anatomy and development of breast (mammary gland) dr. sama ul haque
TRANSCRIPT
Anatomy and Development of
Breast (Mammary Gland)
Dr. Sama ul Haque
Objectives
Describe the gross structure of the breast.
Give its blood supply and lymphatic drainage.
Discuss the development of breast and its congenital anomalies.
Breast (Mammary Gland)
Modified Sweat Glands of the skin
Functional in females (Milk secretion)
Rudimentary and functionless in males
Shape: Hemispherical
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
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
Breast
Breast
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
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
Breast
Arterial Supply of the Breast
Perforating branches (Internal thoracic artery)
Lateral thoracic artery (Axillary artery)
Thoracoacromial artery (Axillary artery)
Intercostal arteries
Arterial Supply of the Breast
Venous Drainage of the Breast
Nerve supply
• Anterior and lateral cutaneous branches of the 4th – 6th intercostal nerves
Quadrants of the Breast
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
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
Lymph Drainage of Breast
Comparison of active & inactive phase
Changes in
mammary gland
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
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
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
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
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.
Development Anomalies of
the Breast
Development Anomaly of the Breast
Gynecomastia
Enlargement of breasts in males
Causes May be at puberty (Usually regresses) Drugs side effects Prostatic cancer therapy Hormonal imbalance
Thank you