3. The calcium levels in the blood and bones are being controlled and regulated by the parathyroid glands. Parathyroid glands are next to and sometimes inside the thyroid glands. Parathyroid glands are small glands in the endocrine system that control how much calcium is inside our bones, which affects how much calcium is in our blood. Calcium control is important because it lets the normal conduction of electric currents to run in our nerves and is also, the main element that causes our muscles to contract. The muscles contract when the brain signals and the body will pull calcium from the blood into the muscle cells. The calcium will then bind with the troponin, a complex of three regulatory proteins important to muscle contraction, which then draws it …show more content…
When the calcium disappears, the troponin and tropomyosin return to position, the myosin and actin detach, and the filaments glide apart to loosen the muscle. Going back to the parathyroid glands, there are four glands and have very rich blood supply. Rich blood supply is good since they are obliged to observe the calcium level in the blood 24 hours a day. When the parathyroid glands have blood filtering, they expose the amount of calcium existing in the blood and behave by producing more or less parathyroid hormone (PTH). PTH is released to regulate calcium levels in a body. When the calcium level in the blood is scarce, the cells of the parathyroids sense this and produce additional parathyroid hormone. When the parathyroid hormone is freed into the blood, it flows to act in a number of places in order to enlarge the amount of calcium in the blood. When the calcium level in the blood is too excessive, the cells of the parathyroids produce less parathyroid hormone or stop completely, which allows the calcium levels to