Anatomy and Physiology I Skeletal System Case Study Taylor Phillips is a 27-year
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Question
Anatomy and Physiology I
Skeletal System Case Study
Taylor Phillips is a 27-year-old female pharmaceutical representative with a lifetime history of good health. She played Division II soccer in college, and has participated in a competitive weekend soccer league since graduation. Last week, Taylor broke her hip in a fall on the soccer field. Doctors want to be certain that Taylor’s fracture is due to the impact of the fall, and not an underlying health issue. A blood test is ordered, and abnormalities are noted. Results from Taylor’s blood tests are as follows:
Test
Taylor
Normal Range
Flag (“x” if yes)
RBC Count (million/ul)
4.7
4.5 – 5.3
Hematocrit (%)
41
37 – 45
WBC Count (per ul)
7500
5000 – 10,000
Platelet Count
272,000
150,000 – 400,000
Serum Iron (mcg/dL)
92
60 - 170
TSH (for Thyroid Hormone; mIU/L)
1.87
0.50 – 4.50
PTH (Parathyroid Hormone; pg/ml)
132
10 – 65
Calcitonin (pg/ml)
3.6
<6.5 pg/ml
Calcium (mg/dL)
11.8
9.0 – 10.5 mg/dL
Protein, Total g/dL
6.4
6.2 – 8.3
Lyme Western Blot
Negative
Epstein Barr Virus (IgG, IgM)
Negative
ANA Screen
Negative
Rheumatoid Factor (IU/mL)
< 7
<14
Questions
1. Which of Taylor’s blood test results are abnormal?
2. Do you think the abnormalities contributed to Taylor’s fracture?
3. Name the glands that secrete PTH. Where are these glands located?
3. Under normal circumstances, what conditions stimulate PTH release?
4. How does PTH impact blood calcium levels? How does PTH exert its effect?
5. Where is most calcium stored in the body?
6. Name three physiological functions that require calcium.
7. Calcitonin is an antagonist of PTH. Where is this hormone produced? How does this
hormone impact blood calcium levels?
8. Doctors order a bone density scan (BMD – Bone Mineral Density) and note that Taylor
had osteopenia, an early indicator of osteoporosis. Define osteoporosis. How does calcium
impact bone health?
9. Taylor was found to have a tumor on one of her parathyroid glands. The tumor caused the gland
to secrete abnormally high levels of PTH (called hyperparathyroidism). Imagine you are the
doctor. Explain to Taylor the relationship between the parathyroid tumor and her broken hip.
10. What do you think Taylor’s course of treatment will be?
Test
Taylor
Normal Range
Flag (“x” if yes)
RBC Count (million/ul)
4.7
4.5 – 5.3
Hematocrit (%)
41
37 – 45
WBC Count (per ul)
7500
5000 – 10,000
Platelet Count
272,000
150,000 – 400,000
Serum Iron (mcg/dL)
92
60 - 170
TSH (for Thyroid Hormone; mIU/L)
1.87
0.50 – 4.50
PTH (Parathyroid Hormone; pg/ml)
132
10 – 65
Calcitonin (pg/ml)
3.6
<6.5 pg/ml
Calcium (mg/dL)
11.8
9.0 – 10.5 mg/dL
Protein, Total g/dL
6.4
6.2 – 8.3
Lyme Western Blot
Negative
Epstein Barr Virus (IgG, IgM)
Negative
ANA Screen
Negative
Rheumatoid Factor (IU/mL)
< 7
<14
Explanation / Answer
PTH serves to increase blood calcium level & preserves blood calcium by several major effects:
Bone: PTH stimulates bone resorption releasing calcium from bone.
Kidney: PTH maximizes tubular reabsorption of calcium within kidney.
Intestine: Intestines are stimulated to increase calcium absorption. 1,25-DHCC promotes calcium absorption in small intestine. For vitamin D to exert this effect, it must be converted by kidneys to its active form-it is this conversion that is directly stimulated by PTH.
5. Bones act as a vast reservoir of calcium, it is the place where most of the calcium in the body is stored.
6. Three physiological functions that require calcium are:
7. Calcitonin (CT) is secreted from C cells of thyroid gland.
CT is a physiological antagonist to PTH with regard to Ca++ homeostasis & functions to reduce blood calcium levels.
8. Osteoporosis is characterized by the following feature:-
Bone reabsorption outpaces bone deposit; bones become lighter and fracture easier. Any bone in the body can be affected by osteoporosis, but the most common places where fractures occur are the back (spine), hips, and wrists.
9. PTH stimulates bone resorption releasing calcium from bone. It facilitates mobilization of calcium & phosphate from bone into blood. PTH activates osteoclasts & induces their lysosomal enzymes.
Since you had a tumor in one of your parathyroid glands, it resulted in hypersecretion (excess secretion) of PTH. This resulted in more bone-resorption, and hence your bones became lighter & prone to fracture.
10. Removal of the tumor in the parathyroid gland surgically.
Taking care of the hip fracture.
(Treatment with EDTA to remove excess calcium in blood.)