Calcium

Definition

Calcium is a chemical element with the symbol Ca and atomic number 20. It is an essential mineral that plays a crucial role in the structure and function of the human body, particularly in the development and maintenance of bones and teeth, as well as in various physiological processes.

5 Must Know Facts For Your Next Test

1. Calcium is the fifth most abundant element in the human body, with the majority (99%) found in the bones and teeth.
2. Calcium is essential for the development and maintenance of strong bones and teeth, as it is a key structural component.
3. Calcium plays a crucial role in muscle contraction, nerve function, and blood clotting, among other physiological processes.
4. The body regulates calcium levels through the actions of parathyroid hormone (PTH) and vitamin D, which work to maintain calcium homeostasis.
5. Inadequate calcium intake can lead to conditions such as osteoporosis, where the bones become weak and brittle, increasing the risk of fractures.

Review Questions

• Describe the role of calcium in the structure and function of bones and teeth.
  • Calcium is a critical structural component of bones and teeth, making up the majority of their mineral content. In bones, calcium, along with other minerals, forms the hard, dense matrix that provides strength and rigidity. In teeth, calcium is a key component of the enamel, the hard outer layer that protects the tooth. Calcium is also essential for the ongoing remodeling and repair of bones and teeth, as it is required for the mineralization process that reinforces their structure.
• Explain how the body regulates calcium homeostasis and the involvement of parathyroid hormone (PTH).
  • The body tightly regulates calcium levels through a complex system involving the parathyroid glands and the hormone they produce, parathyroid hormone (PTH). PTH acts to maintain calcium homeostasis by stimulating the release of calcium from the bones, increasing calcium absorption in the intestines, and promoting the reabsorption of calcium in the kidneys. This helps to keep calcium levels within a narrow range, as both high and low calcium levels can have detrimental effects on the body's functions.
• Analyze the potential consequences of inadequate calcium intake and how it can lead to conditions such as osteoporosis.
  • Insufficient calcium intake, especially over an extended period, can lead to the development of osteoporosis, a condition characterized by the loss of bone mass and density. Without adequate calcium, the body cannot maintain the proper structure and strength of bones, making them more susceptible to fractures. This is particularly concerning for older adults, as bone loss naturally occurs with age. Preventing osteoporosis through a diet rich in calcium, along with weight-bearing exercise and vitamin D supplementation, is crucial for maintaining bone health and reducing the risk of debilitating fractures.

Related terms

Calcium Ion (Ca2+): The ionic form of calcium, which is the primary form in which calcium is transported and utilized in the body.

Calcium Carbonate: A calcium salt commonly used as a dietary supplement and in the production of antacids, toothpaste, and other products.

Parathyroid Hormone (PTH): A hormone produced by the parathyroid glands that regulates calcium homeostasis in the body.