#upper limb

Last revision before my limbs exam in progress. Colouring and the flashcards are really helpful ☺️🤓

HUMERUS 

Upper end

Head articulates with glenoid cavity

2 necks: anatomical & surgical neck

Anatomical 

separates head from greater & lesser tubercles 

Surgical 

 separates upper end & shaft 

has the axillary nerve & circumflex humeral vessels 

2 tuberosities (Mnemonic for insertions: SIT-S)

Greater tuberosity - insertion of

Supraspinatus muscle 

Infraspinatus muscle 

Teres minor muscle

Lesser tuberosity - insertion of:

Subscapularis muscle 

Bicipital groove 

Contains tendon of long head of biceps 

has 3 lips: (Mnemonic: lady between 2 majors)

Medial lip: Teres major insertion 

Floor: Latissmus dorsi insertion 

Lateral lip: Pectoralis major insertion 

Spiral groove 

Lies posteriorly on the shaft 

Related to radial nerve (winds around it between medial & lateral head of triceps) 

Lower end 

Trochlea -- articulates with ulna 

Capitulum -- articulates with radius 

Medial epicondyle more prominent than lateral epicondyle 

3 fossa: olecranon (posteriorly), radial & coronoid (anteriorly) 

FRACTURES OF HUMERUS - NERVES AFFECTED:

Surgical neck -- injury to axillary nerve --effect: flattened shoulder (deltoid muscle) 

Middle of shaft (spiral groove) -- injury to radial nerve -- effect: wrist drop 

Posterior to medial epicondyle -- injury to ulnar nerve -- effect: claw hand