How to write a nursing essay on Chemical Neurotransmission (Solved)

How to write a nursing essay on Chemical Neurotransmission (Solved)

Neurons are essentially electric devices that allow the flow of ions in and out of the cell leading to communication. Neurons communicate with each other using electrical signals called action potentials and chemical neurotransmitters. An action potential represents rapid changes in the voltage caused by the flow of certain ions into and out of the neuron (Fletcher, 2022). When an action potential arrives, neurotransmitters are immediately released from the terminal into the synaptic cleft where communication occurs. The generation of an action potential can be explained in various stages as described below.

The resting membrane potential represents the balance that exists between the intracellular and extracellular matrices of the cell. For neurons, the resting potential sits between -50 and -75 mV (Jabeen & Thirumalai., 2018). In the neuron, K+ ions are in greater concentration on the inside than Na+ and Cl- ions which have a greater concentration on the outside of the cell. A balance between these ions exists to maintain the resting membrane potential. During the generation of the action potential, voltage-gated Na channels open as a result of an electrical stimulus. Action potentials only occur if a threshold is reached as the ions move in and outside of the cell (Fletcher, 2022). When a threshold is reached, a response of the same magnitude is elicited irrespective of the stimulus strength. The initiation phase of the action potential only lasts for 1 msec and the voltage-gated Na+ channels begin to close.

The second phase is called repolarization and it begins with the opening of the voltage-gated K+ channels. The K+ channels are much slower than the Na+ channels making the opening of the K+ coincidental with the inactivation of the Na+ channels. The positive potential inside the cells causes the K+ channels to open and the ions move down their electrochemical gradient out of the neuron (Fletcher, 2022). The movement of the K+ ions out of the cell makes the membrane potential negative and it starts to approach its initial resting potential. Because there are differences in the movement of the Na+ and K+ ions into and out of the cell, the K+ channels often remain open slightly longer than needed (Jabeen & Thirumalai., 2018). This opening overshoots the normal resting potential leading to hyperpolarization.

Although some cells communicate information through electric signals generated via action potentials, most cells communicate via chemical synapses. First, the neurotransmitter is synthesized and stored in vesicles. When an action potential arrives at the nerve ending, the neurotransmitter is released from the terminal into the synaptic cleft (Jabeen & Thirumalai., 2018). Selective receptors on the postsynaptic cell recognize the neurotransmitter and it is passed to generate another action potential. After the action potential is generated, the neurotransmitter is inactivated to prevent constant stimulation of the cells (Jabeen & Thirumalai., 2018). Overall, neurons communicate with each other using action potentials and the release of neurotransmitters from one end can either excite or inhibit the other neuron from firing an action potential.

Drug’s Half-Life

A drug’s half-life is one of the key concepts used to explain the mechanism of drug disappearance from the body. A medication’s half-life refers to how long it takes for half of the dose to be metabolized and eliminated from the body (Smith et al., 2018) The half-life of drugs varies among individuals because of patient-specific and drug-related factors. For example, patients with kidney diseases will take long to clear drugs from the system making their half-lives prolonged. Overall, the drug’s half-life varies from a few hours to a few days or even weeks. The drug’s half-life is used to dictate the dosing regimen and establish periods when peak concentrations are achieved (Smith et al., 2018). For example, if the half-life of a drug is too short, it may require frequent dosing to maintain desired exposures.


Fletcher, A. (2022). Action potential: Generation and propagation. Anaesthesia & Intensive Care Medicine12(6), 258-262.

Jabeen, S., & Thirumalai, V. (2018). The interplay between electrical and chemical synaptogenesis. Journal of Neurophysiology120(4), 1914-1922.

Smith, D. A., Beaumont, K., Maurer, T. S., & Di, L. (2018). Relevance of half-life in drug design. Journal of Medicinal Chemistry61(10), 4273–4282.

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