Homeostasis: An Analysis of Energy

Homeostasis: An Analysis of Energy Homeostasis in the Body

The ability of the human body to maintain a homeostatic state at any point in time depends on a number of factors. Homeostasis generally refers to the ability of an organism, including a human to maintain a certain state of equilibrium. This is achieved through minute physiological processes that occur on a day-to-day basis (Cone, 2001). There are some studies which suggest that energy is stored in the body as a mechanism for adjusting or re-establishing a state of homeostasis in the body, which may or may not be a predetermined state based on genetics and other individual factors (Schwartz, Woods, Seeley, Barsh, Baskin & Leibel, 2003). The subject of energy homeostasis with regard to human physiology is discussed in greater detail below.

Literature Review: Energy Homeostasis

Energy homeostasis can be defined as the state of equilibrium where the body is not only producing an adequate level of energy to function, but where the metabolism is working synergistically with the rest of the body to burn and store nutrients as needed (Cone, 2001). This is an ongoing process that occurs as human beings feed and hydrate themselves day in and out. Energy homeostasis is affected by a number of factors, including how much exercise and how much sleep one gets during the course of a given day (Cone, 2001). If for example a person sleeps excessively, in theory they will disrupt the natural state of equilibrium in the body, potentially causing even more sleepiness (contrary to what one might think, that an individual might feel more rested).

Cone (2001) cites physiological experiments conducted that show that energy stored in fat tissue is actually "homeostatically controlled by the hypothalamus" and notes that the brain adjusts for excess fat and attempts to establish homeostasis in the body by adjusting metabolism and hunger, which in theory will drive someone back to a preset weight (p. 565). Using the same theory one can conclude that the body will make adjustments when someone loses too much weight in order to re-establish a homeostatically comfortable state. That state at which someone is physiologically in homeostasis seems to be at least in some respects genetically controlled (Cone, 2001). There is research being conducted to determine whether or not one can alter the state in which the body is predisposed to 'maintain' (Schwartz, Woods, Seeley, Barsh, Baskin & Leibel, 2003).

In a similar study conducted by Schwartz, Woods, Seeley, Barsh, Baskin & Leibel (2003) the idea that energy homeostasis is "inherently biased toward weight gain" is explored. The researchers attempt to describe a model of energy homeostasis that explains neural pathways utilized to control energy balance. The authors suggest that individuals who lose weight will constantly have to attempt to maintain their weight loss over time, as the body sees losing weight in some situations as an attempt to disrupt the natural homeostasis of the body. This is particularly true of individuals whose weight loss results in a weight that is considered far less than their average or 'normal' weight. The authors argue from a physiological perspective that it is much easier for the body to produce a physiologically homeostatic state that is based on a heavier than a lighter weight.

Badman & Flier (2005) in their work find that the intestine and associated visceral organs are critical players in energy homeostasis. The authors suggest that "the gut, pancreatic islets of Langerhans, portal vasculature and visceral adipose tissue" all communicate with portions of the brain responsible for energy balance, via neural and endocrine pathways. The central nervous system is responsible for interpreting the signals sent by these organs, which are meant to reflect energy stores, the recent nutritional status of a person and other factors related to energy metabolism. Further the authors point out that parts of the central nervous system including sections of the hypothalamus then coordinate energy intake and expenditure. The authors suggest that manipulation of any of these components may be an avenue for obesity research. Like the previous researchers discussed, the authors suggest that the homeostasis of the body can be manipulated both intentionally and un-intentionally by individual's lifestyle and personal behaviors.

In fact all organs of the body work synergistically to promote homeostasis. As Westerterp, Plasqui & Goris (2005) note water is vital to energy homeostasis and is directly impacted by factors including physical activity and water loss due to temperature. The authors conducted a study of forty-two women and ten men measuring their water intake, physical activity level and the season. They found that women were more likely to exhibit higher water turnover regardless of physical activity and season, but also showed that it was essential for humans to normalize water loss in order to compensate for energy expenditure and maintain a state of homeostasis. Thus from their research one can conclude that men and women may require different levels of basic nutrients in order to maintain a state of homeostasis. Also important to this study is the notation that water like other nutrients is a vital component for maintaining the physiology of the human body.

Summary

From the research provided above one may conclude that homeostasis is a state that is maintained through a complex process involving all of the body's major organs and systems. No one aspect of physiological functioning is more important than another when it comes to the homeostatic condition of the body.