Final answer:
Total plasma calcium is essential for bodily functions like muscle contraction, enzyme activity, and blood coagulation. Calcium homeostasis ensures a balance of approximately 9.5-10.5 mg/100 ml of calcium in the blood, regulated by hormones and bodily systems. Both hypo- and hypercalcemia can have serious physiological consequences.
Step-by-step explanation:
Importance of Total Plasma Calcium
Total plasma calcium is crucial because it plays vital roles in muscle contraction, enzyme activity, blood coagulation, and various other physiological processes. Total plasma calcium exists in three forms within the body: ionized, non-diffusible (protein-bound), and complexed (with organic acids, phosphate, citrate, etc.). The regulation of calcium within the blood, known as calcium homeostasis, is essential as the body must maintain adequate levels of calcium to function correctly.
Hypocalcemia, or low levels of calcium in the blood, can lead to issues such as tetany, blood clotting disorders, muscle spasms, and neurological problems. Conversely, hypercalcemia, or high levels of calcium, can cause lethargy, confusion, and even coma. Factors such as plasma proteins, plasma phosphate, metabolism, and parathyroid hormone influence the level of blood calcium, thus affecting overall health.
The body constantly balances calcium levels through interactions between the skeleton, digestive, and urinary systems, under the control of hormones such as parathyroid hormone (PTH), vitamin D, and calcitonin. Given the dynamic and reciprocal relationships between these systems and compounds, maintaining a normal calcium level of about 9.5-10.5 mg/100 ml is significant for healthy body function.