Calcium Homeostasis and Regulation

📋 Course Outline

1. Calcium functions and body distribution
2. Calcium pools and bone exchange dynamics
3. Calcium regulation by PTH, calcitriol and calcitonin
4. Vitamin D metabolism and activation steps
5. Phosphate regulation and renal handling
6. Parathyroid gland structure and PTH secretion control
7. Calcitonin and PTHrP roles in calcium homeostasis
8. Calcium homeostasis in birds and long-term deficits
9. Hypocalcaemia clinical cases and treatment
10. Calcium disorders and urolithiasis mechanisms

📖 1. Calcium functions and body distribution

🔑 Key Concepts & Definitions

• Calcium : Calcium is an essential ion used for muscle contraction, neuronal activity, exocytosis, coagulation, cell communication, and bone structure.
• Hydroxyapatite crystals : Hydroxyapatite crystals are bone mineral made of calcium, phosphate, and water that provide structural integrity.
• Intracellular calcium : Intracellular calcium is the pool inside cells, typically bound to proteins or stored in organelles like mitochondria and ER.
• Extracellular fluid calcium pool : The extracellular fluid (ECF) calcium pool controls blood calcium levels and supports rapid regulation.
• Blood calcium forms : Blood calcium exists in three forms: protein-bound, anion-complexed, and free ionised Ca2+.

📝 Essential Points