Superficial muscles of the back: Arranged in two layers: First layer: Trapezius Latissimus dorsi Second layer: Levator scapulae Rhomboideus major and minor

1.Trapezius: Origin: Superior nuchal line of occipital bone ligamentum nuchae Spinous process and supraspinous ligaments of all thoracic vertebra

Insertion: Posterior border of the lateral one third of the clavicle Medial border of acromion and upper lip of the crest of spine of scapula Deltoid tubercle

Nerve supply: Spinal part of accessory nerve 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: lower six thoracic spines and supraspinous ligaments Spines and supraspinous ligaments of all lumbar and sacral vertebra Outer lip of iliac crest

Insertion: 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: Insertion: Nerve supply: Transverse process of upper four cervical vertebra Insertion: 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: Insertion: Spinous process of T2 to T5 Insertion: Dorsal aspect of medial border of scapula Nerve supply: Dorsal scapular nerve

5.Rhomboideus minor: Origin: Nerve supply: Dorsal scapular nerve Ligamentum nuchae 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

THE BREAST / MAMMARY GLAND: It is present in both sexes It is a modified sweat gland

Situation: Extent: Vertical: Horizontal: 1 It lies in the superficial fascia 2 3 Extent: 4 5 Vertical: Second to sixth rib Horizontal: Later border of sternum to the mid axillary line 6 Axillary tail of spence

Relations: Mammary bed Retro-mammary space Pectoral fascia Pectoralis major muscle Serratus anterior muscle External oblique muscle Mammary bed Retro-mammary space External oblique Serratus anaterior

Features in the skin: Nipple: Areola: 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:

Posterior intercostal vein Internal thoracic vein Venous Drainage: Internal vertebral venous plexus Azygous vein 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

Parasternal lymph nodes Drainage: Intercostal nodes Posterior group Parasternal lymph nodes Anterior group Central group Apical group

Second set: Those draining the overlying skin excluding areola and nipple Supraclavicular nodes Infraclavicular nodes Parasternal nodes Axillary nodes Sub diaphragmatic lymph nodes Subperitoneal lymph plexus Krukenberg’s tumour Hepatic nodes Drainage

Applied anatomy: The breast is the frequent site of carcinoma Peau d’ orange

PECTORAL REGION

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: Actions: Medial and lateral pectoral nerve 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: Insertion: Third to fifth ribs Medial border and upper surface of the coracoid process

Nerve supply: Action: Medial and lateral pectoral nerve Assisted by serratus anterior muscle protracts the scapula Along with levator scapulae and rhomboideus it depresses the shoulder

Subclavius: Origin: Insertion: Junction of first rib and its costal cartilage Insertion: Groove on the undersurface of the middle third of the clavicle

Nerve supply: Action: Nerve to subclavius 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: Insertion: Eight fleshy digitations from outer surface and upper border of upper eight ribs Insertion: Costal surface along the medial border of scapula

Nerve supply: Action: Long thoracic nerve Along with pectoralis minor protracts the scapula With upper and lower fibers of trapezius it rotates the scapula forward and upwards

AXILLA

AXILLA /ARMPIT: Situation: It is a pyramidal shaped space present between upper end of arm and lateral thoracic wall

1 3 5 6 4 2 Boundaries: 1. Apex 2. Base 3.Anterior wall 4. Posterior wall 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: Axillary artery and its branches Axillary vein and its tributaries Cords of brachial plexus and their branches, long thoracic and intercosto brachial nerve Axillary lymph nodes 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 Trunks C5 C6 C7 C8 T1 Upper trunk Middle trunk Lower trunk

Trunks Split to form Divisions! (in neck) Trunks Divisions Upper Middle Lower Anterior Posterior Anterior Posterior Anterior Posterior

Divisions Join to form Cords! (in axilla) Trunks Divisions Cords U M L A LATERAL CORD P A MEDIAL CORD P A POSTERIOR CORD P

Cords Give off Branches!! (in axilla) LATERAL PECTORAL NERVE LATERAL CORD MUSCULOCUTANEOUS LATERAL ROOT OF MEDIAN NERVE MEDIAL PECTORAL NERVE MEDIAL ROOT OF MEDIAN NERVE MEDIAL CUTANEOUS NERVE OF ARM MEDIAL CORD MEDIAL CUTANEOUS NERVE OF FOREARM ULNAR NERVE UPPER SUBSCAPULAR THORACODORSAL POSTERIOR CORD 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: Abduction and lateral rotation of the arm is lost Flexion and supination of the forearm is lost

Site of injury: Lower trunk of brachial plexus 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