Long bones are a type of bone characterized by their elongated shape and are primarily found in the limbs. They consist of a shaft called the diaphysis and two ends known as epiphyses. Long bones are crucial for movement and support, as they act as levers for muscles. These bones are primarily made of compact bone tissue, which provides strength, and contain a central cavity filled with bone marrow. Examples of long bones include the femur in the thigh and the humerus in the upper arm. Their structure allows for growth and the ability to withstand stress.