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Superficial muscles of the back:
Arranged in two layers:
First layer:
1. Trapezius
2. Latissimus dorsi
Second layer:
1. Levator scapulae
2. Rhomboideus major and
minor
1.Trapezius:
Origin:
ᴥ Superior nuchal line of
occipital bone
ᴥ ligamentum nuchae
ᴥ Spinous process and
supraspinous ligaments
of all thoracic vertebra
Insertion:
ᴥ Posterior border of the
lateral one third of the
clavicle
ᴥ Medial border of
acromion and upper lip of
the crest of spine of
scapula
ᴥ Deltoid tubercle
Actions:
☻Upper and lower fibers – rotate the scapula
☻ Upper fibers along with levator scapulae
elevate the scapula
☻ Middle fibres of trapezius and the rhomboids
together retract the scapula
Nerve supply: Spinal part of accessory nerve
2.Latissimus dorsi:
Origin:
ᴥ lower six thoracic
spines and supraspinous
ligaments
ᴥ Spines and
supraspinous ligaments
of all lumbar and sacral
vertebra
ᴥ Outer lip of iliac crest
Insertion:
ᴥ Floor of intertubercular sulcus
of humerus
Nerve supply: Thoracodorsal
Actions:
☻Extension of shoulder joint
☻ In combination with the pectoralis major it is
powerfull adductor
3.Levator scapulae:
Origin:
ᴥ Transverse process of upper
four cervical vertebra
Insertion:
ᴥ Dorsal aspect of vertebral
border of scapula
Nerve supply:
Ventral rami of C3 and C4
Actions:
Elevates the scapula in combination with upper part of trapezius
4.Rhomboideus major:
Origin:
ᴥ Spinous process of T2 to T5
Insertion:
ᴥ Dorsal aspect of medial
border of scapula
Nerve supply: Dorsal scapular nerve
5.Rhomboideus minor:
Origin:
ᴥ Ligamentum nuchae
ᴥ Spinous process of C7 and T1
Nerve supply: Dorsal scapular nerve
Actions:
♥ Combined with middle fibres of tapezius retract the scapula
♥ With levator scapula depress the shoulder
THE BREAST / MAMMARY GLAND:

It is present in both sexes

It is a modified sweat gland
Situation:
1
It lies in the superficial fascia
2
3
Extent:
4
5
Vertical:
6
Second to sixth rib
Horizontal:
Later border of sternum
to the mid axillary line
Axillary tail
of spence
Relations:
☻
Pectoral fascia
☻
Pectoralis major muscle
☻
Serratus anterior muscle
☻
External oblique muscle
Retro-mammary
Mammary bed
space
External oblique
Serratus anaterior
Features in the skin:
Nipple:
It lies at the level of
fourth intercostal space
in nulliparous females
Areola:
It is a circular area of
skin around the base of
the nipple
Arterial supply:
Venous Drainage:
Azygous vein
Internal vertebral
venous plexus
Posterior
intercostal vein
Axillary vein
Internal
thoracic vein
Intracranial saggital &
transverse sinus
CIRCULUS VENOSUS
Clavicle and
humerus
Lymphatic drainage:
It consists of two sets:
◙ Those draining the parenchyma of the breast
including areola and nipple
◙Those draining the overlying skin excluding areola
and nipple
First set:
◙ Those draining the parenchyma of the breast including
areola and nipple:
From the parenchyma:
Subareolar plexus of sappey
Drainage:
Posterior group
Intercostal
nodes
Parasternal
lymph nodes
Anterior group
Central group
Apical group
Second set:
Those draining the overlying skin excluding areola and
nipple
Infraclavicular
nodes
Axillary nodes
Sub
diaphragmatic
lymph nodes
Supraclavicular
nodes
Parasternal
nodes
Subperitoneal
lymph plexus
Krukenberg’s tumour
Hepatic nodes
Drainage
Applied anatomy:
 The breast is the frequent site of carcinoma
 Peau d’ orange
Muscles of Pectoral Region:
It Includes:
┼
Pectoralis minor
┼
Subclavius
┼
Serratus anterior
┼
Pectoralis major
Pectoralis major:
Origin:
♣ Clavicular head
♣ Sternocostal head
Insertion:
Lateral lip of intertuberculus sulcus of humerus
Nerve supply:
Medial and lateral pectoral nerve
Actions:
♥ Medial rotation and adduction of the shoulder joint
♥ Clavicular head produces flexion of shoulder joint
♥ Sterno-costal head helps in extension to bring flexed
humerus to the side as in climbing
Pectoralis minor:
Origin:
Third to fifth ribs
Insertion:
Medial border and
upper surface of
the coracoid
process
Nerve supply:
Medial and lateral pectoral nerve
Action:
 Assisted by serratus anterior muscle protracts the
scapula
 Along with levator scapulae and rhomboideus it
depresses the shoulder
Subclavius:
Origin:
Junction of first rib and
its costal cartilage
Insertion:
Groove on the
undersurface of the
middle third of the
clavicle
Nerve supply:
Nerve to subclavius
Action:
Stabilise the calvicle during
the shoulder movements
Clavipectoral fascia
It is a strong sheet of
fascia which stretches
from the pectoralis minor
to clavicle
Structures piercing
the fascia:
 Cephalic vein
 Lymphatics
 Lateral pectoral nerve
 Thoraco-acromial vessels
Serratus anterior:
Origin:
Eight fleshy digitations
from outer surface and
upper border of upper
eight ribs
Insertion:
Costal surface
along the medial
border of scapula
Nerve supply:
Long thoracic nerve
Action:
Along with pectoralis minor
protracts the scapula
With upper and lower fibers
of trapezius it rotates the
scapula forward and upwards
AXILLA /ARMPIT:
Situation:
It is a pyramidal shaped
space present between
upper end of arm and
lateral thoracic wall
1
Boundaries:
1. Apex
3
2. Base
3.Anterior wall
4. Posterior wall
5
6
4
5. Medial wall
6. Lateral wall
2
1. APEX:
It is also called as cervico-axillary canal
2. Base:
Infront : Anterior axillary fold
Behind: Posterior axillary fold
3. Anterior wall
4. Posterior wall
5. Medial wall
6. Lateral wall
Contents:
1. Axillary artery and its branches
2. Axillary vein and its tributaries
3. Cords of brachial plexus and their branches, long
thoracic and intercosto brachial nerve
4. Axillary lymph nodes
5. Axilary fat and occasionally axillary tail of the
breast
Axillary artery:
 It is a continuation of third part of subclavian
artery at the outer border of first rib
Branches:
First part: Superior thoracic artery
Second part:
 Thoraco acromial artery
 Lateral thoracic artery
Third part:
 Subscapuar artery
 Anterior circumflex scapular artery
 Posterior circumflex artery
Quadrangular
space
Scapular anastomosis:
In each of subscapular, supraspinous and
infraspinous fossae
Suprascapular
Deep branch of transverse cervical arteries
With
Circumflex scapular artery
Over the Acromion Process:
Acromial branch of Suprascapular artery
Thoraco-acromial artery
With
Posterior circumflex humeral arteries
Brachial plexus:
♥ Muscles of upper limb receive innervation
from nerves of the brachial plexus
 Formation:
Lower four cervical nerves and the first thoracic
nerve (C5-8) and T1
Parts of Brachial Plexus:
It consists of
R = ROOTS (Ventral rami)
T = TRUNKS
D = DIVISIONS
C = CORDS
B = BRANCHES
Roots join to form Trunks! (in neck)
• Ventral Rami
•
•
•
•
•
C5
C6
C7
C8
T1
Trunks
Upper trunk
Middle trunk
Lower trunk
Trunks Split to form Divisions! (in neck)
• Trunks
Divisions
Anterior
• Upper
Posterior
Anterior
• Middle
• Lower
Posterior
Anterior
Posterior
Divisions Join to form Cords! (in axilla)
Trunks
U
Divisions
A
MEDIAL CORD
P
A
L
LATERAL CORD
P
A
M
Cords
P
POSTERIOR
CORD
Cords Give off Branches!! (in axilla)
LATERAL CORD
LATERAL PECTORAL NERVE
MUSCULOCUTANEOUS
LATERAL ROOT OF MEDIAN NERVE
MEDIAL PECTORAL NERVE
MEDIAL CORD
MEDIAL ROOT OF MEDIAN NERVE
MEDIAL CUTANEOUS NERVE OF ARM
MEDIAL CUTANEOUS NERVE OF FOREARM
ULNAR NERVE
UPPER SUBSCAPULAR
POSTERIOR
CORD
THORACODORSAL
LOWER SUBSCAPULAR
AXILLARY NERVE
RADIAL NERVE
APPLIED ANATOMY:
1. ERB’S PARALYSIS:
Site of injury: Upper Trunk of Brachial plexus
Cause of injury: Undue separation of the head from
shoulder
Nerves roots involved: C5 – C6
Muscles paralysed:
Biceps, Deltoid, Brachialis & Brachioradialis.
Partly supraspinatus, infraspinatus and supinator
Deformity: (Position of the limb)
Arm: Adducted and Medially rotated
Forearm: Extended and Pronated
The deformity is known as
Policeman’s tip hand or Porter’s tip paralysis
Disability:
1. Abduction and lateral rotation of the arm is lost
2. Flexion and supination of the forearm is lost
2. Klumke’s Paralysis:
Site of injury: Lower trunk of brachial plexus
Cause of injury: Undue abduction of arm
Nerves roots involved: T1 and partly C8
Muscles paralysed:
Intrinsic muscles of the hand (T1)
Ulnar flexors of the wrist and fingers (C8)
Deformity: (Position of hand)
Claw hand
3.Injury to the nerve to serratus anterior muscle:
Cause:
Sudden pressure on the shoulder from above
Carrying heavy loads on the shoulder
Deformity:
Winging of scapula
Disability:
Loss of pushing and punching movements
Arm cannot be raised beyond 90o