Thyrocalcitonin, which regulates blood calcium, is secreted by the

1. Two glands sit close together in the neck and both influence calcium. 2. The parathyroid glands secrete parathyroid hormone, which raises calcium. 3. The thyroid gland also secretes a protein hormone called thyrocalcitonin. 4. Thyrocalcitonin regulates the blood calcium levels. 5. Attributing TCT to the parathyroid is the trap set by their names and position. _Source: syllabus Biology Ch19 'Chemical Coordination and Integration', section 19.2.4_