates this effect.

Question 15

Effects of these hormones in lactation?
1. Mammogenic Hormones

2. Lactogenic Hormones
3. Galactokinetic Hormones
4. Galactopoietic Hormones

Answer 15

1. Mammogenic Hormones (promote cell proliferation)
   >Lobuloalveolar Growth
   >Ductal Growth
2. Lactogenic Hormones
   - promote initiation of milk production by alveolar cells
3. Galactokinetic Hormones
   - promote contraction of myoepithelial cells and thus, milk ejection
   e. g. OT, AVP
4. Galactopoietic Hormones
   -maintain milk production after establishment
   E.g. PRL (1’), and Cortisol/Other metabolic hormones

Question 16

Prolactin

1. Synthesized and release in?
2. Effects
3. Powerful stimulus
4. Actions
5. Role of ANS

Answer 16

1. AP
2. Essential for milk production
3. Sucking
4. Actions: Ma, GaLa
   Mammogenic, Galactopoietic, Lactogenic
5. Afferent neural pathway inhibits dopaminergic neurons in the hypothalamus.
   When this is inhibited, you release PRL bc dopamine (DA) inhibits PRL release normally

Question 17

Three effect of suckling on the release of PRL, OT, and GnRH

Answer 17

When the baby sucks, it will form synaptic connections with cord that will eventually will eventually lead to simulation of higher center - signals to the brain

1st effect: in the arcuate nucleus
>Afferent input from the nipple inhibits the release of DA leading to increase in PRL
= “Dopamine inhibition, arcuate nucleus”

2nd effect: Effect on the synapses or provisions given by your cord to the PREOPTIC and PARAVENTICULAR nucleus. This will lead to the release of your OT in the posterior pituitary gland.
>Effect of OT: milk ejection and milk let down
= “Effect on preopetic and paraventicular particularly on the release of your OT”

3rd effect: On the PREOPTIC and ARCUATE meaning to say at this pt, you inhibit GnRH release
>Inhibit GnRH release -> no FSH and LH -> no ovulation/ovarian cycle
-Form of contraception

Question 18

Maintaining breastfeeding

Answer 18

> Not nursing for 1-2 weeks -> fall to nonpregnancy levels

>There will be a time that it will plateau

Question 19

Milk production

Answer 19

Your body will sense the demand so exclusive frequent feeding will enhance milk production

Question 20

What is kangaroo mother care? Advantages?

Answer 20

You have a pouch, put baby inside naked (just give the baby a bonnet for thermoregulation)

Advantages:
>Unlimited access to breastcare
>Thermoregulation

Question 21

What is FIL?

Answer 21

Feedback inhibitor of lactation (FIL)
-If you do not feed to the maximum ability/content (you don’t empty the breast) - small amounts of whey protein can serve as feedback inhibitor of lactation/milk production

SO EMPTY!

Question 22

What is “Lactation Amenorrhea”

Answer 22

> Suckling inhibits the ovarian cycle

>”Nature’s contraceptive”

Question 23

Menopausal breast - what happens during menopause?

Answer 23

> FSH and LH levels are high because estrogen and progesterone are low.
Effect on the breast: There’s some regression because you now have ovarian and endometrial regression.

Question 24

Induced lactation vs. Relactation

Answer 24

Induced lactation

• process by which a nonpuerperal woman is stimulated to lactate
• Goal: NURTURING with the emphasis on nursing, not on “breastfeeding” or nutrition

Relactation
-Process by which a woman who has given birth but did not initially breastfeed is stimulated to lactate; to reinstitute lactation

Question 25

No milk already but want to relactate. What will you do?

Answer 25

You see there’s a tube attached to a syringe/something. It is there just in the nipple so the baby sucks the nipple and then you press on the syringe so the milk will go out so the baby thinks that as he sucks, parang may milk. This will help breastfeeding.