Parathyroid hormone (PTH) is the primary hormone responsible for maintaining blood calcium levels. One of its major actions is on bone, where it stimulates bone resorption—the breakdown of bone tissue to release calcium and phosphate into the bloodstream. PTH binds to receptors on osteoblasts (bone-forming cells), which in turn release factors that stimulate osteoclasts (bone-resorbing cells) to increase their activity. The osteoclasts dissolve the mineralized bone matrix, releasing calcium and phosphate. While this weakens bone over time, it is a crucial rapid-response mechanism to correct hypocalcemia. PTH also has anabolic effects on bone when administered intermittently at low doses (used therapeutically for osteoporosis). However, its primary physiological effect in response to low calcium is to increase bone resorption.

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Zambia

• Joseph Soko – 101 pts

• Visual Pathway Lesions
• Positive and Negative Symptoms
• Hallucinations and Delusions
• Antipsychotic Medications
• Emergency: Environmental Emergencies