Fluid Balance In Human Organisms Sample College Essay

Evolutionarily, human organisms developed well-controlled regulatory mechanisms that maintain fluid balance because water is an essential medium for all biochemical reactions in the body. Indeed, specific hormones and signaling molecules, like aldosterone, cortisol, and antidiuretic hormone, are known to regulate water-salt balance in the body by promoting or stopping diuresis and thirst (Rakova et al., 2017). External factors, like salt and sugar intake, can result in fluid retention or excretion, respectively. Furthermore, some pathologies may alter water release, causing edema or dehydration. Endocrine and neural systems maintain the equilibrium between the amount of fluid intake and output, keeping the stability of minerals inside cells and tissues.

The human body loses fluid in sweat and urine, but the balance is controlled by proper water intake, caused by thirst mechanisms. The two primary systems that regulate fluid homeostasis are thirst, initiated or suppressed by neural circuits, and adrenal and hypothalamic hormones that affect kidney function (Gizowski & Bourque, 2018; Rakova et al., 2017). Firstly, thirst is elicited under such circumstances as hypovolemia, hyperosmolarity of plasma, feeding, hyperthermia, and after sleep due to changes in the electrolyte balance in the extracellular space (Gizowski & Bourque, 2018). Coordination occurs in various nuclei in the neocortex, thalamus, and brainstem (Gizowski & Bourque, 2018). Secondly, increased mineral elements in the circulation lead to fluid retention due to elevated aldosterone release from the adrenal glands. Its effect on nephrons is that they start to absorb more water in their tubular network (Rakova et al., 2017). Moreover, aldosterone and cortisol are produced rhythmically under normal conditions, balancing fluid accrual or excretion (Rakova et al., 2017). Overall, the interconnectedness of these two systems plays an essential role in water balance in the organism.

In summary, fluid homeostasis in the human body is attained through tightly controlled endocrine and neural mechanisms. Neural circuits enhance or diminish thirst and subsequent water intake, while adrenal and hypothalamic hormones directly affect kidneys, causing increased or decreased fluid reabsorption. It means that if a person increases one’s salt intake, it may cause tissue edema; however, if mineral and water consumption is moderate, the regulation will be continued rhythmically.


Gizowski, C., & Bourque, C. W. (2018). The neural basis of homeostatic and anticipatory thirst. Nature Reviews Nephrology, 14(1), 11-25. Web.

Rakova, N., Kitada, K., Lerchl, K., Dahlmann, A., Birukov, A., Daub, S., Kopp, C., Pedchenko, T., Zhang, Y., Beck, L., Johanes, B., Marton, A., Müller, D.N., Rauh, M., Luft, F.C., & Titze, J. (2017). Increased salt consumption induces body water conservation and decreases fluid intake. The Journal of Clinical Investigation, 127(5), 1932-1943. Web.

Electric Vehicles And Their Environmental Impact

The pursuit of sustainability and caution toward the environmental impact are characteristics of a developed society. In these terms, combustion engines cause pollution, the effect of which multiplies with the unprecedented spread of automobiles across the globe. Consequently, the pursuit of efficient transportation did not stop with this technology, and humanity has put efforts into the creation of a new vehicle design with an electric engine. Accordingly, a logical question arises whether electric vehicles are, indeed, better for the environment. This essay argues that electric automobiles can become a sustainable alternative to combustion engines, but only as a part of a broader paradigm shift.

The design of an electric vehicle is perceived as inherently cleaner that a combustion engine. The latter remains responsible for immense air pollution that continues to threaten the population of the world. Since the widespread of combustion engines began, global authorities have continuously implemented new, higher standards of controlled emissions with an aim to prevent the situation from deteriorating. However, Carvalho (2019) argues that these advances did not suffice to instil lasting improvements in terms of air pollution. A report by the European Environmental Agency indicates that the number of air pollution-related deaths in Europe exceeded 500,000 in 2015 (Carvalho, 2019). Furthermore, the death rate correlated positively with the number of vehicles in operation for each specific country. This data suggests that traditional combustion-engine cars play a key part in the continuous air pollution that poses major risks for the public health. A wider use of electric vehicles is expected to improve the situation by mitigating the strong impact of the growing number of automobiles in operation.

Logically, many developed counties attempt to promote their use or even plan to ban combustion engines by a certain point. For example, this is the case of China that acknowledged the increasing impact of vehicles on the quality of life in Shanghai. According to Alimujiang and Jiang (2020), this initiative included public transport that accounted for a large part of the pollution, being a key enabler of economic growth. The transition toward electric taxis and buses in Shanghai led to an observable decrease of “CO, NOx, NMHC, and PM10 emissions” (Alimujiang & Jiang, 2020, p. 181). Furthermore, electric vehicles yield economic benefits for consumers, as well. Combustion engines need regular refueling, which can be costly with the continuous increase of gasoline prices. Costa et al. (2021) state that electric vehicle owners are freed of these expenses, which is why such cars become economically beneficial after a certain point. The exact profitability threshold varies across different countries: from 2,500 km in Portugal to 335,000 km in Czech Republic (Costa et al., 2021). Ultimately, the owners of electric automobiles see economic improvements along with better health and quality of life.

On the other hand, in spite of the objective advantages, electric vehicles remain a small part of the total automobile market due to the lack of public trust. Ellsmoor (2019) the criticism of such cars appeared simultaneously with their development in the early 2000s. It is argued that the proponents of electric transportation focus on the immediate impact of a single automobile in operation, whereas a broader context needs to be examined. Each electric vehicle needs a battery and a constant supply of electricity, and the production of both can be extremely damaging to the environment. However, a lot depends of the manufacturer’s technology in this regard. Ellsmore (2017) notes that battery production in Europe is cleaner than in China, meaning that it is technologically feasible to make the industry greener that internal combustion vehicle manufacturing. In terms of the energy supply, an accelerated transition toward sustainable energy sources will alleviate the issue, as well (Hawkins et al., 2012). Indeed, it is unwise to view the matter on the level of a single electric vehicle in operation. Instead, a broader context needs to be considered to cause a full paradigm shift.

Nevertheless, the aforementioned paradigm shift does not appear impossible, as it corresponds with the global policy of sustainability across different industries. The development of cleaner, renewable energy sources is another key part of the global agenda, meaning that these efforts will eventually synergize with the spread of electric vehicles. However, while green initiatives are of paramount importance, the economic aspect cannot be neglected. The study by Costa et al. (2021) shows that electric vehicles have a certain profitability threshold, but it does not eliminate the fact that such cars are more expensive, in general. For an average consumer, the necessity to pay a higher amount at once is likely to outweigh distant benefits of the ownership. The required sum may not be available at all at the specific moment, prompting the purchase of an older combustion-engine car. Additionally, the profitability threshold varies greatly from short 2500 km in Portugal to considerable 335,000 km in Czech Republic (Costa et al., 2021). Thus, the situation contains many local variables that need to be considered for the effective promotion and use of electric cars. Zhao et al. (2020) concur, adding that the profound analysis is required even at the level of a separate city. Otherwise, the investigation of electric car use, impact, and profitability will be too generalized to contribute to the paradigm shift.

Ultimately, the development of electric vehicles addresses global communities’ pressing concerns regarding air pollution and environmental impact of the automobile industry. These factors account for hundreds of thousands of premature deaths annually, and the new vehicle design serves to mitigate the problem. In addition, electric cars are economical, too, helping their owners avoid the increasing prices of gasoline. However, their opponents refer to a broader context of energy and batter production impact with questionable economic benefits in some areas. These concerns appear reasonable, as they highlight objective flaws of the electric vehicle design. Nevertheless, the benefits prevail, and the use of electric vehicles is likely to become the future of transportation, as long as broader context is considered for a quality paradigm shift.


Alimujiang, A., & Jiang, P. (2020). Synergy and co-benefits of reducing CO2 and air pollutant emissions by promoting electric vehicles—A case of Shanghai. Energy for Sustainable Development, 55, 181–189. Web.

Carvalho, H. (2019). Air pollution-related deaths in Europe – Time for action. Journal of Global Health, 9(2). Web.

Costa, C. M., Barbosa, J. C., Castro, H., Goncalves, R., & Lancerons-Mendez, S. (2021). Electric vehicles: To what extent are environmentally friendly and cost effective? – Comparative study by European countries. Renewable and Sustainable Energy Reviews, 151, 111548. Web.

Ellsmoor, J. (2019). Are electric vehicles really better for the environment? Forbes. Web.

Hawkins, T. R., Gausen, O. M., & Strømman, A. H. (2012). Environmental impacts of hybrid and electric vehicles — A review. The International Journal of Life Cycle Assessment, 17, 997–1014. Web.

Zhao, X., Ye, Y., Ma, J., Shi, P., & Chen, H. (2020). Construction of electric vehicle driving cycle for studying electric vehicle energy consumption and equivalent emissions. Environmental Science and Pollution Research, 27, 37395–37409. Web.

Dual Store Model Of Memory

Responding to the dual store model of memory, the model of human memory has three main components; sensory registers, working memory, also known as short term memory, and long-term memory (LTM). The model shows that information enters the sensory registers even when the person is not mentally active and stays there for about ¼ and ½ seconds, waiting for processing (Radvansky, 2021). The capacity of this component entails all the sensory experience with an encoding that is specific for every type of sense. The information received in this register involves the five senses, including touch, visual information, and sound (Radvansky, 2021).

Its storage capacity is large but with a short duration, making the information stored get lost through decay. The sensory register receives information constantly; however, most of the information is not given attention and therefore remains in the sensory registers for a short period.

When the individual gives attention to the information in the sensory register, the information instantly moves to the working memory. The working memory is the component where individual thinking takes place (Radvansky, 2021). The components store and process information from both the sensory register and the long-term memory. Short-term memory is significant in the interpretation of the information received from the environment. Furthermore, working memory is vital in monitoring and controlling information use and flow all over the memory system.

The short-term memory has a storage duration of about 30 seconds, with a capacity ranging from 5 to 9 chunks. Information stored in the working memory is lost either through decay or displacement. Therefore, it is necessary to keep rehearsing either mentally or verbally to ensure that the stored information exceeds thirty seconds (Radvansky, 2021). For example, maintenance rehearsal enables one to remember phone numbers for a required time when making a call. This shows that in this type of rehearsal, it is not necessary to know the meaning of the information (Radvansky, 2021). Therefore, continuous rehearsal allows the information to be stored for a more extended period when moving the information to the long-term memory.

Information from the working memory to the Long-term memory requires further processing, which involves a combination of information already stored in the long-term memory and new information. Successfully storing information in long-term memory entails relating information with what an individual already knows (Radvansky, 2021). The capacity and duration of the long-term memory are unlimited. Information stored in the long-term memory can be retrieved to the short-term memory when required. This memory component uses elaborative rehearsal, where stored information is linked with new information (Radvansky, 2021).

Elaborative rehearsal is significant in ensuring information is well coded. For example, when learning the lines in a play, an individual relates the character’s behavior, dialogue, and the personal experience one remembers.

Adding to the discussion post, the discrepancy between the sensory register, working memory, and long-term memory is on the capacity and duration of memory. The sensory registers and the long-term memory have unlimited capacity, while the working memory has a capacity ranging between 5 and 9 units (Radvansky, 2021). The storage duration between the memory components also differs significantly. The information stored in the sensory registers fades fast, followed by the working memory (Radvansky, 2021). Long-term memory storage information fades slowly or can remain permanently depending on the effort of an individual.


Radvansky, G. (2021). Human memory (4th ed.). Routledge.