Biology 2004 JAMB Past Questions - Question 31: The two key cations involved in the action potential of nervous transmissions are

Correct Answer

C

Explanation

C - Sodium ions are located outside the axon while potassium ions arefound inside the axon making the axon to have potential difference or becomepolarised. Once an impulse reaches.a portion of the axon (nerve fibre) actionpotential is set up. That is the sodium and potassium gates or.channels on theaxon membrane widen to enable the ions to move in either direction. Once anaction potential is set up in a portion of the axon, it stimulates the adjacentaxon and in this manner an electrical impulse is passed along the fibre. Ironis needed for haemoglobin production in the red blood cells. Magnesium is amajor component of bones and activates glycolytic enzymes in the muscles