Breast Anatomy

Question 1

When do the mammary crests/milk lines appear on the foetus?

Answer 1

4th week

Question 2

What type of gland is the breast?

Answer 2

Exocrine gland.
Modified sweat gland.
Tubulo-acinar gland.

Question 3

How many breast lobes are on each breast?

Answer 3

15-25

Question 4

How many women see malignant changes in the breast?

Answer 4

1 in 10.

Question 5

What is the function of breasts?

Answer 5

Female - secondary sexual feature.

Male - present in rudimentary form

Neonates - source of nutrition

Question 6

What does the lactiferous duct become?

Answer 6

Closer to the nipple it dilates to become the lactiferous sinus.

Question 7

What determines breast size and shape?

Answer 7

Genetics
Diet
racial

Question 8

Which ribs do the breasts overlie?

Answer 8

2nd or 3rd rib - 6th rib. (costal cartilages)

Question 9

What are the lateral borders of the breasts

Answer 9

Medial - sternal edge.
Lateral - mid-axillary line

Axillary tail - extends up into the axillary fossa.

Question 10

Which muscles does the breast overlie?

Answer 10

• pectoralis major
• pectoralis minor
• serratus anterior

Question 11

Which glands produce milk?

Answer 11

Mammary glands.

Question 12

Which muscle does the nipple possess?

Answer 12

Smooth muscle fibres.

Question 13

Which glands are present in the areola?

Answer 13

Sebaceous glands - these enlarge during pregnancy.

Question 14

What do the sebaceous glands produce?

Answer 14

An oily substance

• it sterilises the breast
• it tells the neonate where the nipple is located

Question 15

What is in the mammary gland?

Answer 15

Lots of alveoli, drained by a SINGLE lactiferous duct

Question 16

What are the name of the suspensory ligaments?

Answer 16

Ligaments of Cooper. These often change in malignancy, giving the breast an altered appearance.

Question 17

Where do the suspensory ligaments attach to?

Answer 17

The pectorals fascia (flat sheet of connective tissue) - which overlies the pectoralis major muscle.

Question 18

What is the arterial supply to the breast?

Answer 18

Medial - internal thoracic/mammary artery.

Lateral - lateral thoracic and thoracoacromial arteries, lateral mammary branches, mammary branch

Question 19

Which lymph nodes drain the breast?

Answer 19

• axillary (75%), (lateral quadrants)
• parasternal (20%)
• posterior intercostal (5%)
• can also drain into opposite breast or directly to supraclavicular or inferior cervical nodes

Question 20

Where does the lymph from skin of the breast go?

Answer 20

• skin - axillary lymph nodes

- nipple and areola - subareolar lymphatic plexus

Question 21

What is the nerve supply fo the breast?

Answer 21

anterior and lateral cutaneous branches of the 4th to 6th intercostal nerves.

^ This contains sensory and autonomic nerves.

Question 22

Which hormones control milk production and secretion?

Answer 22

• oxytocin (posterior)
• prolactin (anterior)

from pituitary gland.

Question 23

Which Fascia does the breast lie on?

Answer 23

2/3rds lies on the pectoralis major fascia.

1/3rds lies on the serratus anterior fascia.

Question 24

What are the main features of the nipple?

Answer 24

• 4th intercostal space (variable)
• lactiferous ducts open into them
• connective tissue, elastic fibres and smooth muscle

Question 25

What are the main features of the areola?

Answer 25

- contains lots of sweat and sebaceous glands - enlarge/pigment during pregnancy and lactation - oily substance provides protective lubricant

Question 26

What causes erection of the nipple?

Answer 26

Contraction of the band of smooth muscle surrounding the nipple

Question 27

What are the 4 quadrants of the breast?

Answer 27

- superiomedial - inferiomedial - inferiolateral - superiolateral (+ axillary tail)

Question 28

What is the male breast anatomy?

Answer 28

Has small ducts but NO LOBULES OR ALVEOLI.

Question 29

What happens to male breasts during puberty?

Answer 29

2/3rds of males develop varying hyperplasia of the breasts

Question 30

What is an extra breast called?

Answer 30

Polymastia

Question 31

What is an extra nipple called?

Answer 31

Polythelia

Question 32

What causes an extra breast or nipple?

Answer 32

persistence of the breast one

Question 33

What is absence of the nipple called?

Answer 33

Athelia

Question 34

What is absence of the breast called?

Answer 34

Amastia

Question 35

What is the venous drainage of the breast?

Answer 35

Medial - internal thoracic vein | Lateral - axillary vein

Question 36

Where does the sympathetic nerve innervation for the breasts blood vessels come from?

Answer 36

The cervical sympathetic chain.

Question 37

What is the first draining lymph node in the breast?

Answer 37

The sentinel node - this is tested during pathology. If the node isn't involved, the tumour hasn't spread.

Question 38

What is the excretory part of the breast?

Answer 38

Duct system.

Question 39

What is the secretory part of the breast?

Answer 39

Acini.

Question 40

What type of cells surround the ducts and acini?

Answer 40

Epithelial and myoepithelial cells (they squeeze the secretion that's in the acini by contracting).

Question 41

What are the milk parts of the breast called?

Answer 41

Lobes, acini/alveoli, lactiferous ducts, lactiferous sinus.

Question 42

What happens to the breast during puberty?

Answer 42

Before - lactiferous ducts but no alveoli/acini. Puberty - branching of lactiferous ducts, alveoli, lipids and adipocytes.

Question 43

What happens to the breast post menopausal?

Answer 43

- Progressive atrophy of lobules and ducts | - fatty replacement of glandular tissue

Question 44

In histology, how can you tell the difference between the fat and acinar cells?

Answer 44

Both white: - fat - not lined by epithelium - acini - lined by epithelium, can also see the secretions in the acini.

Question 45

What is colostrum?

Answer 45

protein rich fluid available a few days after birth - maternal antibodies, laxatives and low fat.