Explain the significance of sodium,potassium,magnesium,and calcium in biological fluids.

(N/A) Importance of sodium,potassium,magnesium,and calcium in biological fluids:
$(i)$ Sodium $(Na^+)$:
Sodium ions are found primarily in the blood plasma and in the interstitial fluids surrounding the cells.
$(a)$ Sodium ions participate in the transmission of nerve signals.
$(b)$ They help in regulating the flow of water across cell membranes.
$(c)$ They assist in the transport of sugars and amino acids into cells.
$(ii)$ Potassium $(K^+)$:
Potassium ions are found in the highest concentration within the intracellular fluids.
$(a)$ $K^+$ ions activate many enzymes.
$(b)$ They participate in the oxidation of glucose to produce $ATP$.
$(c)$ They are essential for the transmission of nerve signals.
$(iii)$ Magnesium $(Mg^{2+})$ and Calcium $(Ca^{2+})$:
Magnesium and calcium are macro-minerals,indicating their high abundance in the human body.
$(a)$ $Mg^{2+}$ is involved in muscle relaxation and nerve function.
$(b)$ $Mg^{2+}$ is a cofactor for many enzymes and is involved in bone structure.
$(c)$ $Ca^{2+}$ is essential for blood coagulation.
$(d)$ $Ca^{2+}$ plays a critical role in maintaining homeostasis and muscle contraction.