Breast Anatomy

Question 0

Organ

Answer 0

An organ (or viscus) is a collection of tissues joined in a structural unit to serve a common function.

Organs are composed of main tissue, parenchyma, and “sporadic” tissues, stroma. The main tissue is that which is unique for the specific organ, such as the myocardium, the main tissue of the heart, while sporadic tissues include the nerves, blood vessels, and connective tissues.

Question 1

Mammary Glands

Answer 1

A mammary gland is an organ in female mammals that produces milk to feed it offspring.

Question 2

Lactiferous Ducts

Answer 2

Any of the ducts that drain the lobes of the mammary gland at the nipple. There are about 10 duct systems in each breast, each with its own opening at the nipple

Also called galactophore, galactophorous duct, mammary duct, mamillary duct, milk duct.

Question 3

What does the Endocrine system do?

Answer 3

Endocrine system: communication within the body using hormones made by endocrine glands such as the hypothalamus, pituitary gland, pineal body or pineal gland, thyroid, parathyroids and adrenals, i.e., adrenal glands.

Question 4

Oxytocin

Answer 4

The feel good hormone. Ejection (“Let down”) process in milk secretion
Milk is continuously secreted into the alveoli of the breast, however to get the milk from the alveoli and into the ducts it needs to be ejected. Ejection is a neuronal and hormonal reflex involving oxytocin.
Oxytocin is a mammalian neurohypophysial hormone. Produced by the hypothalamus and stored and secreted by the posterior pituitary gland, oxytocin acts primarily as a neuromodulator in the brain.

Question 5

Epithelial Cells.

Answer 5

The first layer is made up of epithelial cells (cells that form the inner layer of mammary ducts), which make and secrete milk.

Question 6

myoepithelium

Answer 6

The second layer is called the myoepithelium and is made of cells that sit next to the epithelial cells. The cells in the myoepithelium (called myoepithelial cells) are a specialized combination of muscle (cells that contract) and epithelial cells (which secrete substances). One of the main functions of the myoepithelium is to contract mammary ducts and push milk through the ducts and out of the nipple

Question 7

Areola

Answer 7

an areola is any small circular area on the body coloured differently from the surrounding tissue. The term is most commonly used to describe the pigmented area on the human breast around the nipple (areola mammae) but it can also be used to describe other small circular areas such as the inflamed region surrounding a pimple.

Question 8

Cooper’s Ligaments

Answer 8

Coopers Drooper’s maintain structural integrity -connective tissue
Coopers Ligaments help hold the breasts up. They are thin bands interwoven into the breast and are not very strong.
They are named for Astley Cooper, who first described them in 1840.

Question 9

Adipose Tissue

Answer 9

body fat or just fat is loose connective tissue composed mostly of adipocytes. Its main role is to store energy in the form of lipids, although it also cushions and insulates the body.

Question 10

“axillary tail of Spence”

Answer 10

center of the axilla, or under arm). It is important to note that a tail of breast tissue called the “axillary tail of Spence” does extend into the axilla.

Question 11

Lobules

Answer 11

Each lobe has 20 to 40 lobules. Small ducts are attached to the lobules. These ducts join together like branches of grape stems into increasingly larger ducts.

Question 12

Lobes

Answer 12

Bunches of grapes. These “bunches” are called lobes. - each breast contains 15 to 20 lobes of glandular tissue, . Then inside the lobes is lobules (small round sacs that produce milk) and ducts (canals that carry milk from the lobules to the nipple openings during breastfeeding

Question 13

Prolactin

Answer 13

Prolactin stimulates milk secretion
new mother nurses her baby, hears her
signals are sent from the nipples to the hypothalamus.
causes a surge in the levels of prolactin released, which lasts for about a hour. Prolactin makes the mammary glands secrete milk into the alveoli. If the surge is absent or blocked as a result of hypothalamus or pituitary gland damage, or if nursing does not continue; the breasts start to lose their ability to produce milk in about a week or two.

Question 14

Lactogensis

Answer 14

Lactogensis is the term meaning the initiation of lactation. This it the process of functional differentiation which mammary tissue undergoes when changing from a nonlactating to a lactating

Question 15

Mammogensis

Answer 15

mammogenesis The development of breast tissue; breast development.

Question 16

There are four stages of lactation:

Answer 16

Mammogenesis (growth of the breasts)
Lactogenesis (the functional change of the breasts so that they can secrete milk)
Galactopoiesis (maintaining the production of milk)
Involution (the termination of milk production).

Question 17

The important hormones involved in lactation are:

Answer 17

prolactin
oestrogens
progesterone
adrenal corticoids (cortisol)
insulin
growth hormone

Question 18

Galactopoiesis

Answer 18

Galactopoiesis starts around 9 days after birth and finishes at the beginning of involution. It is the maintenance of milk secretion controlled by hormones. Breast size starts to diminsh betwwn 6 to 9 months after birth. The rate of milk formation normally decreases after 7-9 months; however milk production can continue for years if the child continues to suckle.

Question 19

There are two main stages of lactogenesis:

Answer 19

Lactogenesis I: the ability of the mammary glands to secrete milk from mid-pregnancy to late pregnancy.
Lactogenesis I starts from mid-pregnancy till 2 days after birth. It involves the differentiation of alveolar epithelial cells and the stimulation of milk synthesis by prolactin.

Lactogenesis II: the formation of large amounts of milk after parturition.
Lactogenesis II starts from day 3 postpartum to day 8. It is triggered by the reduction of progesterone. The breast become full and warm and produce large amounts of milk.

Question 20

Involution

Answer 20

Involution is the loss of secretory function of milk, due to the accumulation of inhibiting peptides. It normally starts 40 days after the last breastfeed. The epithelial cells no longer require their secretory properties so they are removed by the process of apoptosis and replaced by adipocytes.

Question 21

WHO recommendations for breastfeeding

Answer 21

Breastfeeding should begin within an hour after birth.
Breastfeeding should be “on demand”, day and night.
Bottles or dummies should be avoided.
Exclusive breastfeeding (only breast milk given-not even water consumed) should occur until the baby is 6 months.
After 6 months complementary breastfeeding (breast milk and other foods) should occur until the age of 2.
New mothers should have at least 16 weeks off work after birth, so that she can rest and breastfeed her baby.

Question 22

Progesterone

Answer 22

Progesterone is involved in the last stages of mammogenesis after the ductal system has grown. It acts with the other hormones to develop the breast lobules and alveoli, and adapts the alveoli to have secretory properties.Brief timeline of milk secretion

During pregnancy the high levels of progesterone and oestrogens inhibit milk secretion.

After parturition, the loss of the placenta reduces the levels of oestrogen and progesterone in the mother’s blood so that the hormones no longer have an inhibitory effect on the breasts. Over the next 1-7 days the breast begin to secrete a greater volume of milk instead of colostrum.

Question 23

Colostrum

Answer 23

During the last few days before parturition and some days after, a fluid called COLOSTRUM is secreted. Colostrum has a different composition to milk and is produced at a slower rate. It is made up of lactose and proteins; however milk is made of lactose, proteins and fat.

Question 24

Colostrum Composition

Answer 24

One of the major purposes of colostrum is to aid in the formation of the “good” bacteria, or Bifidus flora, in the GI tract. It also eases the . Colostrum is abundant in antibodies to protect the baby against bacteria and viruses in the birth canal and from human contact.
Colostrum has a laxative effect movement of meconium -helps to prevent neonatal jaundice by clearing the bilirubin from the gut.

Question 25

There are 3 main stages that your milk goes through:

Answer 25

Colostrum, Transitional milk and Mature milk.

Question 26

Transitional Milk

Answer 26

During the following two weeks, the milk increases
The immunoglobulins and protein contents decrease whereas fat and sugar contents increase. At this time, the breasts may feel full, hard and heavy. This normal engorgement of the mother’s breasts – sometimes referred to as „coming-in“ of the milk – can be alleviated by frequent feedings.

Question 27

Mature Milk

Answer 27

Mature milk looks thinner and more watery than cow’s milk which might be sometimes confusing. But it contains all the nutrients needed for healthy development of the baby. Breastmilk is never „too thin“. Mature milk changes during the length of a single feed to exactly suit the needs of a baby.

The milk that flows at the beginning of a feed is low in fat and high in lactose, sugar, protein, vitamin, minerals and water. As the feed goes on, the milk changes to contain more fat and less sugar.