Histology

Question 1

Where is the breast found?

Answer 1

Subcutaneously; in front of the deep fascia and pectoralis major muscle

Question 2

The secretory tissue of the breast is made up of what?

Answer 2

15-25 lobes

Question 3

Each breast lobe is split into smaller parts known as what?

Answer 3

Lobules

Question 4

What are lobules?

Answer 4

The glands which produce milk

Question 5

Each breast lobule is separated by what?

Answer 5

Adipose tissue

Question 6

The majority of the breast is composed of which type of tissue?

Answer 6

Stromal tissue

Question 7

Adjacent to secretory lobules is ? tissue, which in turn is surrounded by ? tissue?

Answer 7

Dense fibrous / adipose

Question 8

Most breast lesions are derived from which breast tissue?

Answer 8

Epithelial

Question 9

Where do the suspensory ligaments connect to and from?

Answer 9

Deep fascia overlying the anterior chest wall muscles to the dermis of the skin

Question 10

What are the suspensor ligaments composed of?

Answer 10

Fibrous connective tissue

Question 11

What is the significance of suspensory ligaments being anchored to the dermis of the skin?

Answer 11

When something in the breast is enlarging, this pulls the ligaments and can cause a puckered appearance of the skin

Question 12

What is the basic functional secretory unit of the breast?

Answer 12

The terminal duct lobular unit

Question 13

What are the acini?

Answer 13

Terminal ductules

Question 14

In the non-lactating breast, the acini (terminal ductules) lead into where?

Answer 14

Intralobular collecting duct

Question 15

Where do the intralobular collecting ducts lead into?

Answer 15

Lactiferous duct

Question 16

How many lactiferous ducts are there per breast lobe?

Answer 16

One

Question 17

Where does the lactiferous duct lead to?

Answer 17

The nipple

Question 18

On its way to the nipple, the lactiferous duct passes through an expanded region known as what?

Answer 18

Lactiferous sinus

Question 19

There is huge proliferation of which ducts during pregnancy?

Answer 19

Terminal ductules (acini)

Question 20

What is the difference between the connective tissue surrounding the acini within a lobule compared with the connective tissue outwith the lobule? What is the significance of this?

Answer 20

It is looser - this is to allow rapid expansion of the acini in pregnancy

Question 21

Within the lobule, the secretory epithelial cells which line the acini can be which kinds?

Answer 21

Cuboidal - columnar

Question 22

As well as a layer of epithelium, what are the ductules and ducts of the breast also lined with?

Answer 22

Contractile myoepithelial cells

Question 23

Ductules and ducts are lined by epithelial cells, myoepithelial cells and then what?

Answer 23

Basal lamina/basement membrane

Question 24

Describe the epithelial lining of the lactiferous duct?

Answer 24

Begins as stratified cuboidal epithelium and turns to stratified squamous epithelium as it gets nearer the nipple

Question 25

What type of epithelium lines the nipple?

Answer 25

Keratinised stratified squamous

Question 26

What makes up the core of the nipple?

Answer 26

Dense irregular connective tissue and bundles of smooth muscle

Question 27

What other type of glands are present around the nipple and end directly on the surface of the skin?

Answer 27

Sebaceous glands

Question 28

What is the definition of a mammary gland?

Answer 28

All the milk secreting tissue leading to a single lactiferous duct

Question 29

Most changes occur in the breast during which phase of the menstrual cycle?

Answer 29

Luteal phase

Question 30

What 3 things happen to the breast during the luteal phase?

Answer 30

Epithelial cells increase in height, lumens of the ducts become enlarged, small amounts of secretions appear in the ducts

Question 31

What changes occur to the breast in the 1st trimester of pregnancy?

Answer 31

Elongation and branching of smaller ducts / proliferation of epithelial/myoepithelial cells

Question 32

What changes occur to the breast in the 2nd trimester of pregnancy?

Answer 32

Differentiation of secretory alveoli, plasma cells and lymphocytes infiltrate connective tissue

Question 33

What changes occur to the breast in the 3rd trimester of pregnancy?

Answer 33

Alveoli mature and extensive rough ER develops

Question 34

What happens to the amount of connective tissue and adipose tissue in the breast during pregnancy?

Answer 34

They decrease

Question 35

What are alveoli?

Answer 35

The basic components of a mature mammary gland

Question 36

What happens to the breast after menopause?

Answer 36

The secretory cells of the TDLU degenerate leaving only ducts. There are fewer fibroblasts and reduced collagen/elastic fibres

Question 37

During pregnancy, what stimulates the proliferation of secretory tissue?

Answer 37

Oestrogen and progesterone

Question 38

What are the 4 main components of human milk?

Answer 38

Water, protein, carbohydrate, lipid

Question 39

What is the main carbohydrate found in breast milk?

Answer 39

Lactose

Question 40

What are the proteins found in breast milk?

Answer 40

Lactalbumin and casein

Question 41

Small quantities of what other things are found in breast milk?

Answer 41

Ions, vitamins and IgA antibodies

Question 42

What component of breast milk is secreted via apocrine secretion?

Answer 42

Lipids

Question 43

Describe apocrine secretion of lipids?

Answer 43

Lipid droplets are secreted surrounded by membrane and carrying a small amount of cytoplasm with it

Question 44

What component of breast milk is secreted via merocrine secretion?

Answer 44

Proteins

Question 45

Where are milk proteins a) made? b) packaged?

Answer 45

A) rough ER, B) Golgi apparatus

Question 46

Describe merocrine secretion of proteins?

Answer 46

Secreted via vesicles which merge with the apical membrane to release their contents into the duct system