Anatomy of the Breast

Question 1

Breast Development Summary:

Answer 1

• week 5: two parallel ectodermal
  ridges from primitive axilla to
  inguinal
• week 9: ridges disappear apart
  from primary buds on pectoral
  region, which divide into secondary
  buds
• week 26: secondary budes
  developing lumen and terminal
  pouches, no difference between
  sexes at birth

Question 2

Breasts are —– glands. Modified ——.

Answer 2

• mammary glands
• modified sweat gland (apocrine)

Question 3

What is seen in the image below?

Answer 3

• accessory nipple
• anomaly of development

Question 4

Athelia:

Answer 4

• no nipple and areola complex
• anomaly of development

Question 5

Amastia

Answer 5

• no breast except NAC
• anomaly of development

Question 6

What is seen below??

Answer 6

• tubular (juvenile breasts)

Question 7

Breast Location:

Answer 7

• lies on pectoralis major
• 2nd - 6th rib
• laterally related to serratus
  anterior
• inferiorly overlies upper border of
  rectus abdominis and laterally
  external oblique
• the upper and outer breast
  extends as the axillary tail into the
  axilla
• nipple and areola in mid-clavicular
  line at level of 4th ICL

Question 8

Topographical Anatomy:

Answer 8

insert diagram

Question 9

What separates the back of the breast from underlying pectoral fascia?

Answer 9

• a variable thickness of fat
• in the retromammary space

Question 10

What attaches the breast to pectoral fascia?

Answer 10

• suspensory ligaments
• extend from the breast dermis to
  the fascia

Question 11

Topographical Anatomy:

Answer 11

insert diagram

Question 12

What type of glands are contained within the nipple and areola?

Answer 12

Sweat and sebacious glands with antimicrobial properties

Question 13

The areola pigment becomes darker with

Answer 13

puberty

Question 14

Nipple size?

Answer 14

7mm for breast feeding

Question 15

Breast Surface Anatomy:

Answer 15

insert diagram

Question 16

Microscopic Anatomy of the Breast:

Answer 16

• glandular tissue to produce milk
• under hormonal control
• secretory structure = lobules with
  ducts
• ducts and lobules lined by
  columnar epithelium with
  myoepithelial cells in the
  basement membrane

Question 17

Microscopic Anatomy:

Answer 17

insert diagram

Question 18

Lactiferous ducts converge to the nipple forming the

Answer 18

lactiferous sinus

Question 19

Microscopic Anatomy: How many lobules per breast?

Answer 19

15-20 lobules: lobular and tubulo-alveolar

Question 19

What is shown below?

Answer 19

lactiferous ducts and lactiferous sinus

insert diagram

Question 20

Hormonal Changes and Effect on Breast:
- pubertal
- menstrual
- lactational
- post-menopausal

Answer 20

• breast development
• cyclical: glands are enlarging,
  sensitive, lumps
• lactational: more lobules
• involution: more fat than glandular
  tissue = fatty
  replacement

**listen to this slide

Question 21

Lactational Changes to the Breast:

Answer 21

• more lobules since middle of
  pregnancy onwards
• as a consequence toward the end
  of pregnancy milk lactation can
  occur
• elaborate duct system

Question 22

Arterial Supply to the Breast:

Answer 22

• Axillary Artery:
  
  • thoracodorsal
  • thoraco-acromial
  • lateral thoracic
• Internal Mammary Perforators
  provide 60% of supply to the breast

Question 23

Arterial Supply to the Breast:

Answer 23

insert diagram

Question 24

Arterial Supply to the Breast:

Answer 24

insert diagram *find extra

Question 25

Venous Drainage of the Breast:

Answer 25

- Superficial: - anterior surface of fascia draining NAC venous plexus - Deep: - into the axillary vein via the internal thoracic vein and perforating intercostal veins

Question 26

Venous Drainage of the Breast:

Answer 26

insert diagram

Question 27

Lymph flow:

Answer 27

insert diagram

Question 28

Lymphatic Drainage of the Breast:

Answer 28

- Superficial: - areola - subareola - Deep: - deep to subareolar - drain posteriorly and laterally to axillary nodes

Question 29

Lymphatic Drainage of the Breast:

Answer 29

insert diagram

Question 30

Where does the axillary artery arise from?

Answer 30

the subclavian artery which arises from the aortic arch

Question 31

What is shown below?

Answer 31

Lymphoedema due to removal of all nodes or several nodes -> lymph fluid blocks up

Question 32

Lymph Node Drainage of the Breast:

Answer 32

insert slide

Question 33

Lymphatic Drainage of the Breast to the Opposite Side:

Answer 33

***look

Question 34

Lymph Node Drainage

Answer 34

insert diagram

Question 35

Axillary Lymph Nodes:

Answer 35

insert diagram

Question 36

Which type of node is biopsied to check for metastasis of breast cancer?

Answer 36

sentinel nodes first node in chain

Question 37

Sensory Innervation to the Breast(3):

Answer 37

- lower cervical plexus - lateral cutaneous branch of T4 supplies the nipple - long thoracic nerve - intercostal 2nd-6th segmental branches

Question 38

Sensory and Autonomic Innervation to the Breast:

Answer 38

intercostal 2nd-6th segmental branches

Question 39

Innervation of the Breast:

Answer 39

insert diagram

Question 40

What are the functional units of the breast?

Answer 40

secretory lobules and ducts

Question 41

Breast: Lymph Drainage Direction:

Answer 41

upwards