- There are two phalanges in the thumb, named proximal and distal phalanges.
- There are three phalanges in each of the other fingers, named proximal, middle, and distal phalanges.
- The phalanges of a finger along with the associated metacarpal is called a ray.
- The phalanges articulate with:
- the metacarpals proximally, forming the metacarpophalangeal joints.
- each other, forming the interphalangeal joints.
NOTES:
- The word phalanges is plural. Singular for phalanges is phalanx (there is no word phalange).
- Each phalanx is a long bone, therefore it has expanded ends. The proximal expanded end is called the base; the distal expanded end is called the head.
- Because there are only two phalanges in the thumb, the thumb has one interphalangeal joint.
- Because the other fingers have three phalanges each, each finger has two interphalangeal joints, each finger having a proximal interphalangeal joint and a distal interphalangeal joint.