Final answer:
The five long bones in the hand that articulate with the proximal phalanges are the metacarpal bones, numbered 1 to 5 starting with the thumb side.
Step-by-step explanation:
The five long bones of the hand that articulate with the proximal phalanges are known as the metacarpal bones. These bones form the structure of the palm and are sequentially numbered from 1 to 5, starting from the side of the thumb (digit number 1) towards the little finger (digit number 5).
The articulation occurs at the metacarpophalangeal joints, and these connections are critical for hand function, facilitating movements such as gripping.
The first metacarpal bone supports the thumb, which has two phalanges - a proximal and a distal phalanx. Digits 2 through 5 have three phalanges each: proximal, middle, and distal. The expanded distal ends of the metacarpal bones form the knuckles of the hand at the base of the fingers.