gross anatomy

It is the junction b/w the head, thorax, and upper limb, and many nerves and vessels pass through it, including all the blood supply of the arm, forearm, adn hand

In the neck, forming from the C3-T2 vertebral levels; therefore, the nerve and blood supply to the upper limb come through the neck

• a. superior border fo the trapezius m.
• b. clavicle
• c. sternocleidomastodi m.- sternum, clavicle, mastoid
• d. investing layer of deep cervical fascia
• e. prevertebral fascia

• attach: sternum, clavicle, mastoid
• movement: pulls head anteriorly (when using both sides), rotates and tilts head when acting alone, provides imp. proctection for the carotid a. and internal jugualr v.
• supply: CN XI (same nerve as trapezius b/c when develop together and split

holds the clavicle agains the ribcage, and it provides a proective buffer if the clavicle is fractured (to help protect subclavian v. and a.

splenius, semispinalis capitis, levator scapulae, and the scalene mm.

• There are 3 (anterior, middle, posterior)
• attach: transverse processes of C2-C7 vert to the 1st or 2nd rib
• movement: when contract bilaterally, thery raise the first two ribs (e.g. heavy breathing), unilaterally they flex the neck to one side

• It is the gap b/w the anterior and middle scalene mm.
• The subclavian artery adn teh brachial plexus (blood and nerve supply to upper limb) pass this gap

• external jugular v.
• subcalvian v.
• subclavian a.
• thyrocervical trunk(a short branch off the first part of subclavin a.)- two branches
• -transverse cervical a.
• -suprascapular a.

placement: crosses sternoclavmas m and through deep cervical fascia and omohyoid fascia to empty into the subclavian v.

• placement: passes in front of the scalenus anterior m.
• supply: recieves blood from entire upper limb

• placement: emerges from behind the scalenus anterior m.
• supply: upper limb

• Two branches
• Transversecerical a.: crosses the root of the neck and typically gives a superficail branch (this supplies trap m.) adn the deep branch (the dorsal scapular a.) which passes deep ot the levator sapulae and rhomboid mm. to supply them
• Suprascapular a.: lies just deep to the clavicle, passing laterally then curving over the scapula to supply muscles on the posterior suface of scapula.

It is the nerves and vessels in the axilla are surrounded by a very loose fascia

• It is a continuation of the subclavian a., once passes out the cervical lateral region and into the axilla the name changes
• location of change: under the clavicle at the lateral border of the 1st rib

• The axillary a. becomes the branchial a. when exits the axilla and enters the arm
• location: emerges from beneath the inferior border of the teres major m.

• It is a branch of the first part of the axillary a.
• location: a small branch to teh upper thorax
• supply: 1st and 2nd intercostal spaces

• Part of the second part of the axillary a.
• location: a short trunk that pierces teh clavipectoral fascia and radiats into clavicular, acromial, deltoid, and pectoral branches

• location: descends along the lateral border of pectoralis major
• supply: pectoralis mm., the axillary lymph nodes, lateral part of the breast
• origin: usually branches directly from 2nd part of axillary a., but may branch from thoracacromial trunk

Usually much larger in women

• Part of third branch of ax a.
• location: wraps around surgical neck of humerus
• supply: lateral part of the shoulder

• location: branches with the anterior humeral a. , also runs with the axillary n. through the posterior wall of the axilla via the quadrangular space
• supply: deltoid, teres major and minor, long head of triceps brachii

• Part of the third branch of the ax a., the largest and most imp.
• location: desends on the thoracic wall along the lateral border of subscapularis and splits into the
• circumflex scapular a.: supplies the lateral parts of muscles on the posterior scapula
• thoracodorsal a.: supplies the inferior lateral portions of latissimus dorsi

allows alternates routes of blood flow, via anastomes (communications b/w arteries), in case blood flow is blocked through a main artery

The joining of two branches: brachial and basilic vv., which recieve blood in the upper limb.

The ax v. becomes the subclavian v. at the lateral borde of teh 1st rib adn empties into the brachiocephalic v. en route to the superior vena cava and heart

recieves blood from the arm and shoudler and joins the axilllary v. just distal to the transition form axillary to subclavian v.

fibrous tissue, supports the fat and glandular tissue and attach it to the dermis of the overlying skin

carries the milk to its opening at the nipple

where milk accumulates before beig expressed, it is a widen of the lactiferous ducts beneath the areola

• lateral thoracic and thoracoacromial aa.
• anterior intercostal branches of the internal thoracic a.
• posterior intercostal aa.

primarily the axillary v. (via lateral mammary and lateral thoracic vv.)

• lymph drains to the axillary lymph nodes (directly and via the pectoral, interpectoral, deltopectoal, supraclavicular adn inferior deep cervical nodes.
• NOTE: some of the lymph from the medial portion of the breast drains to parasternal nodes (or the opposite breast)