Tulang panjang, or long bones, are a type of bone found in the human body. They are characterized by a long shaft and two ends, which are typically larger than the shaft. Examples of long bones include the femur, humerus, and tibia. These bones are essential for supporting the body's weight and facilitating movement. Long bones are primarily made of a hard outer layer called cortical bone and a spongy inner layer known as trabecular bone. They also contain bone marrow, which is responsible for producing blood cells. The growth and development of long bones occur at the epiphyseal plates during childhood and adolescence.