Anterior sternal half of the
Manubrium and Sternum upto
sixth costal cartilages
Cartilages of all the true ribs,
Aponeurosis of the abdominal
By a bilaminar tendon into the
lateral lip of the bicipital
groove of the humerus
Medial and lateral pectoral
Flexion of the
Adduction of the
Medial rotation of
Clavicular part : flexion,
adduction, and medial
rotation of the
extension of the flexed
arm as in climbing.
It aids in deep
It arises from the upper margins and outer
surfaces of the third, fourth, and fifth ribs,
Inserted into the medial border and upper
surface of the coracoid process of the scapula.
Medial and lateral pectoral nerves
Protracts the scapula with serratus anterior
Depresses the shoulder with the rhomboids
and levator scapulae
The pectoralis minor muscle is covered by
the clavipectoral fascia.
The medial pectoral nerve pierces the
pectoralis minor .
Axillary artery is divided into three parts by
Encloses subclavius and Pectoralis
It is pierced by :
Lateral pectoral nerve.
Thoraco- acromial artery
Lymph nodes from pectoral
region to apical group of axillary
Serratus anterior Origin
Arises from ribs 1 to 8, to be inserted into
the medial border of the scapula.
• Medial border of the scapula between
the superior and inferior angles.
digitations to upper angle of
digitations to medial border on
costal surface upto the inferior angle.
• Lower 4 digitations to inferior angle of
Protraction of the scapula along with
• The fibres inserted on inferior angle
rotate scapula laterally and upwards in
overhead abduction with trapezius.
Assists in respiration.
long thoracic nerve(Nerve of Bell)
• Serratus anterior is called the
Boxer’s muscle since it is
responsible for pushing and
• Paralysis of this muscle results
in a "winged scapula" ,results
in protrusion of the scapula on
the affected side when the
patient is asked to push
against the wall with both
• Winged scapula occurs in
lateral thoracic nerve
The mammary gland or
Modified Sweat Gland
Lies in Superficial fascia of
A small extension known as
Axillary tail of Spence
pierces the axillary fascia
through a small foramen
called the Foramen Of
Langer and lies in the axilla.
From second to sixth rib
in midclavicular line.
From lateral border of
sternum to midaxillary
line along the fourth
The Base of the Mammary gland called
Mammary Bed rests upon the following
structures (from Superficial to deep)
(b)Deep Fascia (Pectoral Fascia)
(c)Muscles- Pectoralis Major, Serratus Anterior,
A Space deep to the base of the gland, lies
superficial to deep fascia, contains loose
areolar tissue, makes the gland freely
Lies in fourth intercostal space, has high nervous
innervation and openings of 15-20 lactiferous
Pigmented area at the base of nipple, contains
modified sebaceous glands which become
enlarged during pregnancy and lactation
forming Tubercles of Montgomery
• Forms Suspensory Ligaments of Cooper which
anchor gland to overlying skin and underlying deep
• Divide the gland into 15-20 lobes.
• They may become contracted from fibrosis around a
carcinoma and produce a characteristic pitting of
the skin of the breast (peau d orange)
(B) GLANDULAR TISSUE
• Consists of 15-20 lobes.
• Arranged in a radiating
manner around the areola.
• In lobes are alveoli which
• Alveoli lined by
myoepithelial cells under
• Each lobe has one lactiferous
• The lactiferous duct dilates
near its opening in the nipple
to form lactiferous sinus
which acts as reservoir of
Anterior or Pectoral group
receive lymph from upper half
of anterior wall trunk and from
major part of breast.
Posterior or Scapular group
receive lymph from posterior
wall of upper half of trunk and
from axillary tail of breast.
Lateral group receives lymph
from upper limb.
Central group receives lymph
from preceding groups and
drains into apical group.
Apical or infraclavicular
(subclavian) group lie deep to
clavipectoral fascia. They
receive lymph from the central
group, from upper part of
breast and from the thumb.
Lymphatic drainage of Breast
Superficial portion of the
breast drains into the
subareolar plexus Of
Deep portion of the
breast drains to the
All the lymphatic of the
breast converge into the
Lymphatic drainage of breast
The lateral quadrants drain into
the anterior axillary or pectoral
group of lymph nodes. (75%)
The medial quadrants drain by
internal thoracic group of nodes.
A few lymph vessels follow
posterior intercostals arteries
and drain into posterior
intercostals nodes. (5%)
Some vessels communicate with
lymph vessels of opposite
breast and with lymph vessels of
subperitoneal lymph plexuses)
Perforating branches of
the Internal thoracic
branches from the
Lateral thoracic artery
Twigs from the
Pectoral branch of the
• Venous drainage of the breast is mainly
accomplished by the axillary vein.
• The subclavian, intercostal, and internal
thoracic veins also aid in returning blood to
• 4th through 6th intercostal nerves
Mammography is a radiographic examination of the breast. This technique is
used for screening the breasts for benign and malignant tumours of the
Breast cancer occurs in upper lateral quadrant (about 60% cases) and forms a
palpable mass in later stages.
It enlarges, attaches to Cooper’s ligaments and produces shortening of
ligaments, causing depression or dimpling of overlying skin.
It may attach to and shorten lactiferous ducts and cause retraction of
Obstruction of superficial lymph vessels by cancer cells may produce
edema of skin giving rise to an orange skin appearance called Peau
The cancer can spread through veins to the vertebrae and brain because
the veins draining the breast communicate with the vertebral venous
Localized cancer is treated by simple mastectomy .
Localized cancer of breast with early metastasis of axillary
lymph nodes, radical mastectomy is done to remove the
primary tumor and the lymph vessels and nodes that drain the
area. These are removed
a large area of skin overlying the tumor and including the nipple,
all the breast tissue
the pectoralis major and associated fascia,
the pectoralis minor and associated fascia
,all the fat, fascia and lymph nodes in axilla
fascia covering upper part of rectus sheath,
the serratus anterior, the subscapularis and the latissimus dorsi
In modified radical mastectomy, the pectoral muscles are left
In a breast abscess an acute infection of the
mammary gland occurs in which pathogenic
bacteria gain entrance to the breast tissue
through a crack in the nipple.
The abscess is localized to a lobe which id
drained through a radial incision to avoid
damage to the radially arranged ducts.