Msk Week 2 Objective 3 (G,h)

Front 1

What type of collagen is found in bone osteiod, what cell synthesizes it?

Back 1

Type 1 collagen, produced by the osteoblast.

Front 2

With respect to the synthesis of Type 1 collagen, identify the potential markers found in the serum that could be used as biochemical markers for synthesis.

Back 2

Serum: procollagen 1 carboxy- and amino- terminal peptides.

Primer on Rheumatic Diseases CH:35

Front 3

With respect to the synthesis of Type 1 collagen, identify the potential markers found in the serum and urine that could be used as biochemical markers for degradation.

Back 3

Serum: Type 1 collagen carbony- and amino- terminal peptides.
Urine: Type 1 collagen carbony- and amino- terminal peptides; and pyridinoline type 1 collagen cross-links.
Primer on Rheumatic Diseases CH:35

Front 4

Briefly describe the stages of type 1 collagen synthesis:

Back 4

Intracellular
1. 3 alpha chains assemble in RER and hydroxylated, glycosolated in the golgi to form PROCOLLAGEN helix.
2. Procollagen is package into vesicles.
3. Vesicle are exocytosied in to the ECM.
Extracellular
4. Procolagen end carboxy- and amino- peptides cleaved to form TROPOCOLLAGEN which aggregate to form FIBRILS.
5. Tropocollagen fibrils are reinforced by covalent cross-links
6. spontaneous aggregation of x-liked fibrils to form COLLAGEN FIBERS.

Front 5

Describe the polymerization pattern in Type 1 collagen.

Back 5

Type 1 collagen tropocollagen molecules polymerize in a staggered pattern, producing long fibrils that, under high magnification, appear to be striated fibers with ha repeat periodicity of 64nm.

Front 6

Identify the main organic and inorganic components of the bone matrix, what property does each contribute to the bone?

Back 6

Organic: Type 1 collagen: tensile strength
Inorganic: hydroxyapatite: compressive strength

Front 7

What bone cell secretes Alkaline phosphatase?

Back 7

Osteoblast

Front 8

Describe the mineralized component of bone, what functionality does his add to the bone?

Back 8

The mineralized component of bone, hydroxyapatite, consists of calcium and phosphate. It is deposited on the collagen matrix scaffolding to provide compressive strength.

Front 9

What is the term given to defective bone mineralization?

Back 9

Children: Rickets
Adults: Osteomalacia

Front 10

On your pediatric rotation you see a young boy with soft bones, what is the most probable cause for this?

Back 10

Vitamin D deficiency, leading to improper bone mineralization, and a diagnoses of Rickets.

Front 11

You have a male patient on B-interferon therapy for Hepatitis C. You monitor their liver function routinely every 6 months to make sure the interferon is not casuing hepatocyte damage. This last liver panel you discover elevated ALP, however, ALT, AST, and GGT, and other liver function tests are all normal. What other cells contain ALP, what process can you infer is happening in this patient?

Back 11

ALP is present in the cells of the bililary duct, placenta, and bone.

Since liver function tests are all normal we can rule out a liver problem, our patient is male so we can rule out a placental source, therefore the ALP must originate from the bone cells. This would indicate osteoblast actively; they secrete ALP which increases mineralization of the organic osteiod matrix.

Front 12

You have a male patient on B-interferon therapy for Hepatitis C. You monitor their liver function routinely every 6 months to make sure the interferon is not casuing hepatocyte damage. This last liver panel you discover elevated ALP, however, ALT, AST, and GGT, and other liver function tests are all normal. What other cells contain ALP, what process can you infer is happening in this patient?

Back 12

ALP is present in the cells of the bililary duct, placenta, and bone.

Since liver function tests are all normal we can rule out a liver problem, our patient is male so we can rule out a placental source, therefore the ALP must originate from the bone cells. This would indicate osteoblast actively; they secrete ALP which increases mineralization of the organic osteiod matrix.