The Endocrine System and Vitamin D

Which type of cells in the parathyroid gland produce PTH?

Chief cells

What is the function of oxyphil cells in the parathyroid gland?

Unknown function

What is the half-life of PTH?

5-10 minutes

Which hormone is involved in the regulation of calcium levels in the blood?

All of the above Signup and view all the answers

What is the main function of osteoclasts?

Degrade bone tissue Signup and view all the answers

What is the direct effect of PTH on the kidneys?

Both A and B Signup and view all the answers

Which organ is responsible for transforming vitamin D into its biologically activated form?

Kidneys Signup and view all the answers

What is the most important pool for physiological control of calcium concentrations in the blood?

Bones Signup and view all the answers

What is the main function of calcitriol?

Increases absorption of calcium by the GI tract Signup and view all the answers

Which enzyme converts calcidiol 25(OH)D into calcitriol 1,25(OH)₂D?

1-alfa-hydroxilase Signup and view all the answers

Which hormone stimulates the active transport of dietary calcium across the intestinal epithelium?

PTH Signup and view all the answers

Which gland produces calcitonin?

Thyroid gland Signup and view all the answers

What is the main effect of calcitonin on bone metabolism?

Increases storage of calcium in the bones Signup and view all the answers

What is the main symptom of primary hyperparathyroidism?

Polydipsia and polyuria Signup and view all the answers

Which of the following is true about the parathyroid glands?

The parathyroid glands are located in the thyroid glands. Signup and view all the answers

What is the role of PTH (parathyroid hormone) in calcium metabolism?

PTH promotes the activation of calcitriol. Signup and view all the answers

What is the function of calcitonin in calcium and phosphate homeostasis?

Calcitonin inhibits the release of PTH from the parathyroid glands. Signup and view all the answers

Which of the following is a symptom of hyperparathyroidism?

Bone loss Signup and view all the answers

What is the abbreviation for ionized calcium?

iCa Signup and view all the answers

Which type of cells are responsible for the synthesis and secretion of PTH?

Parathyroid chief cells Signup and view all the answers

What is the function of osteocytes in bone?

Bone cell communication Signup and view all the answers

Which of the following is a symptom of nutritional secondary hyperparathyroidism in horses?

Muscle weakness Signup and view all the answers

What is the most common cause of idiopathic secondary hyperparathyroidism?

Unknown Signup and view all the answers

What are the classic laboratory findings in horses with hypocalcemia due to low levels of PTH?

Low total calcium and high ionized calcium Signup and view all the answers

What is the primary cause of nutritional secondary hyperparathyroidism in reptiles and amphibians?

Deficiency of dietary calcium Signup and view all the answers

What is the condition known as 'big-head disease' in horses?

Nutritional secondary hyperparathyroidism Signup and view all the answers

What is the main factor implicated in the development of nutritional secondary hyperparathyroidism in reptiles and amphibians?

Imbalance of calcium-phosphorus ratio Signup and view all the answers

What is the main cause of skeletal deformities and bone effects in patients with secondary hyperparathyroidism?

Excessive mobilization of calcium from the skeleton Signup and view all the answers

What are the classic laboratory findings in horses with secondary hyperparathyroidism?

Low total and ionized calcium Signup and view all the answers

What is the role of parathyroid hormone in the development of nutritional secondary hyperparathyroidism?

Excessive production of PTH Signup and view all the answers