Hormone
Hormone
Hormone
Calcitonin
(minimal role)
  • Peptide hormone produced by parafollicular cells of the thyroid gland
  • Secretion stimulated by an increase in serum calcium levels
  • Acts to decrease serum calcium levels when elevated (physiological antagonist to PTH)
  • Bone: Prevents resorption by inhibiting osteoclast activity and stimulating osteoblast activity
  • Kidneys: Weak action to decrease calcium reabsorption