Nerve Signaling

From a young age we are taught to eat a balanced diet full of nutrients which in the body are broken down into individual ions and molecules. Of these ions and molecules, the most important are Calcium (Ca+2), Sodium (Na+), Potassium (K+) and ATP which are primarily derived in from what we eat but also the body synthesizes on its own. Ions play an important role due to their relative electrical charge. These important ions help regulate homeostasis in our bodies, as well as allowing us to move, absorb food, heal, and reproduce. Understanding how these ions work within our bodies will allow us to comprehend the physiology behind muscle contraction, nerve signaling and cell signaling. Upon learning about calcium, we already briefly know how
When looking at the membrane potential, we can see that it is an unequal charge distribution relationship between the slight excess of positive charges outside the plasma membrane compared to the slight excess of negative charges inside. Outside of the plasma membrane is the extracellular fluid that contains high concentrations of sodium and chloride ions, and inside the plasma membrane known as cytosol, contains high concentrations of potassium. Changes in membrane potential results in opening of protein channels which allow these ions to pass freely through the membrane in relation to concentration. Sodium- potassium exchange pumps eject sodium and reclaim potassium in active transport that requires the usage of ATP. When the membrane potential of a pre-synaptic neuron changes, due to different chemical and neurotransmitter stimuli, these ions are released depending on the level of potential happening. “When an action potential starts, the graded potential depolarizes the membrane to a point called threshold potential.”(BOOK) During depolarization, the neurotransmitter is release and opens sodium channels with allows sodium ions to move into the cell. This action triggers the opening of potassium channels, allowing them to move out of the cell. Once the action potential message travels through the axon, it ends its journey at the axon