Skel A-MEtabolic Bone Disease Flashcards Preview

Skeletal Radiology A > Skel A-MEtabolic Bone Disease > Flashcards

Flashcards in Skel A-MEtabolic Bone Disease Deck (84)
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1

Descriptive term for decreased bone or increased radiolucency of bone that occurs when bone resorption exceeds bone formation regardless of specific pathogenesis.

Osteopenia

2

What results when bone resorption exceeds bone formation regardless of specific pathogenesis?

Osteopenia

3

T/F: Radiographic findings of osteopenia does not alone allow a precise diagnosis

True

4

What are the four major causes of osteopenia?

Osteoporosis

Osteomalacia/ Rickets

Hyperparathyroidism

Neoplasm

5

Bone Cells:

Originates from the marrow stem cells, develop into osteoblasts

Osteoprogenitor cells

6

Bone cells:

Produces osteoid which is soft material main of 90-95% collagen and 5-10% ground substance, the mucopolysaccharide.

It is numerous in growing skeleton and decrease in number and size at maturity

OSTEOBLAST

7

Bone cell:

Arises from osteoblast that become entrapped in their own osteoid.

They maintain bone integrity

Mature bone cells

Osteocytes

8

Bone Cells:

Inactive/dormant osteoblast

Bone lining cells

9

Bone Cell:

Bone resorptive cells, derived from hematopoietic monocyte lineage.

Different lineage from other bone cells

Osteoclast

10

For normal bone density what is required

Osteoblastic=Osteoclastic activity

Normal nervous system function

Normal GI, Liver, Renal Function

Dietary intake of calcium and phosphorus

Normal endocrine function

Weight bearing exercises

11

Non-cellular constituents of bone:

% of wet weight of bone that is accounted for by water

20%

12

Non-cellular constituents of bone:

% of bone weight accounted for by cellular components

Tiny fraction

13

Non-cellular constituents of bone:

% of dry bone weight accounted for by organic matrix/osteoid

30%

14

Non-cellular constituents of bone:

% of dry bone weight accounted for by inorganic material

70%

Accounts for 70% of osseous tissue

15

Non-cellular constituents of bone:

Inorganic material exists as what ?

Calcium hydroxyapatite

16

Calcium homeostasis:

Function of the skeleton in calcium homeostasis

99% of calcium stored in skeleton

Serves as a reserve for serum calcium

17

Calcium homeostasis:

70% of plasma calcium is believed to be maintained how?

Continuous exchange of calcium ions between bone and extracellular fluid

18

Calcium homeostasis:

The remaining 30% of plasma calcium is mediated by what?

The function of Parathyroid hormone and Calcitonin

19

Osteoclast and Osteoblast function:

Osteoclast exist in pits on bone surfaced called?

Resorption bays or Howship’s Lacunae

20

Osteoclast and Osteoblast function:

Osteoclast function

Secretion of Collagenase to break down osteoid

Secrete Acid to break down calcium hydroxyapatite

21

Osteoclast and Osteoblast function:

What are substances that can have direct or indirect influence on osteoclasts increasing their function or numbers or both?

Parathyroid hormone

Active Vitamin D

Prostaglandin E2

Thyroid hormone

Heparin

22

Osteoclast and Osteoblast function:

Substance that inhibits osteoclast

Calcitonin

23

Metabolic bone disease:

Bone quantity not quality disorder

Associated with decreasing osteoblastic function with age

Estimated 30-50% loss before detectable radiographically

Osteoporosis

24

Metabolic bone disease:

Where is the predominant location of osteoporosis ?

Axial skeleton

Proximal long bones

*can be generalized of localized

25

Metabolic bone disease:

Senile Osteoporosis is (men/women)

Post-menopausal osteoporosis is (men/women)

Senile-men

PM- women

26

Metabolic bone disease:

Inadequate mineralization of osteoid

Related to deficiency in calcium, vitamin D or phosphorus which can be

Deficiency caused by renal disease, sunlight deficiency, liver disease, dietary insufficiency and GI Disease

Osteomalacia

27

Metabolic bone disease:

Primary type of HPT characterized by?

Increase PTH production usually benign adenoma

28

Metabolic bone disease:

With Primary HPT you will see (hypercalcemia/hypocalcemia)

Hypercalcemia

29

Metabolic bone disease:

Secondary HPT Characterized by?

Abnormal stimulation of glands by sustained hypocalcemia and hyperphosphatemia

30

Metabolic bone disease:

Potential causes of secondary HPT

Renal disease

GI Malabsorption