Breast and Lactation Flashcards Preview

Biology > Breast and Lactation > Flashcards

Flashcards in Breast and Lactation Deck (20):
1

What makes up the external structures of the breast?

-Areola
-Montgomery tubercles
-Nipple

2

What is the areola?

-The area of pigmentation

3

What are Montgomery's tubercles?

It secretes substances to lubricate the nipple during pregnancy/breastfeeding.

4

What are the nipples?

Nipples are a highly sensitive erectile structure and within it are plain muscle fibres that act as a sphincter to avoid leakage.

5

What makes up the internal structures of the breast?

-Lobes
-Lobules
-Alveoli

6

What are the lobes of the breast?

16-20 lobes are divided into bands of fibrous tissue. Each lobe contains a lactiferous duct leading to a lactiferous sinus. It is here that that milk is stored.

7

What are the lobules of the breast?

Lobules- each lobe is divided into lobules each of which contains a lactiferous duct and alveoli is situated.

8

What are the alveoli of the breast?

Alveoli- are composed of milk-secreting cells → acini. Enclosing each alveoli are myoepithelial cells which have the ability to contract under the influence of hormones → oxytocin. Squeezing milk into the lactiferous ducts.

9

What happens around the 6th week of pregnancy to the breast?

From the 6th week of pregnancy, the breast undergoes enlargement and develops in response to the increasing levels of the hormones of pregnancy.
Oestrogen is responsible for the growth of lactiferous ducts and tubules.
Progesterone, prolactin and human placental lactogen (HPL) result in the proliferation and enlargement of the alveoli
Blood supply to the breast increases → visible veins appearing on surfaces.

10

What happens around the 12th week of pregnancy to the breast?

nipples and areola have become more pigmented
Montgomery’s tubercles have become more pronounced and begin secreting lubricants.

11

What happens around the 16th week of pregnancy to the breast?

Colostrum (highly nutritious and contains many immunoglobulins) has been formed under the influence of HPL and prolactin → high levels of oestrogen and progesterone prevent milk productions.
Because colostrum is formed in early pregnancy, it is available to the neonate after delivery.

12

What happens after labour to the breast?

After the third stage of labour has been completed and the placenta is out oestrogen and progesterone level drops and initiates lactation.

13

What happens during the postnatal period to the breast?

Colostrum continues to be produced for the first day or two delivery and gradually changed in composition to milk.
Encouraged by suckling the neonate from birth.
By the 3rd or 4th day postnatal, the breasts become full and colostrum changes to milk which may make breasts sore.

14

What are the two hormones involved in lactation?

Prolactin from the anterior lobe of the pituitary gland influences the production of milk.
Oxytocin from the posterior lobe controls the ejection of the lobe.

15

What is the neuroendocrine response?

BABY SUCKLES/CRY/THOUGHT OF BABY ← stimulation → NERVE IMPULSES → PITUITARY GLAND STIMULATED → HORMONES (OXYTOCIN/PROLACTIN) -oxytocin acts on the myoepithelial cells surrounding the alveoli→ BOTH BREAST RECEIVE MESSAGE

16

What will frequent breastfeeding maintain?

Frequent breastfeeding including night feeds will maintain good prolactin levels.

17

What is the role of prolactin during lactation?

Tells lactocytes to make milk
Produces calmness and reduces stress
Mothering behaviour stimulated
Needs to be stimulated early and frequently to ensure long term production
When baby attaches properly - sensory impulses pass from the nipple to the brain → prolactin secreted → acini cells produce milk

18

What is the role of oxytocin during lactation?

Expels milk from muscle cells
Pulsatile action
Inhibited by stress
Feeling of loves and wellbeing

19

What is the role of feedback inhibitor lactator during lactation?

Secreted as part of the milk
Build up of FIL blocks milk production
Removing FIL allows milk production

20

Acini cells in breast tissue are stimulated to secrete milk by

Prolactin