Calcium Calcium Calcium is a chemical element with symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The
N-type calcium channel when binding to the receptors, can inhibit the release of the pro-nociceptive neurotransmitters and neuromodulators that come from the central nerve terminals of the afferent neurons. This inhibition is what ultimately can stop the transmission of pain to the person from damaged cells. Ziconotide is an inorganic version of the ɷɷ-conotoxin, MVIIA. This medicine is able to inhibit the release of pro-nociceptive receptors, which will then block the transmission of pain. N-type calcium channel N-type calcium channels are voltage gated calcium channels that are distributed throughout the entire body. These channels are high voltage activated channels composed of alpha-1B subunits.