main action - descending part elevates; ascending part depresses; and middle part retracts scapula; descending and ascending parts act together to rotate glenoid cavity superiorly

innervation - dorsal scapular (C5) and cervical (C3, C4) nerves

main action - elevates scapula and tilts its glenoid cavity inferiorly by rotating scapula

 innervation - dorsal scapular (C4,C5)

main action - retract scapula and rotate it to depress glenoid cavity

innervation - medial pectoral nerve (C8, T1)

main action - stabilizes scapula by drawing it inferiorly and anteriorly against the thoracic wall

innervation - long thoracic nerve (C5, primarily C6 and C7)

main action - protracts scapula and holds it against thoracic wall; rotates scapula

innervation - nerve to subclavius (primarily C5, C6)

main action - anchors and depresses clavicle

innervation - lateral and medial pectoral nerves; clavicular head (C5, primarily C6), sternocostal head (primarily C7 and C8, T1)

main action - adducts and medially rotates humerus; draws scapula anteriorly and inferiorly. Acting alone, clavicular head flexes humerus and sternocostal head extendes it from the flexed position

innervation - thoracodorsal nerve (middle subscapular), (primarily C6 and C7, C8)

main action - extends, adducts, and medially rotates humerus; raises body toward arms during climbing

innervation - axillary nerve (primarily C5, C6)

main action - clavicular (anterior) part flexes and medially rotates arm; acromial (middle) part abducts arm; spinal (posterior) part extends and laterally rotates arm

innervation - suprascapular nerve (C4, primarily C5, C6)

main action - initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles

innervation - suprascapular nerve (primarily C5,C6)

main action - laterally rotate arm; help hold humeral head in glenoid cavity of scapula

innervation - axillary nerve (primarily C5,C6)

main action - laterally roate arm; help hold humeral head in glenoid cavity of scapula

innervation - lower subscapular nerve (C5, primarily C6)

main action - adducts and medially rotates arm

innervation - upper and lower subscapular nerves (C5, primarily C6, and C7)

main action - medially rotates and adducts arm; helps hold humeral head in glenoid cavity

innervation - musculocutaneous (C5, primarily C6)

main action - supinates forearm and, when it is supine, flexes forearm; short head resists dislocation of the shoulder

innervation - musculocutaneous nerve (C5, primarily C6, C7)

main action - helps flex and adduct arm; resists dislocation of the shoulder

innervation - radial nerve (C6, primarily C7 and C8)

main action - chief extensor of forearm; long head resists dislocation of humerus; especially important during abduction

It is a commonly occuring extension of gland that penetrates the deep fascia and enters the axilla, along the anterior axillary fold.

It is important to include this area during routine breast exams, and recognize the axillary tail as a normal tissue component rather than an abnormal finding

Anterior (pectoral) axillary nodes = Level 1 nodes

location - along lateral border of pectoralis minor

drainage area - anterolateral abdominal wall above umbilicus, including lateral aspect of breast

Central (deep) axillary nodes = Level 2 nodes

location - center of axilla, deep to pectoralis minor

drainage area - anterior, posterior, and lateral nodes

Apical (medial) axillary nodes = Level 3 nodes

location - apex of axilla, above upper medial border of pectoralis minor, medial to axillary vein

drainage area - the areas from anterior, posterior, lateral, central, and infraclavicular nodes

Apex - first rib, clavicle, and superior edge of subscapularis

base - concave skin, subcutaneous tissue, and axillary (deep fascia) extending from the arm to the thoracic wall

anterior wall - pec. major and minor

posterior wall - subscapularis, teres major, lat.dorsi

medial wall - thoracic wall and serratus anterior

lateral wall - intertubercular groove of humerus

1) axillary artery

2) axillary vein

3) brachial plexus

4) axillary lymph nodes

Formed by the deltoid, pec.major, and clavicle - pec. major and deltoid form the deltopectoral groove and then the muscles diverge superiorly to form the triangle with the clavicle

cephalic vein runs through it (remember cephalic vein was running through the deltopectoral groove)

coracobrachialis

biceps brachii

brachialis

*all of the anterior forearm muscles except flexor carpi ulnaris and the ulnar half of flexor digitorum profundus

*the 3 thenar muscles - abductor pollicis brevis, opponens policis, and flexor pollics brevis (all by recurrent branch of median nerve)

*lumbricals to digits to 2 and 3

flexor carpi ulnaris

ulnar half of flexor digitorum profundus

adductor pollicis

7 interossei (4 dorsal and 3 palmar)

lumbricals to digits 4,5

3 hypothenar muscles - abductor digiti minimi, flexor digiti minimi, and opponens digiti minimi (deep branch of the ulnar nerve)

Levator scapulae

rhomboid major and minor

Serratus anterior

*note it inserts on the anterior side of the muscle (exception), this makes the nerve vulnerable to damage

Supraspinatus

infraspinatus

Deltoid

teres minor

all posterior muscles of the arm and forearm

*extensors

*triceps

*brachioradialis

*supinator

*aconeus

*abductor pollicis longus

*primarily responsible for flexion and pronation

*flexors of shoulder and/or elbow - biceps, brachialis, and coracobrachialis

*biceps brachii is an exception to the pronation rule - it is the power supinator of the forearm

*motor nerve - musculocutaneous

*median nerve just passes thru and travels with brachial artery

*primarily extension and supination

*extensor of the shoulder and elbow - triceps and anconeus

*motor nerve - radial nerve

*deep brachial artery travels next to the radial nerve

*fracture of the midshaft of humerus - endangers radial nerve and deep brachial artery

*axillary nerve - it innervates deltoid and teres minor

*posterior circumflex humeral artery

*base - imaginary line that connects the medial epicondyle and lateral epicondyle of the humerus

*lateral wall - brachioradialis

*medial wall - pronator teres

*posterior wall (floor) - brachialis and supinator

*roof - brachial and antebrachial deep fascia

*terminal part of the brachial artery and the commencement of its terminal branches - radial and ulnar arteries; the brachial artery lies between the biceps tendon and the median nerve

*(deep) accompanying veins of the arteries

*biceps brachii tendon

*median nerve

*radial nerve, dividing into its superficial and deep branches

*Superficial group - pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris

*intermediate group - flexor digitorum superficialis

*deep group - flexor digitorum profundus, flexor pollicis longus, pronator quadratus

*flexors of elbow (minor action), wrist, and digits

*pronators of forearm - pronator teres and pronator quadratus

*major nerve - median (to most muscles)

*minor nerve - ulnar (FCU and ulnar half of FDP)

*lateral - brachioradialis and supinator

*superficial - extensor carpi radialis brevis and longus, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris

*deep - abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis, extensor indicis

*extensors of elbow, wrist, and digits

*supinator of the forearm - supinator

*flexor of the elbow - brachioradialis (exception to the extensor rule)

motor nerve - radial

* flexor digitorum superficialis

*flexor digitorum profundus

*flexor pollicis longus

*median nerve

*NOTE - ulnar nerve and artery and palmaris longus pass on top, radial artery and superficial radial nerve on the lateral side by the scaphoid

*flexor pollicis brevis

*abductor pollicis brevis

*opponens pollicis

innervation - recurrent branch of median nerve

* flexor digiti minimi

*abductor digiti minimi

*opponen digiti minimi

innervated by deep ulnar nerve

* lumbricals

*1st and 2nd lumbricals are innervated by median nerve

*3rd and 4th lumbricals are innervated by ulnar nerve

*adductor pollicis

*7 interosseus muscles - 4 dorsal and 3 palmar (because middle finger can only abduct)

*PAD - palmar adduct - bring fingers together

*DAB - dorsal abduct - spread fingers apart

*innervated by deep ulnar nerve

*snuff box - a roughly triangular depression on the dorsolateral aspect of the hand/wrist

*boundaries -

tendons of the extensor pollicis longus,

extensor pollicis brevis,

abductor pollicis brevis

*contents - 

radial artery

cephalic vein

*synovial tendon sheats - tubular bursae that surround the tendons of the long digital flexor and extensor muscles

*allows gliding/sliding of tendons, especially in areas allowing high mobility or range of motion and/or where tendons cross over and rub against other structures

*radial bursa = digital synovial tendon sheath for flexor pollicis longus

*ulnar bursa = common flexor synovial sheath for flexor digitorum superficialis and profundus

*first degree - pressure on nerve

*second degree - stretching/bruising of nerve

*third degree - lesion (cutting or crushing) of nerve

*complete paralysis = total loss of muscular movement

*incomplete paralysis = weakness of movement relative to normal

*clinical presentation

1)absence/weakness of normal agonist activity

2)atrophy of agonist(s)

3)contracture by antagonists

4)resultant posture -> opposite of actions of affected muscles

*paresthesia - tingling/prickling ("pins and needles")

*hypoesthesia - diminished sensation

*anesthesia - absence of sensation

*upper plexus/upper type disorder: C5, C6 ventral primary rami and/or upper trunk of the brachial plexus

*causes

1)cervicobrachial stretch/separation

2)invasive wounding into posterior triangle of neck

*Nerves involved

1) Musculocutaneous - supplies anterior brachial muscles

2) suprascapular - supraspinatus and infraspinatus

3) axillary - deltoid and teres minor

*classic presentation - waiter-tip posture

a) antagonistic muscles are adducted

b) arm in medial position

c)lateral rotation of shoulder lost

d)power supination lost

*classic cause - axillary trauma to lateral thoracic wall

*motor territory - serratus anterior muscle

*classic presentation

1) winged scapula

2) full abduction deficit - problems raising arm above 90 degrees

*classic causes

1) "crutch palsy" - crutches cause palsy in axillary and radial nerve

2) inferior dislocation of humeral head into quadraungular space (= lateral axillary hiatus)

3) fracture of surgical neck of humerus - possible accompanying vascular trauma

4) compression within narrowed quadrangular space by e.g. tumor, bone callus, scar tissue, muscle hypertrophy

*motor territory - deltoid and teres minor

*cutaneous territory - lateral brachial cutaneous nerve

*classic presentation - weakness of lateral rotation and abduction of the arm (supraspinatus cannot raise the arm to its horizontal level by itself)

*lower plexus/lower type disorder (C8/T1 ventral rami and/or lower trunk of brachial plexus)

a) excessive abduction traction injury ("up and out pull"

b)cervical rib syndrome

c)thoracic outlet syndrome (ex - occult apical lung tumor)

*trauma at medial epicondyle of humerus

a) fracture with posterior displacement of bone fragment(s)

b) elbow dislocations

c) chronic vibration

d) chronic nerve stretch/compression from repetitive motions

e) degenerative elbow joint disease

*ulnar sulcus syndrome - ulnar nerve may be compressed proximal to the elbow near the medial epicondyle

*cubital tunnel syndrome - since ulnar nerve passes thru head of muscle nerve can get trapped

*ulnar tunnel syndrome

*motor territory - hypothenar muscles, lumbricals 3 and 4, 7 interossei, adductor pollicis

cutaneous - 1 1/2 fingers (half of 4th digit and all of 5)

*classic presentation - claw hand aka papal hand aka main en griffe

* crutch palsy

*axillary trauma

a) drunken arm - hanging the arms over the back of a chair for too long, laying on arm too long

 b) inferior dislocation of humerus

*trauma at midshaft (spiral groove) of humerus

a) possible accompanying vascular trauma - deep brachial artery

*supinator syndrome - posterior interossesus  nerve compressed by supinator

*motor territory

1) extension - all extensions of posterior forearm

2) supination - supinator

3) abduction - abductor pollicis longus

*cutaneous territory - posterior arm, posterior middle 1/3 of forearm, 2 1/2 fingers

*classic presentation - wrist drop

weakness of abduction and adduction of the hand

*pronator teres syndrome

*anterior forearm compression or trauma

*anterior interosseous syndrome

*carpal tunnel syndrome - any condition that significantly decreases the size of the carpal tunnel (inflammation of flexor retinaculum, tenosynovitis, blood accumulation) - a major possible consequence is compression necrosis of the median nerve

*penetration wound into base of thenar eminence

*motor territory - all flexors except FCU and ulnar half of FDP

*cutaneous territory - 3 1/2 fingers and posteriorly 3 1/2 nail beds

*classic presentation - ape hand

loss of pronation, opposition of thumb, flexion of lateral tube interphalangeal

 thumb will atrophy and is adducted so it appears short

1. profunda brachii artery

a) ascending (= recurrent branch)

b) radial collateral arteries - anterior and posterior terminal branches

2. superior ulnar collateral artery

3. inferior ulnar collateral artery

1. anterior and posterior ulnar recurrent arteries

2.common interosseous artery

a) anterior

b) posterior

3. deep palmar branch

4. superficial palmar branch

1. radial recurrent

2. superficial palmar branch

3. deep palmar branch

definiton - rerouting of blood using existing alternative pathways

*need to respond to normal temporary occlusions caused by external pressures (ex - pressures of muscle contractions and closing joint angles; kinking of vessels during motion)

*fail-safe system against invasive trauma (ex - blockage, severance)