Parathyroid gland and hormone

Question 1

Parathyroid gland

Answer 1

1. Chief cells/ Principal cells produce parathyroid hormone

2. Oxyphil cell

Question 2

Function of parathyroid hormone

Answer 2

1. Increase number and activity of osteoclasts
   •Increased level of calcium and phosphate released into the blood
2. Kidneys
   • Slows rate at which Ca2+ and Mg2+ are lost from blood into urine
   • Increase Phosphate ions loss in the urine

• Promote Calcitriol formation by kidneys -> active form of vitamin D
-> increases rate of Ca, Phosphate and Mg absorbtion from GI tract

Question 3

Overall effect of parathyroid hormone

Answer 3

1. Increase in blood calcium and magnesium level

2. Decrease in Phosphate ions in the blood

Question 4

Control of calcitonin and parathyroid secretion

Answer 4

1. Higher than normal levels of calcium in the blood
2. Parafollicular cells of the thyroid gland to release calcitonin
3. Lower than normal calcium level
4. Chief cells of parathyroid gland to release more PTH