The main structure of palm/hand is made up of the collection of bones called the metacarpals. These are 5 cylindrical bones which connect finger bones (phalanges) to the wrist bones (carpals). Each of the five metacarpal bones leads to a single finger bone. They are referred to as number one to five, for e.g. first metacarpal, second metacarpal etc. Number one connects to the thumb and the number five connects to the little or pinky finger. The points of connection with the fingers are called knuckles. The first metacarpal bone is the shortest, broadest, and more robust of the five. The second metacarpal is the longest and has the largest base, of all the metacarpals. The third metacarpal connects to the middle finger and is the only metacarpal to have a bony projection at the base called styloid process. The fourth metacarpal is shorter with a fairly square base. The fifth metacarpal is the thinnest.
Function
The shape of the first metacarpal allows for the movement of the thumb that enables you to grasp objects easily. The common function of these bones is to help the fingers move.
Disease/ Injury/ Fracture
Metacarpals can get fractured due to a fall if the person lands on his/her hand or sports injury where there is a significant amount of impact to the hands. Fist fight can lead to fracture too.
Next time you look at your palm, remember there are bones called metacarpals inside!
