1. Anatomy and Development of Breast (Mammary Gland)
Dr. Sama ul Haque

2. Objectives Describe the gross structure of the breast.
Give its blood supply and lymphatic drainage.
Discuss the development of breast and its congenital anomalies.

3. Breast (Mammary Gland)
Modified Sweat Glands of the skin
Functional in females (Milk secretion)
Rudimentary and functionless in males
Shape: Hemispherical

4. Breast (Mammary Gland)
Extent: Vertical: 2nd to 6th rib
(Base of the breast)
Horizontal: Lateral margin of the sternum to the midaxillary
line
2/3rd of the breast lies in the superficial fascia (Pectoral fascia) lying on Pectoralis major
1/3rd of the breast lies in the superficial fascia lying on Serratus Anterior

5. Breast (Mammary Gland)
Nipple: Conical or Cylindrical prominence in
the center of Areola (Devoid of fat, hair & sweat gland)
Surface anatomy: 4th intercostal space lateral to midclavicular line!!!!
Areola: Circular pigmented area of the skin surrounding the base of the nipple, containing sebaceous glands
Axillary Tail : Small part of the breast extending (of Spence) to the axilla

6. Breast

7. Breast

8. Breast (Mammary Gland)
Retromammary Space: Space filled with loose connective tissue between breast and pectoral fascia
Each breast consists of 15 to 20 lobules
Lactiferous ducts from each lobule open on the summit of the nipple separately
Lactiferous duct possesses a dilated Ampulla (Lactiferous sinus) just before its termination

9. Breast (Mammary Gland)
Fibrous septa separates the lobes of the mammary gland
Suspensory ligaments (of Cooper):
Mammary gland is firmly attached to the dermis of the skin by these fibrous septa forming suspensory ligaments

10. Breast

11. Arterial Supply of the Breast
Perforating branches (Internal thoracic artery)
Lateral thoracic artery (Axillary artery)
Thoracoacromial artery (Axillary artery)
Intercostal arteries

12. Arterial Supply of the Breast

13. Venous Drainage of the Breast

14. Nerve supply
Anterior and lateral cutaneous branches of the 4th – 6th intercostal nerves

15. Quadrants of the Breast

16. Lymphatic Drainage of the Breast
Lateral quadrants: Anterior Axillary or Pectoral Nodes
Medial quadrants: Internal thoracic group of Nodes (Parasternal)
Few lymph vessels drains into Posterior intercostal Nodes

17. Lymphatic Drainage of the Breast
Inferior quadrants: May drain into abdominal lymph Nodes
Some lymphatic vessels communicate with the lymphatic vessels of the opposite breast

18. Lymph Drainage of Breast

21. Comparison of active & inactive phase

22. Changes in mammary gland

24. Development of the Breast
Modified Sweat glands
First appear as bilateral bands of thickened epidermis called the mammary lines (mammary ridges)
In the 7th week these lines extends on each side of the body from Forelimb to the region of Hindlimb

25. Development of the Breast
Major part of each mammary lines disappears shortly
Small portion of the mammary lines in the thoracic region persists & penetrates the underlying mesenchyme
Here it forms 16 to 24 sprouts which in turn give rise to small solid buds

26. Development of the Breast
By the end of prenatal life, the epithelial sprouts canalize and form lactiferous ducts
Initially lactiferous ducts open into a small epithelial pit which shortly after birth transformed into nipple
At birth lactiferous ducts are devoid of alveoli
At puberty alveoli and excretory ducts form due to hormonal changes

28. Development Anomalies of the Breast
Polythelia (Accessary Nipples)
Accessary nipples have formed due to the persistence of fragments of the mammary line
May develop anywhere along the mammary line but usually appear in the axillary region

29. Development Anomalies of the Breast
Polymastia (Supernumerary breasts)
Occurs when a remnant of the mammary line develops into a complete breast
Inverted Nipple
Lactiferous ducts open in the original epithelial pit that has failed to evert.

30. Development Anomalies of the Breast

31. Development Anomaly of the Breast

33. Gynecomastia Enlargement of breasts in males Causes
May be at puberty (Usually regresses)
Drugs side effects
Prostatic cancer therapy
Hormonal imbalance

34. Thank you