Resorption

Definition

Resorption is the process by which substances, such as bone minerals and organic components, are removed from the bone matrix and dissolved into the bloodstream. This process plays a vital role in maintaining calcium homeostasis and bone remodeling, allowing the body to adapt to changing metabolic needs and repair damaged bones.

5 Must Know Facts For Your Next Test

1. Resorption is essential for the release of calcium into the bloodstream, helping to maintain normal physiological functions and prevent hypocalcemia.
2. The activity of osteoclasts is a key factor in the regulation of resorption; increased osteoclast activity leads to enhanced bone resorption and a decrease in bone density.
3. Hormones like parathyroid hormone (PTH) and calcitriol stimulate bone resorption by increasing osteoclast activity, while calcitonin can inhibit it.
4. In conditions like osteoporosis, there is an imbalance between bone resorption and formation, leading to weakened bones and increased fracture risk.
5. Medications such as bisphosphonates are used to inhibit osteoclast activity, reducing excessive bone resorption in diseases that affect bone density.

Review Questions

• How does resorption contribute to calcium homeostasis in the body?
  • Resorption plays a crucial role in calcium homeostasis by facilitating the release of calcium from the bones into the bloodstream when needed. When blood calcium levels drop, hormones like parathyroid hormone stimulate osteoclasts to increase bone resorption. This process ensures that adequate calcium is available for essential functions such as muscle contraction and nerve signaling.
• Discuss the impact of hormonal regulation on the process of resorption in bone metabolism.
  • Hormonal regulation significantly influences bone resorption through various mechanisms. Parathyroid hormone (PTH) increases osteoclast activity, promoting greater resorption to elevate blood calcium levels. Conversely, calcitonin inhibits osteoclast function, reducing resorption when calcium levels are adequate. This balance maintained by hormones is critical for healthy bone metabolism and overall mineral homeostasis.
• Evaluate the consequences of excessive resorption on skeletal health and discuss potential therapeutic interventions.
  • Excessive resorption can lead to conditions like osteoporosis, where bone density decreases, increasing fracture risk. This imbalance often arises from factors such as hormonal changes or certain medications. Therapeutic interventions, such as bisphosphonates or hormone replacement therapy, aim to inhibit excessive osteoclast activity, restore balance between bone resorption and formation, and improve overall skeletal health.

Related terms

Osteoclasts: Specialized cells responsible for bone resorption, breaking down bone tissue to release minerals and collagen into the bloodstream.

Calcium homeostasis: The regulation of calcium levels in the body, which is critical for various physiological processes including muscle contraction, nerve function, and blood clotting.

Bone remodeling: The continuous process of bone resorption and formation that helps maintain bone strength and mineral balance throughout life.