195b - Breast Development, Pregnancy, Lactation

Question 1

Which arteries supply the breast?

Answer 1

• Internal mammary artery
• Lateral thoracic artery

Question 2

Which arteries are circled in red?

Answer 2

Internal mammary arteries

Question 3

Which patients should recieve a screening mammogram?

Which patients should recieve a diagnostic mammogram?

Answer 3

• Screening
  
  • Anyone without any symptoms/lumps/concerns
• Diagnostic
  
  • Anyone with symptoms: Pain, lump, discharge, nipple retraction, skin changes
  • Anyone with abnormal/inconclusive findings from a screening mammogram

Question 4

How do estrogen and progeterone affect breast tissue during the menstrual cycle?

Answer 4

• Estrogen -> enlargement of breast ducts
• Progesterone -> growth of breast lobules

Question 5

If a concerning breast nodule is found on mammogram or ultrasound, what is the next step in management?

Answer 5

Core needle biopsy = most common

• Excisional biopsy only if discordant core biopsy results, or core biopsy inaccessible
• FNA is not recommended

Question 6

How does suckling affect breast milk secretion?

Answer 6

Not just a negative pressure response!

• -> Increased prolactin
  
  • -> initiation and maintenence of milk production
• -> Stimulates paraventricular and supraoptic nucleus of the hypothalamus
  
  • -> Paraventricular -> increased oxytocin
  • -> more milk ejection

Question 7

When does breast development stop?

When does breast tissue finish maturing?

Answer 7

Development stops ~2 years after menarche

Maturation continues until age 30

Question 8

Which hormones are important for lactation?

Answer 8

• Prolactin -> milk production
• Oxytocin -> milk ejection

Keep the P’s together, keep the vowels together

• Progesterone, estrogen -> prevent lactation during pregnancy by interfering with prolactin binding to alveolar cells
  
  • Drops during delivery -> lactation

Question 9

Describe the characteristics of benign nipple discharge

Answer 9

• Bilateral
• Any color except bloody or clear
• Multiductal

Question 10

List 3 non-hormonal factors that are important for breast development in puberty

Answer 10

• Body fat
• Sleep
• Sunlight
  
  • Vitamin D is important for LH/FSH

Question 11

Which nerves supply the breast?

Answer 11

• 3rd-6th intercostal supply most of the breast
  
  • Lateral and cutaneous branches
• Supraclavicular nerve supplies skin of the opper portion
  
  • Anterior cutaneous branches
• Intercostobrachial nerve supplies the medial aspect of the upper arm
  
  • Lateral cutaneous branch of the 2nd intercostal nerve

Question 12

How does gaining or losing weight affect breast density?

Answer 12

It doesn’t!

(Even change in body composition/fat mass do not affect breast density)

Question 13

Which veins drain the breast?

Answer 13

Venous drainage follows arteries, courses towards axilla

Circuous venosis = anastomotic circle under nipple/areola complex

Question 14

Which lymph nodes drain the breast?

Answer 14

• Axillary lymph nodes (most of the breast)
• Internal mammary lymph nodes (medail aspect of the breast)

Question 15

When in fetal development do the following occur?

• Breast development begins:
• Breast buds reduced to a single pair:
• Secondary buds develop:
• Areola begins to develop:
• Sweat, sebaceous, apocrine glands develop:

Answer 15

• Breast development begins: 5th week
• Breast buds reduced to a single pair: 7th week
• Secondary buds develop: 20th week
• Areola begins to develop: 20th week
• Sweat, sebaceous, apocrine glands develop: 2nd and 3rd trimester