Mammary Gland

Question 1

What are the characteristics of the mammary gland?

Answer 1

It is a modified sweat gland
Accessory female reproductive organ

Question 2

What is the vertical extent of the mammary gland?

Answer 2

2nd to 6th rib in mid clavicular line

Question 3

What is the lateral extent of the mammary gland?

Answer 3

Lateral border of sternum to mid-axillary line along the 4th rib

Question 4

What is the mammary bed?

Answer 4

Base on which the gland rests formed by:
* Pectoralis major-medial 2/3rd
* Serratus anterior-lateral 1/3rd
* External oblique aponeurosis in infero-medial quadrant

Question 5

What is the retromammary space?

Answer 5

Loose connective tissue between the base of gland and the deep fascia covering mammary bed

Question 6

What is the axillary tail of Spence?

Answer 6

Tail-like projection enters the axilla

Question 7

What is the nipple?

Answer 7

Conical projection at the level of 4th intercostal space

Question 8

What is the structure of the nipple?

Answer 8

• Pierced by 15-20 lactiferous ducts
• Circularly & longitudinally disposed smooth muscles
• Rice nerve supply
• No subcutaneous fat or hair

Question 9

What is the areola?

Answer 9

Pigmented circular area around the base of the nipple

Question 10

What is the structure of the areola?

Answer 10

Modified sebaceous glands on the outer margin-tubercles of Montgomery-lubrication
Beneath the areola lactiferous ducts dilate to form lactiferous sinus before passing through the nipple
Lymphatic plexus of sappy- subareolar

Question 11

Define parenchyma

Answer 11

Parenchyma is the functional tissue of an organ as distinguished from the connective and supporting tissue.

Question 12

What are lobes in the parenchyma?

Answer 12

A lobe is a cluster of alveoli drained by a lactiferous duct (milk ducts, mammary ducts)

Question 13

Describe the lobes

Answer 13

Composed of glandular tissue compound: tubulo-alveolar arranged in lobes
15-20 pyramidal lobes
Lobes are arranged in radiating manner converge towards the areola

Question 14

What is the lactiferous sinus?

Answer 14

Slight dilatation of lactiferous duct beneath the areola.
Small amount of milk may accumulate here in active gland

Question 15

What are myoepithelial cells?

Answer 15

Found around the alveoli and ducts.
Their contraction facilitate passage of the milk from the alveoli

Question 16

What are the support structures of the breast tissue?

Answer 16

Stroma: Supporting framework of the gland
Ligaments of Cooper: Bands of fibrous, flexible connective tissue underlying the pectoral fascia
Fatty tissue

Question 17

Describe mammary glands in prepuberty

Answer 17

Presence of lactiferous ducts without alveoli

Question 18

Describe mammary glands at puberty

Answer 18

Ducts undergo branching
Forms solid masses which are precursors of alveoli

Question 19

Describe mammary glands during pregnancy and lactation

Answer 19

Proliferation & epithelial growth of ducts & lobules
Increase in the number of alveoli

Question 20

Which arteries supply the mammary glands?

Answer 20

Internal thoracic artery: Perforating branches
Axillary artery: Lateral thoracic, superior thoracic & thoraco-acromial branches
Posterior intercostal arteries: Lateral branches

Question 21

Which veins drain the mammary glands?

Answer 21

Veins follow the arteries and form the plexus circulous venosus under the areola
Superficial veins drain into internal thoracic vein
Deep veins drain into internal thoracic, axillary & posterior intercostal veins

Question 22

Describe the nerve supply of the mammary glands

Answer 22

Supplied by anterior and lateral cutaneous branches of 4th to 6th intercostal nerves
Convey sensory fibers to the skin
Autonomic fibers to smooth muscles

Note: These nerves do not control milk secretion. It is controlled by hormone prolactin

Question 23

Describe the deep lymphatic drainage of the mammary glands

Answer 23

Deep lymphatics: Drain the parenchyma including areola & nipple
75% drained by axillary lymph nodes – end mostly in anterior group close to the axillary tail of spence partly into posterior & apical groups
20% drained into parasternal group from both medial & lateral parts
5% drained into posterior intercostal nodes

Question 24

Describe the superficial lymphatic drainage of the mammary glands

Answer 24

Superficial lymphatics: Drain the overlying skin excluding areola & nipple
Outerpart: axillary nodes
Upper part: supraclavicular nodes
Inner part: parasternal nodes

Question 25

What is fibrocystic breast disease?

Answer 25

Benign condition
Often related to cyclic changes in glandular tissue
Occurs in 80% of women

Question 26

What are fibroadenomas?

Answer 26

Firm, painless, solitary, palpable mass
Benign neoplasms of glandular epithelium

Question 27

What is breast cancer?

Answer 27

Most common malignancy in women
Infiltrating ductal carcinoma is most common type
Involves the suspensory retinacula
Causes retraction of the ligaments and dimpling of the overlying skin

Question 28

What is peau d’orange?

Answer 28

Obstruction & invasion of subcutaneous lymphatics, stagnation of lymph and skin edema creating orange peel appearance

Question 29

Where are tumors generally palpated on breast tissue?

Answer 29

60% of palpable tumors are found in upper outer breast quadrant closest to the axilla including the axillary tail