CVS Practice Test 2026 - Free CVS Practice Questions and Study Guide

The ratio of extracellular to intracellular calcium concentration is approximately 14:1. This means that there is a significantly higher concentration of calcium ions in the extracellular fluid compared to the inside of cells.

In a typical resting cell, the intracellular calcium concentration is around 100 nM (nanomolar), while the extracellular calcium concentration is about 1.2 mM (millimolar). When you convert these units and compare the concentrations, it indeed yields a ratio close to 14:1.

This high ratio of extracellular to intracellular calcium is crucial for various cellular functions, including muscle contraction, neurotransmitter release, and many signaling pathways. The large difference in concentration allows calcium ions to rapidly flow into the cells when channels open, triggering these important cellular processes.

The understanding of this ratio is vital for anyone studying physiology, pharmacology, or related fields, as it influences how cells respond to stimuli and manage calcium homeostasis.