When the level of calcium in the blood drops,

the parathyroid glands secrete a hormone that causes the release of calcium from bone into the blood

one should immediately drink at least two 8 oz glasses of milk

the thyroid gland releases calcium into the blood

the pineal gland releases oxytocin to stimulate the muscles in the absence of calcium

The parathyroid glands secrete a hormone that causes the release of calcium from bone into the blood.

Explanation:

Parathyroid glands have a role to control calcium level in the bloodstream. It is also important, in order to ensure the nervous system, so the body's muscles can work properly and that bones remain strong.

When calcium levels are low, this hormone is released by the parathyroid glands, into the blood, and it causes bones to release calcium and increase the levels in the bloodstream.

If a person doesn't take calcium through their meals, or if they don't have enough vitamin D in their system, calcium level D can be produced by parathyroid hormone.

the answer would be roots! roots are the parts of the plant that are underground, and that's how they'd anchor the plant. the stem is above the sol, which doesn't with anchoring. hope this !