Shoulder girdle and upper limb


  • The upper limb forms a joint with the trunk via the shoulder girdle
  • The shoulder girdle consist of two clavicles and two scapula .


Clavicle (collar bone )

  • S-shaped long bone
  • It's articulate with the manubrium of the sternum at the sternoclavicular joint and forms the acromioclavicular joint with the acromion process of the scapula .


Scapula (shoulder blade )

  • Triangular shaped bone , lying on the posterior chest wall superficial to the ribs and separate from them by muscles
  • At the lateral angle is a shallow articular surface , the glenoid cavity , which with the head of the humerus,forms the shoulder joint. (At the lateral angle could be a shallow body part surface , the glenoid fossa , that with the top of the arm bone,forms the cotyloid joint.)
  • Highest point of the shoulder is called the acromion process and forms a joint with the clavicle the acromioclavicular joint , a slightly movable synovial joint that contribute to the mobility of the shoulder girdle .
  • The coracoid process a projection from the upper border of the bone gives attachment to muscles that move the shoulder joint .

Humerus

  • Upper arm bone
  • Head sists with in the glenoid cavity of the scapula
  • The greater and lesser tubercles , and between them there is a deep groove.
  • The bicipital groove or intertubercular, occupied by one of the tendons of the biceps muscle
  • The distal end of the bone presents two surfaces that articulate with the radius and ulna to form the elbow joint


Ulna and radius

  • Two bones of the forearm
  • They articulate with the humerus at the elbow joint . The carpal bone at the wrist joint and with each other at the proximal and distal radioulnar joint.
  • In addition an interosseous membrane , a fibrous joint , connects the bone along their shaft stabilising their association and maintaining their relative position despite forces applied from the elbow or wirst


Carpal (wrist bones )

  • 2 rows
  • Proximal row - scaphoid , lunate , triquetrum , pisiform
  • Distal row - trapezium , trapezoid , capitate , hamate
  • These bones are closely fitted together with ligament and help in position and limited amount of movment
  • Tendons of muscles lying in the forearm cross the wrist and are held close to the bones by strong fibrous bands , called retinacular.


Metacarpal bone

  • The proximal end articulate with the carpal bones and distal ends with the phalanges


Phalanges

  • 14 phalanges , three in each finger and two in the thumb .
  • They articulate with the metacarpal bones and with each other , by hinge joint.