Chapter 16

The formation of blood cells occurs within what component of the bones?

There are four critical functions of bones: protection of internal organs, support of the body, blood cell production, and regulation of internal calcium concentration. Discuss how bones conduct each of these four tasks.

What are the structural and functional differences between the diaphysis and the epiphysis locations within long bones?

. Spongy bone can withstand stresses that arrive from multiple directions, whereas compact bone can normally withstand stresses in only one direction. Why is there this difference and what structures account for this difference?

What are the functions of the four types of bone cells?

If the synovial fluid is not formed properly, there is the possibility for the cartilage at the ends of the bone to come into contact with each other. How can synovial flow be reestablished and what would happen if it were not reestablished?

Calculate the change in molecular volume of the synovial fluid if the formation rate of synovial fluid by the synovial membrane is 6.5 mg/h/cm2 and by the cartilage is 73 ng/h/cm2 . Assume that the synovial membrane area is 15 mm2 and that of the cartilage is 25 mm2 . The degradation rate of the synovial fluid is 23 ng/h, and the flux of synovial fluid out of the membrane is 0.97 mg/h.

Calculate the restricted diffusion coefficient for proteoglycans within the synovial fluid if the time rate of change of proteoglycans within synovial fluid is 0.095 mg/h. The free diffusion for proteoglycans in water is 1.25E e 7 cm2 /s. Assume that the degradation rate for proteoglycans is negligible and that the formation rate for proteoglycans within the synovial membrane and the cartilage is 2.2 mg/h/cm2 and 31 ng/h/cm2 , respectively. The area of the synovial membrane is 15 mm2 and that of the cartilage is 25 mm2 . The permeability of this proteoglycan through the synovial membrane is 1.23E e 6 cm/s, and the concentration gradient for this proteoglycan is 0.07 mg/mL.

Calculate the stress on the cartilage and the change in length of cartilage, assuming that the force on the cartilage is 9875 N and that the diameter of the cartilage is 2 cm (assume that the cartilage has a circular area). The cartilage has a thickness of 1.5 mm and an elastic modulus of 250 MPa.

Discuss the movement of solutes within and to bone cells. Why is a robust lymphatic system missing from the Haversian canal system? What do you think is the primary mode of delivery and reuptake of solutes in bone?