Topic 8 Skeletal System: Bone Structure

Question 1

• Highly organized, dense bone that doesn’t appear to have cavities from outside. This bone constantly remodels:

Answer 1

Compact Bone

Question 2

a. Haversian canals
b. Lamellae
c. Lacunae
d. Volkmann’s canals
e. Osteon
f. Medullary Cavity

Answer 2

Things occurring in Compact Bone

Question 3

• Osteoclasts burrow tunnels that form these canals

Answer 3

a. Haversian canals

Question 4

• Osteoclasts are followed by osteoblasts, which lay down new matrix onto tunnel walls, forming concentric rings or lamellae

Answer 4

b. Lamellae

Question 5

• Osteocytes trapped between the lamellae reside in a space called the lacunae and exchange nutrients via small canals (canaliculi)

Answer 5

c. Lacunae

Question 6

• The Haversian canal contains nerves, blood vessels, and lymph vessels, which are connected by Volkmann’s canals

Answer 6

d. Volkmann’s canals

Question 7

• Entire system of lamellae + Haversian canals

Answer 7

e. Osteon

Question 8

• Compact bone surrounds the medullary cavity which is filled with yellow bone marrow that contains adipose cells for fat storage

Answer 8

f. Medullary Cavity

Question 9

• Less dense bone that consists of an interconnecting lattice of bony spicules called trabeculae. Filled with red bone marrow, which is site of hemopoiesis, or RBC development

Answer 9

2. Spongy (cancellous) Bone

Question 10

• typically has a long shaft (diaphysis) and two ends, each composed of a metaphysis and epiphysis. A sheet of cartilage is found between the metaphysis and epiphysis, called the epiphyseal plate, which is also the location of bone growth. Bone increases in both length and diameter along the diaphysis as well

Answer 10

3. Long Bone

Question 11

• Bones function in mineral homeostasis. In the blood, calcium salts are only slightly soluble, and most of the Ca2+ in the body is stored in bone matrix as hydroxyapatite (a calcium phosphate mineral). This matrix, alongside collagen fibers, provides great tensile and compressive strength.
• Calcium phosphate (CaHPO4) is the main calcium compound in bond. 99% of calcium in the body is contained in bones and teeth
• If stress is put on the bone, osteoblasts deposit collagen and release calcium phosphate to strengthen the bone – the mineral hydroxyapatite is produced
• Bones can be made from a combination of compact and spongy bone

Answer 11

4. Mineral Homeostasis