Final answer:
A phalanx is a bone in the thumb or one of the fingers, forming the knuckles of the hand. The fingers and thumb have a total of 14 phalanx bones, named after the Greek phalanx. The thumb has two phalanges, while digits 2 to 5 have three each.
Step-by-step explanation:
"Phalanx" is a term used in anatomy to refer to the bones of the fingers and toes. Each digit (finger or toe) is typically composed of several phalanges. The plural form is "phalanges."
Phalanx (singular): Refers to one bone in a finger or toe.
Phalanges (plural): Refers to multiple bones in fingers or toes.
The phalanges are typically categorized into three groups for each digit:
Proximal phalanx: The bone closest to the hand or foot.
Middle phalanx: The bone in the middle of the digit, between the proximal and distal phalanges.
Distal phalanx: The bone at the tip of the digit.
For example, in the fingers, there are three phalanges in each finger except for the thumb, which has two. In the toes, each toe usually has three phalanges.
The term "phalanx" is derived from the Greek word "phalanx," which originally referred to a military formation in which soldiers stood closely packed with shields overlapping. The bone's name was inspired by the arrangement of the finger bones that are closely aligned, resembling a formation of soldiers.