breast

Question 1

Appocrine vs Eccrine sweat glands

Answer 1

Eccrine = sweat glands that open directly onto skin surface (Everywhere)

Appocrine = sweat glands that open onto a hair follicle (Armpits, groin, scalp)

Question 2

What is the arterial supply of the breast

Answer 2

[LATERAL SIDE]:
Suclavian artery –> thoraco-acromial trunk –> Axillary artery –> lateral thoracic artery –> lateral mammary branches

[MEDIAL SIDE]:
Subclavian artery –> internal thoracic artery –> medial mammary branches

posterior intercostal arteries

Question 3

What muscles does the breast lie on?

Answer 3

Pec major
serratus anterior
external oblique
rectus abdominis

Question 4

Which lymph nodes drain the:
breast skin
breast tissue
nipple/ areola

Answer 4

skin:
-axillary nodes
-infraclavicular
-inferior deep cervical

tissue:
-axillary
-posterior intercostal
-parasternal

nipple/ areola:
-sub-areolar lymphatic plexus

Question 5

where does the breast extend to/ from vertically/ horizontally

Answer 5

vertically = 2-6th ribs
horizontally= sternum - mid axillary line

Question 6

which nerves supply the breast/ nipple

Answer 6

breast = 4-6th intercostal nerve

nipple = 4th IC nerve

Question 7

What structure does the breast develop from and during which gestational week

Answer 7

From mammary ridge at 5th week of gestation

Question 8

what effect does oestrogen have on breast

Answer 8

Oestrogen = proliferation of mammary ducts/ lobules

Question 9

what effect does progesterone have on the breast

Answer 9

Progesterone = growth or dilation of ducts/ lobes

Question 10

Describe the changes to the breast with hormonal changes in pregnancy

Answer 10

preg= sustained increase in oestrogen + progesterone = proliferation + growth of mammary ducts and stromal tissue + fat

Question 11

Why does lactation NOT occur during pregnancy

Answer 11

High levels of oestrogen + progesterone inhibits lactation (inhibits prolactin)

Question 12

Describe how lactation occurs postpartum

Answer 12

Post preg = drop in oestrogen + proges = production of prolactin in ANT pituitary = production of breast milk

Question 13

What hormone is needed for milk ‘let down’ and how does it work

Answer 13

Oxytocin = contracts myoepithelial cells in breast

Question 14

Where is oxytocin produced and how is it secreted

Answer 14

produced = POSTERIOR pituitary

secretion = baby suckling

Question 15

What is the milk produced in the first 4 days called and what does it contain

Answer 15

Colostrum = high protein + IgA

Question 16

What drugs can pass into breast milk

Answer 16

alcohol
metronidazole
tetracyclines
anticoagulants

Question 17

How does menopause change the breast

Answer 17

Age >35 = reduced oestrogen = less stromal tissue = more fat + fibrotic tissue (less dense)

Question 18

Where do the Coopers ligaments attach

Answer 18

Skin - deep fascia

Question 19

What is a breast lobule

Answer 19

many alveoli (milk producing units) that drain into a lactiferous duct = lobule

Question 20

What is a breast Lobe

Answer 20

many lobules that drain into a common lactiferous duct = Lobe

Question 21

How many lobes can be present in the breast

Answer 21

12-20

Question 22

Where do the lactiferous ducts drain

Answer 22

Each drains into a lactiferous sinus at the nipple