Essay on Homeostasis

Homeostasis is the tendency to maintain a stable and relatively constant internal environment. It is crucial for any living thing to maintain a stable internal condition since it must always remain constant. Despite the external environment’s dynamicity, the body employs different physiological strategies that support the system’s proper function. This capability is one of the crucial aspects that enable the human body to stay alive. The body acts upon and resists the effects of external factors to prevent its deviation from the state of balance, equilibrium, and stability it favors rather than doing nothing. According to Modell et al. (2015), three general components enable the human body to maintain homeostasis. They include the receptor, control, and effector centers.

Maintaining homeostasis

The hemostasis mechanism is in the form of a loop that can either be positive or negative. Positive feedback propels the situation and results in more stimulation, whereas negative feedback decelerates the process and inhibits the stimulus (Castanho & Dos Anjos Garnes, 2019). For example, a high body temperature triggers the negative loop, which returns it towards the set point. The sensors, which are primary nerve cells with endings in the brain, will detect the high temperature and relay it to the temperature-regulatory control center. Processing this information will take part in the control center, and effectors such as sweat glands will be activated (Modell et al., 2015). The function of these effectors is to lower the body temperature by opposing the stimulus.

The body temperature does not always go above the setpoint. In some situations, it can go below the set point. In general, there are at least two negative feedback loops that are usually involved in the homeostatic circuit. The first negative feedback loop is designed to lower a parameter after it has gone above the setpoint (Modell et al., 2015). The second negative feedback loop is intended to return the parameter up when it is below the set point.

For example, when the external body temperature is either too cold or too hot, the hypothalamus, the temperature regulatory center in the brain, is notified by the sensors in the periphery that the temperature has strayed from the setpoint (Tansey et al., 2015). For instance, when an individual has been exercising too hard, the internal body temperature rises above the setpoints, and cooling it down will require activating the necessary mechanisms (Library, 2019). The increase in blood flow in the skin seeks to increase heat loss to the surrounding. Sweating is also a mechanism that allows the body to cool off when the sweat evaporates.

The temperature center in the brain will also trigger responses to keep warm when an individual is sitting in a cold room and is not dressed warmly. Tansey et al. (2015) note that a person may begin shivering since the blood flow in the skin decreases. This action allows the body to generate more heat. The skin may also develop goosebumps, allowing the body hair to stand up and trap air near the skin.

The negative feedback loops play a fundamental factor in homeostasis, and any interference with this feedback mechanism disrupts homeostasis and may eventually result in disease. For example, a broken feedback loop involving insulin hormone results in diabetes disease (Röder et al., 2016). The human body finds it challenging to lower high blood sugar levels when the feedback loop is broken. When an individual consumes a meal, the blood glucose levels increase, triggering the β cells in the pancreas to secrete insulin (Library, 2019). It then activates body cells to absorb this glucose for energy. Insulin is also responsible for the conversion of glucose to glycogen in the liver. These processes are responsible for reducing glucose levels in the blood, which returns the system to homeostasis.

On the other hand, glucagon increases glucose concentration in the blood. When the blood glucose levels are low, the pancreatic α cells release glucagon, which initiates the breakdown of glycogen to glucose in the liver (Röder et al., 2016). This increases the glucose level in the body. The system is brought back to homeostasis when glucagon secretion is reduced. Therefore, diabetes occurs when the human body stops responding to insulin or when the pancreas fails to produce enough insulin. Therefore, blood sugar remains high under these conditions since the body cells cannot absorb glucose readily.

Ecosystem homeostasis

Ecosystems comprise a network of animals from the tiniest insects to the largest mammals, alongside various microorganisms, fungi, and plants, making the ecosystem complex. There is an interaction between all these lifeforms since caterpillars will feed on leaves, bears prey on fish, while shrews eat insects. A delicate balance is maintained by everything that exists in nature, and scientists refer to the balance of organisms in an ecosystem as ecosystem homeostasis (Zakharov et al., 2018). The fundamental goal of ecosystem homeostasis is equilibrium. But nothing is ever perfectly balanced in the real-world ecosystem. Various animal species have their population at a similar range, resulting in a relatively stable state of an ecosystem in equilibrium (Ecological Center, 2021). Therefore, as long as there is no general downward or upward trend, populations can go up and down in cycles.

Negative feedback in ecosystem homeostasis operates more diffusely than physiology due to the decentralized nature of ecological systems such as communities, populations, and ecosystems. The interactions among species, individuals, and their environment result in negative feedback since a central processing unit that implements and coordinates negative feedback is unavailable (Ecological Center, 2021). A classic example of how negative feedback could stabilize the system due to consumer or resource dynamics is the interaction between predators and prey. There is an increase in resource availability for the predators when the prey population increases. This increase results in increased survival and reproduction rates for the predator due to the consumption of the prey. Hence, the predator population increases. However, an increase in predator population increases the demand for prey, increasing the predators’ death rates. This is due to the decline in the prey population, which cannot support the high predator abundance. Eventually, the predator population also reduces. Therefore, the limiting resource of the prey induces negative feedback, which counteracts the initial increase in predator abundance.

Many systems experience such a case, and there is a strong stabilizing constraint on the community’s dynamic when food resources are limiting. An increase in resource consumption results in a decrease in other components since the resources are limited. The Ecological Center (2021) defines compensatory dynamics or species compensation as the balance between increased and decreased species. The negative feedback that counteracts the increased consumption rates by various communities emerges from the finite nature of these resources. Resources are responsible for reproduction, growth, maintenance, and survival and as a result, limiting them affects net production, birth, and death rates. Therefore, resource constraints are essential for stabilizing the overall consumption and stabilizing critical ecosystem properties such as biomass production, total abundance, and standing biomass.

In conclusion, people have been steadily growing, particularly since the industrial revolution. It took several years for the human population to reach one billion, and the world is now swiftly approaching eight billion, more than three hundred years later. This sounds like the world is on its way to a catastrophe due to overpopulation. However, due to decreased birth rates resulting from increasing access to contraception and women’s education, the world’s population is not predicted to grow exponentially. The average family size in countries where women are empowered is tiny, with very few children. An increase in natural and economic resource demand and competitiveness has led to reduced birth rates, leading to a drop in the world population.

References

Castanho, F. L., & Dos Anjos Garnes, S. (2019). Homeostasis: An Integrated Vision. IntechOpen. https://books.google.co.ke/books?id=y7-QDwAAQBAJ

Ecological Center. (2021). Maintenance of Homeostasis in Ecological Systems – Population Dynamics. https://www.ecologycenter.us/population-dynamics-2/maintenance-of-homeostasis-in-ecological-systems.html

Library, T. O. T. O. C. (2019). The Animal Body – Basic Form and Function: Biology. Independently Published. https://books.google.co.ke/books?id=IPNMzQEACAAJ

Modell, H., Cliff, W., Michael, J., McFarland, J., Pat Wenderoth, M., & Wright, A. (2015). A Personal View A physiologist’s view of homeostasis. Adv Physiol Educ, 39, 259–266. https://doi.org/10.1152/advan.00107.2015.-Homeostasis

Röder, P. V., Wu, B., Liu, Y., & Han, W. (2016). Pancreatic regulation of glucose homeostasis. Experimental & Molecular Medicine, 48(November 2015), e219. https://doi.org/10.1038/emm.2016.6

Tansey, E. A., Johnson, C. D., & Johnson, C. D. (2015). Staying Current Recent advances in thermoregulation. Adv Physiol Educ, 39, 139–148. https://doi.org/10.1152/advan.00126.2014.-Ther

Zakharov, V., Minin, A., & Trofimov, I. (2018). Study of developmental homeostasis: From population developmental biology and the health of environment concept to the sustainable development concept. Russian Journal of Developmental Biology, 49(1). https://doi.org/10.1134/S1062360418010071