Ch. 7: Bone Structure and Function (Learnsmart Quiz)

Select all the combined effects of parathyroid hormone and calcitriol: - Bone resorption by osteoclasts - Activation of osteoclasts - Increase excretion of calcium by the kidneys - Increase absorption of calcium by the small intestine

All except increase excretion

Select all that are true of bone remodelling: - Remodelling occurs at about the same rate everywhere in the skeleton - Osteoclasts are involved in the remodelling process - Bone remodelling is a combination of bone deposition and resorption - Bones are remodelled to accommodate the stresses put on them

All except remodelling

Which step in the formation of calcitriol is regulated by parathyroid hormone? - Conversion of calcidiol to calcitriol - Conversion of 7-dehydrocholesterol to Vitamin D3 - Conversion of Vitamin D3 to calcidiol - Conversion of calcidiol to cholecalciferol

Conversion of calcidiol to calcitriol

Appositional growth requires: - Resorption on the external surface of a bone - Osteoblast depositing new bone within the medullary cavity - Deposition of external circumferential lamellae - A narrowing medullary cavity as new bone is deposited around it

Deposition of external circumferential lamellae

Appositional growth occurs within the epiphyseal plate

False

Indicate if the listed hormone increases or decreases blood calcium levels: Parathyroid hormone Calcitonin

Increases Decreases

Select all that are true of calcitonin: - Helps decrease blood calcium - More effective in children than adults - Inhibits osteoclast activity - Signals the kidneys to decrease the loss of calcium in the urine

More effective in children than adults Inhibits osteoclast activity

Age-related loss of minerals resulting in insufficient ossification and thinner, weaker bones is called _______________

Osteopenia

Parathyroid hormone is released from the ________________ glands

Parathyroid

Hyaline cartilage: - Serves as a precursor for the formation of long bones in the body - Has a double-layered connective tissue sheath covering it called the periosteum - Can be found in between vertebrae serving as shock absorbing discs - Is flexible and composed of elastin

Serves as a precursor for the formation of long bones in the body

Match the components of the epiphyseal plate with the correct description

The area nearest to the epiphysis that contains randomly arranged chondrocytes - zone of resting cartilage Chondrocytes produce new cartilage, divide, and form columns resembling stacks of coins - zone of proliferation Chondrocytes mature and enlarge, the cells nearest the diaphysis are undergoing hypertrophy - zone of hypertrophy The very thin zone that contains hypertrophied chondrocytes and calcified cartilage matrix - zone of calcification The area where calcified cartilage is replaced by bone - ossified bone

Select the correct word from the list to complete each sentence. Not all terms will be used.

The hormone that indirectly stimulates osteoclasts to break down bone and release calcium into the blood is parathyroid hormone Osteoclasts are inhibited by calcitonin Bone cells that remove calcium from the blood to make bone are osteoblasts In the kidneys, PTH increases calcium reabsorption from the urine In the kidneys, PTH also promotes the formation of active vitamin D Active vitamin D increases calcium absorption from the small intestine

Lack of sunlight will directly affect the formation of: - Vitamin D3 (cholecalciferol) - 7-dehydrocholesterol - Calcium - Parathyroid hormone

Vitamin D3 (cholecalciferol)