Calcium metabolism

Question 1

What problem does High ALP (alkali phosphatase) signpost?
And how do we know its that problem?

Answer 1

High Bone turnover, although can be other problems such as liver or Biliary tract problem.
High Calcium indicates high bone turnover.

Question 2

What effect does parathyroid hormone (PTH) normally have on vitamin D synthesis

Answer 2

Increases Vitamin D synthesis, (in order to absorb more Calcium ions from the GI tract)

Question 3

What are the two main mechanisms by which malignancy causes hyperglycaemia

Answer 3

1. Haematological malignancies (eg myeloma) and those that metastasise to bone, produce local factors that cause excessive osteoclast activity.
2. Squamous tumours of lung and head and neck, produce PTHrp - parathyroid hormone -related peptide which acts on PTH receptors.

Question 4

What cell in parathyroid glands releases PTH

Answer 4

Chief Cell