arm

An arm is a part of the human body that is located between the shoulder and the hand. It is used for a variety of tasks, such as reaching, grasping, and holding objects.

The arm is made up of three bones: the humerus, the radius, and the ulna. The humerus is the longest bone in the arm, and it connects the shoulder to the elbow. The radius and the ulna are the two bones that run from the elbow to the wrist.

The arm is also home to a number of muscles, tendons, and ligaments. These structures allow the arm to move in a variety of ways.

In science, the arm is often used as a unit of measurement. For example, the length of a piece of paper might be measured in arms.

The boy's arm was bruised from falling off his bike.