Final answer:
The femur, or thighbone, is the longest and heaviest bone in the human body, forming part of the hip and knee joints. The tibia is the second-largest bone and is crucial for weight transmission. Short bones provide stability and support.
Step-by-step explanation:
The longest and heaviest bone in the human body is the femur, also known as the thighbone. The femur is a crucial component of our skeletal system as it forms joints at both ends - the hip joint at the proximal end with the pelvis, and the knee joint at the distal end with the tibia and patella. The tibia is the second largest bone in the human body, crucial for transmitting the weight from the femur to the foot, while the fibula serves primarily as a site for muscle attachment and forms part of the ankle joint. Short bones, like those in the wrists and ankles, provide support and stability.