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Gbotolorun, S.C.
Introduction
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Most superficial structure in ant thoracic
wall
Situated in subcut tissue overlying
pectoral ms
Well developed + accessory to
reproduction in females
Rudimentary and functionless in males
Size determined by the amt of fat
surrounding glandular tissue
Size and shape may result from genetic,
racial & dietary factors
EXTENT
Transversely
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from the lateral border of the sternum
to the midaxillary line
Vertically
 From
A
the 2nd to the 5th ribs
small part may extend along the
inferolateral edge of the pectoralis
major towards the axilla- axillary
tail of spence
2/3- rest on deep pectoral fascia
overlying the pectoralis major
• 1/3- rests on the fascia covering
serratus anterior ms
• Btw breast and deep pectoral
fascia -retromammary space (RS)
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•A
loose CT or potential space
• The space contains a small amt of
fat• Allows breast move over the
pectoral fascia
Mammary
gland attached firmly to
dermis of overlying skin by skin
ligaments – the suspensory ligament
of Cooper
fibrous condensations of the CT stroma
• Well developed in the superior part of the
gland
• Help support the lobules of the gland
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During
puberty breast increase in size
bcos of increased fat deposit and
glandular development
The areolae and nipples also enlarge
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The lactiferous ducts give rise to buds
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Each lobule is drained by a lactiferous
duct
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opens independently on the nipple
The ducts converge towards the nipple
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15 to 20 lobules of glandular tissue
spokes of a bicycle wheel
Deep to the areola each duct dilates –
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lactiferous sinus
A --Duct.
B --Lobule.
C --Ampulla.
D --Nipple.
E --Fat.
F --Pectoralis.
G --Chest Wall.
The areolar contains numerous
sebaceous glands that enlarge
during pregnancy
• They secrete an oily substance
that lubricates the areola and
nipple
• The breast are modified sweat
glands
• They have no special capsule or
sheath
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Conical/cylindrical prominences in
the centre of the areolae
Devoid of fat, hair and sweat glands
In young nulliparous woman usually
in 4th intercostal space
Position varies especially in the
multiparous woman
Not a reliable guide to the 4th
intercostal space
• Tips are fissured with the
lactiferous ducts
• Composed mostly of circularly
arranged smooth muscles
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Arterial supply
Internal thoracic artery
• Lateral thoracic artery
• Thoracoacromial artery
• Posterior intercostal arteries
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Venous return
axillary vein
• Internal thoracic vein
• Intercostal vein
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LYMPHATIC DRAINAGE
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Very important=role in metatasis of
cancer cells
Lymph from nipple, areola and lobule
of gland– subareolar lymphatic plexus
Most lymph > 75% especially from
lateral quadrants of breast→axillary
nodes through the pectoral nodes
Some drain directly to the axillary
nodes/deltopectoral/supraclavicular/
interpectoral/inferior deep cervical
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Remaining lymph particularly from medial
quadrants →parasternal nodes/opposite breast
Lymph from lower quadrants → inferior phrenic
(abdominal) nodes
Lymph from skin of breast →axillary/inferior
deep cervical/infraclavicular/parasternal nodes
of both sides
Lymph from axillary →infraclavicular and
supraclavicular→subclavian lymphatic trunk
Lymph from parasternal
nodes→bronchomediastinal trunk
 Anterior
and lateral cutaneous branches of
the 4th to 6th intercostal nerves
 Breast
quadrants
 Carcinoma of breast
 Mastectomy/radical mastectomy/current
practice lympectomy (tumor & surrounding
tissues)
 Gynecomastia
 Polymastia, polythelia and amastia