9: Lactation & The Breast

Question 1

What is mammary tissue in non-pregnant, non-lactating women?

Answer 1

Small part of breast tissue

Question 2

What is the mammary gland made up of?

Answer 2

15-20 lobulated masses of tissues

Question 3

What connects the lobes of the mammary gland?

Answer 3

Fibrous tissue and adipose tissue

Question 4

What is each lobe of the mammary glands made up of? (4 things)

Answer 4

1. Lobules of alveoli (site of milk production)
2. Blood vessels
3. Lactiferous ducts
4. Myoepithelial cells (SMC surrounding alveoli)

Question 5

What are the constituents of breast milk? (5 things)

Answer 5

1. Water
2. Lactose
3. Fat
4. Protein
5. Minerals + Vitamins

Question 6

How is mammary tissue developed at puberty? (mammogenesis) (2 steps)

Answer 6

1. Oestrogen causes ducts to sprout & branch → ends form masses of cells
2. Masses of cells become alveoli

Question 7

How do the mammary glands develop during pregnancy?

Answer 7

Increased progesterone / oestrogen ratio → favours alveoli development

But NO secretion

Question 8

How do the mammary glands develop after giving birth?

Answer 8

Progesterone levels decrease → alveolar cells responsive to prolactin (secreted from ant. pituitary)

Question 9

What does suckling do to prolactin secretion?

Answer 9

Initiates and maintains prolactin secretion

via Neuro-endocrine reflex:

• Impulse goes to hypothalamus
  
  • Decreases dopamine secretion
  • Decreases vaso-active intestinal peptide secretion

This increases prolactin secretion

Question 10

How is milk “let down”?

Answer 10

Suckling → reflex promotes milk “let down”:

• Increased oxytocin secretion → contracts myoepithelial cells → ejects milk from breast

Question 11

How is lactation stopped?

Answer 11

Suckling stops → decreased prolactin → less milk production

Question 12

Why can’t lactating mothers take certain drugs?

Answer 12

Because drugs go into milk

Example of these drugs: WARFARIN

Question 13

What are the types of breast cancer? (2 types)

Answer 13

1. Ductal Carcinomas In Situ
2. Invasive Carcinomas

Question 14

How are Ductal Carcinomas In Situ limited?

Answer 14

By BM supporting epithelium → stops tumour invading adjacent tissue

Question 15

What are risk factors of breast cancer? (6 things)

Answer 15

1. Gender
2. Age
3. Reproductive history
4. Obesity
5. Oestrogen exposure
6. Fatty diet

GAROOF

Question 16

What will give Ductal Carcinoma In Situ a good prognosis?

Answer 16

Mastectomy

Question 17

What is Paget’s disease?

Answer 17

When Ductal Carcinoma In Situ reaches nipple

Question 18

How does Invasive Carcinoma metastasise? (2 things)

Answer 18

1. Lymphatics
2. Blood

Question 19

Where does Invasive Carcinoma metastasise to?

Answer 19

1. Lymph nodes
2. Lungs
3. Liver
4. Brain

Question 20

What breast cancer patients have good outcomes?

Answer 20

1. Grade 1 breast cancer
2. Oestrogen Receptor (ER) Positive

Question 21

Why do Oestrogen Receptor (ER) Positive women have better outcomes?

Answer 21

They respond to Tamoxifen (ER antagonist) treatment

Question 22

What is associated with poor prognosis in breast cancer?

Answer 22

HER2 oncogene

Question 23

What are the 3 main breast cancer investigations?

Answer 23

1. Clinical
2. Radiographic imaging
3. Pathology

Question 24

What are the clinical ways of investigation breast cancer? (3 things)

Answer 24

1. History
2. Family history
3. Examination

Question 25

What are the radiographic imaging ways of investigation breast cancer? (2 things)

Answer 25

1. Mammography
2. US

Question 26

What are the aims of mammography?

Answer 26

To detect small impalpable / pre-invasive cancers

Question 27

What are the patholical ways of investigating breast cancer? (2 things)

Answer 27

1. Fine needle aspiration cytology
2. Core biopsy