PHGY 210 Lecture Notes - Lecture 3: Jejunum, Duodenum, Hypercalcaemia
11 Feb 2020
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Document Summary
Calcium is a major mineral component of bone. Calcium is important for a number of physiological and cellular functions: it is important for neural excitability for neuromuscular function, it is implicated in release of hormones, neurotransmitters. Experiment: mice with a fundamental defect in calcium absorption mice will eat their bones to maintain normal levels of calcium in the circulation. Calcium is kept in a very narrow physiological range (under homeostatic conditions) in the circulation. In the circulation, 50% of calcium goes around free and 50% is bound to albumin. About 99% of our calcium in our bones (the bones can serve as a reservoir under conditions of inadequate dietary of calcium uptake of calcium to feed cells) Calcium can be obtained in the diet (milk, cheese, eggs, butter ) It is absorbed in the digestive tract primarily in the duodenum and the upper jejunum. The optimal absorption in the intestine requires vitamin d and pth.
