This document provides an overview of the anatomy of the pectoral region. It describes the surface landmarks, superficial fascia containing cutaneous nerves, vessels and the platysma muscle. The breast composition and blood supply are explained. The muscles of the pectoral region including pectoralis major, pectoralis minor, subclavius, and serratus anterior are also detailed. Finally, the clavipectoral fascia enclosing the pectoralis minor is briefly outlined.

1. Pectoral Region
Dr.Heta Patel(PT)
Assistant Professor
ARIP
cHARUSAT

2. What to learn?
• Introduction
• Surface landmarks
• Superficial fascia
• Deep fascia
• Muscles of pectoral region

3. Introduction
• Location: Front of chest
• Essential consist of structure which connects the upper
limb to the anterolateral chest wall
• i.e. bones and muscles
• Additionally Mammary gland

4. Surface landmarks
• Clavicle
• Jugular notch
• Sternal angle
• Epigastria fossa
• Nipple

5. • Midclavicular
• Infraclavicular fossa
• Coracoid process
• Acromion
• Deltoid
• Midaxillary line

7. Superficial fascia
• Band
• Contains: moderate amount of fat, mammary
gland, fibrous septa
Contents
1) Cutaneous nerves
2) Cutaneous vessels
3) The platysma
4) The breast

8. Cutaneous Nerves
• Branches of the cervical plexus (C3, C4):(medial,
intermediate and lateral supraclavicular nerves)
• skin over the upper half of the deltoid and from the
clavicle down to the second rib.
• The anterior and lateral cutaneous branches of the second
to sixth intercostal nerves : skin below the level of the
second rib.
• The intercostobrachial nerve T2 : skin of the floor of the
axilla and the upper half of the medial side of the arm.

10. • Pulled away: The area supplied by spinal nerves
C3 and C4 directly meets the area supplied by
spinal nerves T2 and T3. This is because of the
fact that the intervening nerves (C5, C6, C7, C8
and T1) have been 'pulled away' to supply the
upper limb.

11. Cutaneous Vessels
• The cutaneous vessels are very small.
• The anterior cutaneous nerves are accompanied
by the perforating branches of the internal
thoracic artery.
• The second, third and fourth of these branches
are large in females for supplying the breast.
• The lateral cutaneous nerves are accompanied by
the lateral cutaneous branches of the posterior
intercostals arteries.

12. The Platysma
• Thin, broad sheet of subcutaneous muscle.
• Muscle of face
• Supplied by the facial nerve.
• When the angle of the mouth is pulled down, the muscle
contracts and wrinkles the skin of the neck.
• The platysma may protect the external jugular vein
(which underlies the muscle) from external pressure.

13. The Breast

14.  Modified sweat gland- modified apocrine gland
 Made up of 15–20 lobules of glandular tissue
embedded in fat.
 Fat accounts for its smooth contour and most of its
bulk.
 These lobules are separated by fibrous septa
running from the subcutaneous tissues to the
fascia of the chest wall (the ligaments of
Cooper/ Astley Cooper fibers/ suspensory
ligaments)
 Between the capsule and the fascia over pectoralis
major is the loose connective tissue of the
retromammary space.

15.  Each lobule drains by its lactiferous
duct on to the nipple, which is
surrounded by the pigmented areola.
 This area is lubricated by the areolar
glands of Montgomery
◦ large,
◦ modified sebaceous glands →may form
sebaceous cysts → may infected.

16. Surface anatomy

17. Naming the quadrants for the
purpose of describing a lump Or
1. Upper medial
quadrant
2. Upper lateral
quadrant
3. Lower medial
quadrant
4. Lower lateral
quadrant

18. Position & extent



2/3 rests on
pectoralis major,
1/3 on serratus
anterior,
while its lower
medial edge just
overlaps the upper
part of the rectus
sheath.

20. Cross section

22. Blood supply

23.  Axillary artery →
◦ Lateral thoracic (mainly)
◦ Acromiothoracic branches.
 Internal thoracic (internal mammary) artery
→perforating branches; these pierce the 1st – 4th
intercostal spaces, then traverse pectoralis major
to reach the breast along its medial edge. The 1st
& 2nd perforators are the largest of these
branches.
 Intercostal arteries → lateral perforating
branches- relatively unimportant source.

24. Venous drainage

25. Venous drainage
 Sub areolar venous plexus
 Posterior intercostal veins communicate
with internal vertebral venous plexus
veins - therefore cancers can spread to
vertebra- may cause back pain

26. Lymphatic drainage

28.  Follows the pathway of its blood supply
 along tributaries of the
1. axillary vessels → axillary lymph
nodes;
2. internal thoracic vessels → piercing
pectoralis major → to traverse each
intercostal space → to lymph nodes along
the internal mammary chain; these also
receive lymphatics penetrating along the
lateral perforating branches of the
intercostal vessels.

29.  A subareolar plexus of lymphatics
below the nipple (the plexus of
Sappey)
 75% → axillary
 15% → internal mammary
 Upper → can go to supraclavicular
 Lower 2 quadrants can go to
subdiapragmatic or abdominal nodes

31. Dermatomal supply

32. Development and structure
 Begins to develop as early as the 4th week as a
downgrowth from a thickened mammary ridge
(milk line) of ectoderm along a line from the
axilla to the inguinal region.
 Supernumerary nipples or even glands proper
may form at lower levels on this line.

33.  Lobule formation occurs only in the female
• breast & does so after puberty.
 Each lactiferous duct is connected to a tree- like system
of ducts and lobules, intermingled & enclosed by
connective tissue to form a lobe of the gland.

35.  The resting (non-lactating) breast, however
consists mostly of fibrous & fatty tissue;
variations in size are due to variations in fat
content, not glandular tissue which is very
sparse.

36.  During pregnancy alveoli bud off from the smaller ducts
& the organ usually enlarges significantly, & more so in
preparation for lactation.
 When lactation ceases there is involution of secretory
tissue.
 After menopause progressive atrophy of lobes & ducts
takes place.

37. The male breast
 Resembles the rudimentary female
breast
 has NO lobules or alveoli.
 The small nipple and areola lie over
the 4th intercostalspace.

38. Clinical anatomy
 Amastia (Absence of breast)
 Polymastia (Supernumerary breasts)
 Athelia (Absence of nipple)
 Polythelia (Supernumerary nipples)
 Gynaecomastia (in Klinefelter’s syndrome)
 Breast cancer
 Breast abscess

39. Amastia of right breast
Polymastia
Polythelia
Nipple retraction
Athelia
Gynaecomastia

40. • Radiological investigation : Mammography

41. MUSCLES OF THE PECRORAL
REGION
• 1. Pectoralis major
• 2. Pectoralis minor
• 3. subclavius
• 4. Serratus
anterior

42. Pectoralis major
Origin:
1. Clavicular head; from the front of the
medial third of the clavicle
2. Sternocostal head; from the anterior aspect
of the sternum and the upper six costal
cartilages
Insertion: Lateral lip of bicipital groove of the
humerus
Action: 1. Adduction and medial rotation of
the arm
2. Flexion of the arm (clavicular
portion)
Nerve supply
1. Lateral pectoral nerve, C5, 6, 7
2. Medial pectoral nerve, C8, T1

44. Pectoralis minor
Origin: 3rd , 4th and 5th ribs near
their cartilage.
Insertion: Medial aspect of
coracoid process of the scapula
Action:
• Depresses point of shoulder; if
the scapula is fixed, it elevates
the ribs of origin
• Nerve supply: medial pectoral
nerve, C8,T1

45. Subclavius muscle
• Origin: First costal cartilage
• Insertion: Lower surface of
clavicle (subclavius groove)
• Action: Depresses the clavicle and
steadies this bone during
movements of the shoulder girdle
• Nerve supply: Nerve to the
subclavius, from the roots of
brachial plexus C5,6

46. Serratus anterior muscle
• Origin: From the outer surface of
upper 8 ribs
• Insertion: costal aspect of medial
border and inferior angle of scapula
• Action:
• Draws the scapula forward around
the thoracic wall (protrusion); rotates
scapula
• Nerve supply: long thoracic nerve,
C5,6,7

47. Clavipectoral Fascia
• The clavipectoral fascia is a strong sheet of
connective tissue that is attached above to the
clavicle.
• Below, it splits to enclose the
pectoralis minor
then continues
muscle and
downward as
the suspensory ligament of the
axilla and joins the fascial floor of
the armpit.

48. THANK YOU