The upper limb is divided into three regions:

  • The arm, located between the shoulder and elbow joints;
  • The forearm, which is between the elbow and wrist joints;
  • The hand, which is located distal to the wrist.

There are 30 bones in each upper limb:

  • The humerus is the single bone of the upper arm.
  • The ulna (medially) and the radius (laterally) are the paired bones of the forearm.
  • The base of the hand contains eight bones, each called a carpal bone.
  • The palm of the hand is formed by five bones, each called a metacarpal bone.
  • The fingers and thumb contain a total of 14 bones, each of which is a phalanx bone of the hand.