Lecture 6 Gross Anatomy-Gervasi-Pectoral Region, Axilla, Brachial Plexus

What is a breast?

Modified sweat gland lying in the superficial fascia and overlying pectoralis major and separated from pectoralis by deep fascia

What determines the size of a breast?

Amount of fat surrounding the glandular tissue

How do breasts extend to the axilla?

Axillary tails

How are lobules drained in breasts?

Lactiferous ducts that open at the nipple

What suspensory ligaments attach breasts to the skin?

Cooper’s ligaments

Where do breasts receive blood supply from?

Internal thoracic, lateral thoracic, thoracoacromial, and intercostal arteries

Where is there lymphatic drainage in breasts?

Axillary, parasternal, abdominal and opposite breast associated lymph nodes

What are intrinsic muscles of the thoracic cage?

Considered to be true muscles of the thoracic wall. They alter the position of the ribs and sternum affecting thoracic volume

What are extrinsic muscles of the thoracic cage?

Muscles attached to and or covering the thoracic cage, and are primarily involved in serving other regions

Deltoid is innervated by?

Axillary nerve, C5 and C6

What are the medial attachments for pectoralis major?

Clavicle (clavicular head), sternum, and sixth costal cartilage (sternocostal head)

What is the lateral attachment for pectoralis major?

Lateral edge of intertubercular sulcus of humerus

What innervates pectoralis major?

Lateral and medial pectoral nerve

Lateral pectoral nerve innervates what parts of pectoralis major?

Both heads

The lateral pectoral nerve comes from?

The lateral cord of the brachial plexus

What is the spinal nerves associated with lateral pectoral nerve?

C5 C6 C7

Medial pectoral nerve innervates what part of pectoralis major?

Sternocostal head

The medial pectoral nerve comes from?

Medial cord of brachial plexus

What are the spinal levels associated with medial pectoral nerve?

C8 T1

What are the actions of pectoralis major?

Adduction, medial rotation, and shoulder flexion

Pectoralis minor is a landmark for?

Parts of the axillary artery

What are the medial attachments of pectoralis minor?

Ribs 3 4 and 5

What are the lateral attachments for pectoralis minor?

Coracoid process of scapula

What innervates pectoralis minor?

Medial pectoral nerve (C8 T1) from medial cord of brachial plexus

Actions of pectoralis minor?

Depresses scapula

Medial attachments for subclavius?

First rib and manubrium of sternum

Lateral attachments for subclavius?

Clavicle

Innervation of subclavius?

Nerve to subclavius (C5 and C6) from upper trunk of brachialplexus

Actions of subclavius?

Stabilization of clavicle and sternoclavicular joint, protection for subclavian vessels and brachial plexus in event of fractured clavicle

Anterior attachments for serratus anterior?

Ribs 1-8 or 9

Posterior attachments for serratus anterior?

Anterior side of medial border of scapula

Innervation of serratus anterior?

Long thoracic nerve (C5 C6 C7) from roots of brachial plexus

Actions of serratus anterior

Protraction of scapula, secures scapula to thoracic cage

Inability to properly contract scapula is called?

Scapular winging

Subclavian artery is a direct branch of?

Brachiocephalic artery or arch of aorta

Subclavian artery is deep to?

Scalenus anterior muscle

Subclavian artery continues as?

Axillary artery at lateral border of rib 1

What are the major branches of subclavian artery?

1. Vertebral

2. Thyrocervical trunk

3. Internal thoracic

4. Costocervical trunk

The vertebral artery ascends?

Cervical spine via transverse foramina to form vertebrobasilar system with cranium

What are the three branches of thyrocervical trunk?

1. Inferior thyroid

2. Suprascapular

3. Transverse cervical

Internal thoracic artery descends anteromedially posterior to?

Sternal end of clavicle

Costocervical trunk artery provides blood supply to?

Upper intercostal spaces and deep posterior neck

Axillary artery begins at?

Lateral border of rib 1

How many parts of axillary artery are there?

3

What is part 1 of axillary artery?

Lateral border of rib 1 to medial border of pectoralis minor

What is the major branch of part 1 of axillary artery? (Part one has one branch)

Superior thoracic

What is part 2 of axillary artery?

Deep to pectoralis minor

What are the major branches of part 2 of the axillary artery? (Part 2 has 2 branches)

Thoraco-acromial trunk and lateral thoracic

What is part three of the axillary artery?

Lateral border of pectoralis minor to inferior border of teres major tendon

What are the major branches of part 3 of axillary artery? (Part three has 3 branches)

Posterior circumflex humeral

Anterior circumflex humeral

Subscapular

Superior thoracic artery runs?

Along superior border of pectoralis minor, passing between pec minor and pec major to thoracic wall

Thoraco-acromial trunk curls?

Around superomedial border of pec minor

Lateral thoracic artery descends along?

Axillary border of pec minor

Lateral thoracic artery supplies?

Lateral aspect of the breast

Posterior circumflex humeral artery is a direct branch of?

Axillary artery

Posterior circumflex humeral artery passes posterior to?

Surgical neck of humerus

Posterior circumflex humeral artery supplies?

Deltoid and teres major muscles

Anterior circumflex humeral artery encircles?

Surgical neck of humerus forming an anastomosis with posterior circumflex humeral artery

What are the major branches of subscapular artery?

Circumflex scapular

Thoracodorsal

Brachial artery begins at?

Inferior border of tendon of teres major

What are major branches of brachial artery?

Profunda brachii

Superior and inferior ulnar collateral

Ulnar

Radial

Profunda brachii artery accompanies?

Radial nerve along radial groove of humerus and contributes to anastomosis at elbow

What is a branch of profunda brachii?

Radial collateral

Cephalic vein is a lateral superficial vein of upper limb and traverses?

Deltopectoral triangle and passes deep to enter axillary vein

Cephalic vein originates from?

Lateral aspect of dorsal venous arch of hand

Axillary vein is located?

Anteromedially to axillary artery

Axillary vein is formed by the union of?

Brachial vein and basilic vein at inferior border of teres major

Subclavian vein travels with?

Artery of same name

Axillary nerve is a terminal branch of?

Posterior BP cord

Axillary nerve passes?

Posteriorly through suprascapular and spinoglenoid notches

Axillary nerve supplies?

Deltoid and teres minor

What are the spinal levels of lateral pectoral nerve?

C5 C6 C7

Lateral pectoral nerve supplies?

Both heads of pectoralis major

Lateral pectoral nerve is from?

The lateral cord of brachial plexus

What are the spinal levels of medial pectoral nerve?

C8 T1

Medial pectoral nerve supplies?

Pectoralis minor and sternocostal head of pec major

Medial pectoral nerve comes from?

Medial cords of brachial plexus

Sometimes medial and lateral pectoral nerves are joined in a bridge over axillary artery called?

Ansa pectoralis

What are the spinal levels of long thoracic nerve?

C5 C6 C7

Long thoracic nerve comes from?

Roots of brachial plexus

Long thoracic nerve supplies?

Serratus anterior

Nerve to subclavius has what spinal levels?

C5 C6

Nerve to subclavius supplies?

Subclavius

Nerve to subclavius comes from?

Superior trunk of brachial plexus

In the axilla, acromial end of clavicle rises higher than?

The acromion

Infraclavicular fossa overlies the?

Deltopectoral triangle with access to cephalic vein

Posterior axillary fold consists of?

Latissimus dorsi

Anterior axillary fold consists of?

Pec major

What is in the apex border of axilla?

Bounded anteriorly by clavicle, posteriorly by superior border of scapula, medially by rib 1

What is the floor border of the axilla?

Axillary fascia and skin

What makes up the anterior wall of the axilla border?

Pec major and minor

What forms the posterior wall of axilla?

Latissimus dorsi, teres major and subscapularis

What forms the medial wall of the axilla?

Serratus anterior and ribs

What forms lateral wall of axilla?

Meeting point of anterior and posterior folds at intertubercular sulcus of humerus

How many roots are in the brachial plexus?

5

What are the roots of the brachial plexus?

Anterior primary rami of C5-T1

What are the branches of the roots of the brachial plexus?

Dorsal scapular nerve (from C4-C5 to rhomboids)

Long thoracic nerve (from C5-C7 to serratus anterior)

How many trunks are in the brachial plexus?

3

What are the three trunks of the brachial plexus?

Upper (C5-6)

Middle (C7)

Lower (C8-T1)

What are the branches of the trunks of the brachial plexus?

Suprascapular nerve (C4-6 from upper trunk) (supra and infraspinatus)

Nerve to subclavius (C5-6) from upper