Final answer:
The tubelike, hollow space in the diaphysis of a long bone filled with yellow marrow in adults is known as the medullary cavity. The medullary cavity's walls are made of compact bone, while the epiphyses contain spongy bone and red marrow.
Step-by-step explanation:
The part of a long bone that is tubelike, hollow, and found in the diaphysis, filled with yellow marrow in adults, is called the medullary cavity. This cavity runs the length of the diaphysis and its walls are comprised of dense, hard compact bone. The medullary cavity, which contains yellow marrow, plays a role in the storage of fats and serves as a passageway for nutrient arteries and veins.
In addition, the epiphyses are located at each end of a long bone, such as the femur, tibia, ulna, and radius. They are filled with spongy bone and red marrow, which is involved in the production of blood cells. These structures meet the diaphysis at the metaphysis, which includes the epiphyseal plate, referred to as the growth plate in growing bones, and which later turns into the epiphyseal line once bone growth ceases in early adulthood.