AP BIOLOGY

Detailed explanation-1: -Calcium serves many important roles in the human body, including (1) providing structure and hardness to bones and teeth, (2) allowing muscles to contract and nerves to send signals, (3) making blood vessels expand and contract, (4) helping blood to clot, and (5) supporting protein function and hormone regulation.

Detailed explanation-2: -Calcium is a mineral most often associated with healthy bones and teeth, although it also plays an important role in blood clotting, helping muscles to contract, and regulating normal heart rhythms and nerve functions.

Detailed explanation-3: -The only way it can enter the body is through the diet. The bones act as a storage site for calcium: The body deposits calcium in the bones when blood levels get too high, and it releases calcium when blood levels drop too low. This process is regulated by PTH, vitamin D, and calcitonin.

Detailed explanation-4: -Calcium is a mineral your body needs to build and maintain strong bones and to carry out many important functions. Calcium is the most abundant mineral in the body. Almost all calcium in the body is stored in bones and teeth, giving them structure and hardness.

Detailed explanation-5: -Calcium is the major component of the bone, where it is present at more than 99% as calcium-phosphate complexes, and provides the skeleton strength and structure, making the bone a metabolic reservoir to maintain the intra-and extra-cellular calcium pool.