Anatomy: Shoulder & Arm Flashcards
Where is the greater tubercle of the humerus?
Lateral
Where is the lesser tubercle of the humerus?
Posterior
What is the significance of the surgical neck?
Commonly fractured
Where does the coracoid process point?
Humerus head
What happens to the scapula during abduction?
Lateral rotation
What gives the shoulder so much mobility?
Ability of the scapula to glide and rotate
Serratus anterior OIAI
Ribs
Scapular medial birder
Laterally rotates and protracted scapula
Long thoracic nerve (C5-7, superficial side)
What is winged scapula?
Transsection of the long thoracic nerve paralyzed serratus anterior
What are the three groups of shoulder muscles?
Superficial posterior
Deep posterior
Scapulohumeral
What are the superficial posterior shoulder muscles?
Traps
Lats
What are the deep posterior shoulder muscles?
Levator scapula
Rhomboids
What innervates the deep posterior shoulder muscles?
C5
What are the scapulohumeral muscles?
Deltoid Teres major Supraspinatus Infraspinatus Subscapularis Teres minor
Deltoid OIAI
Clavicle, scapula
Deltoid tuberosity
Abductor
Axillary nerve (C5)
What is a complication of surgical neck fractures?
Axillary nerve damage
Teres major OIAI
Scapula
Bicipetal groove
Adduction
Lower subscapular nerve (C5-6)
What makes up the rotator cuff?
Supra
Infra
Teres minor
Sub
Where do the rotator cuff muscles insert? Innervation?
Supra- greater tubercle (suprascapular nerve)
Infra- greater tubercle (suprascapular nerve)
Sub- lesser tubercle (upper & lower subscapular nerves)
Teres minor- greater tubercle (axillary nerve)
Where does the supraspinatus tendon travel?
Subacromial space
What separates the supraspinatus from the acromion?
Subacromial bursa
What is the most commonly injured rotator cuff muscle?
Supra
What travels through the suprascapular notch?
Suprascapular nerve ( under ligament) Suprascapular artery (over ligament)
What are the boundaries of the Quadrangular space?
Teres major/minor
Long head of triceps
Surgical neck of humerus
What is the function of the clavicle?
allows the scapula to glide along the wall
What is the most commonly broken bone?
clavicle
What lies under the clavicle?
brachial plexus
subclavian artery/vein
Where does the upper extremity articulate with the axial skeleton?
sternoclavicular joint
What ligaments support the SC joint? (4)
anterior SC
posterior SC
interclavicular
costoclavicular
What kind of joint is the SC?
synovial with intra-articular disc
What kind of joint is thte AC?
synovial
What ligaments support the AC?
acromioclavicular
coracoclavicular* (pair)
What is a 2nd degree AC injury?
subluxation, rupture of AC ligament
What is a 3rd degree AC injury?
dislocation, rupture of all three ligaments
What is a 1st degree AC injury?
sprain, injury but no rupture
What are the anterior thoracoappendicular muscles?
pecs
subclavius
serratus anterior
Pec major OIAI
clavicle/sternum
lateral lip of bicipetal groove
adductor and internal rotator
medial and lateral pectoral nerves
Pec minor OIAI
ribs
coracoid
stabilizes scapula
medial pectoral nerve
What goes under the pec minor?
axillary artery/vein
brachial plexus
What is the subscapular artery vascularize?
scapula, turns into the thoracodorsal
Waht do the a/p humeral circumflex vascularize?
humerus
What are the five segments of the brachial plexus?
roots trunks divisions cords branches
What spinal nerves form the brachial plexus roots?
C5 - T1 (5 roots)
What are the trunks of the brachial plexus?
Superior (C5-6)
Middle (C7)
Inferior (C8-T1)
What are the divisions of the brachial plexus?
anterior and posterior of each trunk
What do the anterior divisions innervate?
anterior (flexor) muscles
What do the posterior divisions innervate?
posterior muscles
What are the cords of the brachial plexus?
lateral (anterior superior/middle)
medial (anterior inferior)
posterior (all posterior)
What are the 5 branches?
musculocutaneous (C5-7) axillary (C5-6) radial (C5-T1) median (C5-T1) ulnar (C8-T1)
What branches does the lateral cord give?
musculocutaneous
median
What branches does the medial cord give?
median
ulnar
What branches does the posterior cord give?
axillary
radial
What muscles surround the roots of the brachial plexus?
middle and anterior scalenes
What does the axillary sheath originate from?
prevertebral fascia
What is in the axillary sheath?
brachial plexus
axillary artery
How are the cords of the brachial plexus named?
relation to the axillary artery
What non-plexus nerve provides sensation to the armpit?
intercostobrachial nerve (T2)
Wha inserts into the supraglenoid tubercle?
biceps long head
What overlies the lateral condyle?
capitulum
What overlies the medial condyle?
trochlea
What fossas are on the anterior distal humerus?
radial
coranoid
What runs in the radial groove of the humerus?
radial nerve
deep brachial artery
What runs in the ulnar groove?
ulnar nerve
What does the axillary nerve wrap around?
surical neck
What are perforating veins?
connect deep and superficial veins
What are the superficial veins of the arm?
basilic (medial)
cephalic (lateral)
What is the association between deep veins and arteries?
two veins with artery in the middle
Where does the cephalic vein go deep?
deltopectoral triangle
Where is the median cubital vein?
antecubital fossa
What are the four sections of deep fascia of the arm?
brachial
pectoral
deltoid
antebrachial
What divides the arm into a/p compartments?
septa from brachial fascia
What muscles are in the anterior compartment of the arm? Innervation?
biceps
brachilais
coracobrachialis
I - musculocutaneous
Biceps brachii OIAI
O - coracoid, supraglenoid tubercle
I - radial tuberosity
A - supination, flexion (2 joints)
I - musculocutaneous
Which muscles in general are most likely to tear?
those that cross 2 major joints
Brachialis OIAI
O - distal humerus
I - ulna
A - chief flexor
I - musculocutaneous
coracobrachialis OIAI
O - coracoid
I - middle humerus
A - adductor
I - musculocutaneous (pierces this muscle)
What does the musculocutaneous innervate?
anterior compartment arm muscles
What does the lateral cutaneous originate from?
musculocutaneous
What does the lateral cutaneous nerve do?
sensation to lateral forearm
What accompanies the brachial artery?
median nerve
What are the branches of the brachial artery?
deep brachial
superior & inferior ulnar collateral
Triceps OIAI
infraglenoid tubercle, posterior humerus (distal and proximal)
olecranon process
extensor
radial nerve (C6-8)
Where does the radial nerve run?
triangular interval (between triceps heads) with the deep brachial artery
What are all extensors in the arm/forearm innervated by?
radial nerve
What is the function of the glenoid labrum?
surround the humerus and deepen the glenoid cavity
What holds the humerus in the glenoid cavity?
rotator cuff tendons
fibrous capsule
biceps tendon
What holds the biceps tendon in the bicipetal groove?
transverse humeral ligament
What is the function of the coracoacromial ligament?
prevent superior dislocation
What is commonly torn in GH dislocations (3)? Most common direction?
direction: anterior-inferior
labrum
anterior capsule
subscapularis tendon
What innervates the medial skin of the upper limb?
medial cutaneous nerve of arm and forearm
What innervates the lateral arm?
superior lateral cutaneous nerve (from axillary)
What happens after the labrum is torn?
GH easily dislocates afterwards