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**Regulated by androgens
**Regulated by androgens
*If growth teporarily stops -> layer of bone seals the growth plate -> moves into metaphysis when growth resumes -> forms '''Harris lines'''
*If growth teporarily stops -> layer of bone seals the growth plate -> moves into metaphysis when growth resumes -> forms '''Harris lines'''
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===Bone resorption===
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*Mediated by two [[Parathyroid Pathology#Hormonal Control|hormones]]:
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**'''Parathyroid hormone (PTH)'''
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***Produced by <u>chief cells in the parathyroid glands</u> in response to <u>decreased</u> serum calcium
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***In response, osteoclasts increase in number and resorb mineralised matrix - increase Ca in blood
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**'''Calcitonin'''
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***Produced by <u>C-cells in the thyroid glands</u> in response to <u>increased</u> serum calcium
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***Inhibits osteoclasts