Anatomy of Breast, Milk Production, And Milk-ejection.ppt

8/10/2019 Anatomy of Breast, Milk Production, And Milk-ejection.ppt

1/23

Anatomy of BreastMilk Production

Milk-ejection

Deepak Ghimire


2/23

Anatomy of Breast

The nipple is the central areathrough which the milk ductsopen.

The areola is the circular darkarea around the nipple.

The "bumps" on the areola an

nipple are Montgomery'stubercles.

These tubercles contain theopening of sebaceous and sweglands (Montgomery glands)that secrete lubricatingsubstances for the nipple.


3/23

Milk production

Milk is produced in the alveolu The alveolus is made up of gla

cellsaround a central duct.

The milk is produced by the glacells.

Surrounding the gland cells ar

the myoepithelial cellswhichcontract to cause milk ejectioninto the milk duct.

The milk then travels down thelactiferous ducts.

Lateral view with anatomical overlay


4/23

Milk production

Milk is stored largely inthe alveoli with little

storage in the ducts

between breastfeedings

Mothers continue tomake milk between

feedings and they make

more milk during feedin


5/23

Milk production

When an infant breastfeeds, the infadraws the nipple and the areola intotheir mouth.

The mother's nipple elongates toabout twice its normal length.

The nipple height is compressedbetween the tongue and the palate.

Milk is ejected about 0.03 secondsafter maximum nipple elongation

http://www.breastfeedingbasics.org/cgi-bin/getcite.cgi?name=SMITH1988


6/23

LACTATION

Lactationis the process by which milkis synthesized and secreted from themammary glands of the postpartumfemale breast in response to an infantsucking at the nipple

Four Important Hormones areInvolved Estrogen

progesterone

prolactin

oxytocin


7/23

Stages of lactation

There are four stages of lactation:

1. Mammogenesis(growth of the breasts)

2. Lactogenesis(the functional change of the breasts so that they cansecrete milk)

3. Galactopoiesis(maintaining the production of milk)

4. Involution(the termination of milk production).

http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496
http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496http://www.fastbleep.com/medical-notes/o-g-and-paeds/16/79/496


8/23

ROLE OF HORMONES

Progesterone influences the growth in size of alveoli and lobes high levels of progesterone inhibit lactation before birth.

Progesterone levels drop after birth

this triggers the onset of copious milk production

Estrogen

stimulates the milk duct system to grow and differentiate Like progesterone, high levels of estrogen also inhibit lactation.

Estrogen levels also drop at delivery and remain low for the first severalmonths of breastfeeding

Breastfeeding mothers should avoid estrogen-based birth control methods, spike in estrogen levels may reduce a mother's milk supply.


9/23

ROLE OF HORMONES

Prolactin contributes to the increased growth and differentiation

the alveoli

also influences differentiation of ductal structures

High levels of prolactin during pregnancy and

breastfeeding also increase insulin resistance, increasegrowth factor levels (IGF-1) and modify lipid metabolismin preparation for breastfeeding.

During lactation, prolactin is the main factormaintaining tight junctions of the ductal epithelium and

regulating milk production through osmotic balance.


10/23

ROLE OF HORMONES

Oxytocin contracts the smooth muscle of the uterus during a

after birth

After birth, oxytocin contracts the smooth muscle

layer of band-like cells surrounding the alveoli tosqueeze the newly produced milk into the ductsystem.

Oxytocin is necessary for the milk ejection reflex,

or let-downto occur.


11/23

Importance of Reflexes in baby


12/23


13/23

Role of Oxytocin


14/23

Role of prolactin and oxytocin

Prolactin signals for milk

production

oxytocin operates to push out the

breastmilk that accumulates in the

breast ducts


15/23

Mechanism of Milk Production

Suckling infants compress the areola with

their gums which stimulates oxytocinrelease.

The oyxtocin release causes an increase inthe diameter of the milk ducts andmovement of milk in the ducts toward thenipple.

Mothers may feel a sensation of pins andneedles, pressure, or pain in the breastwith milk ejection.

This sensation may disappear as lactationcontinues over a several month period oftime.


16/23

Initial milk ejection ismanifested by

an increase in diameter of

the milk duct

movement of the milk fatglobules

occurred at an average of

50 seconds after suckling

began


17/23

LEVEL OF HORMONES


18/23

MECHANISMOF BREAST

MILK

PRODUCTION


19/23

Action of hormones

When a baby sucks on the nipple, the stimulation is transmitted to thpituitary gland and hormones called prolactin and oxytocin are

produced.

Prolactin signals for milk production

oxytocin operates to push out the breastmilk that accumulates in thebreast ducts.

Breastmilk is released when the baby sucks on the nipple.

It may not work at first, as both baby and mother are beginners, but

with repetition, both will grow more adept at it.


20/23


21/23

Milk j i fl


22/23

Milk ejection reflex

This is the mechanism by which milk is transportedfrom the breast alveoli to the nipple.

Suckling by the baby stimulates theparaventricularnuclei and supraoptic nucleus in the hypothalamus,which signals to the posterior pituitary gland to

produce oxytocin. Oxytocin stimulates contraction of the myoepithelia

cells surrounding the alveoli, which already hold mil

The increased pressure causes milk to flow through

the duct system and be released through the nipple


23/23

Anatomy of Breast, Milk Production, And Milk-ejection.ppt

Documents

Transcript of Anatomy of Breast, Milk Production, And Milk-ejection.ppt