The effects of alcohol consumption on Homeostasis in various organ systems in the body:
By Sania Hussain
Anglia Ruskin University
Medical Science
30/11/2018
Homeostasis refers to the ‘tendency of a physiological system to maintain itself in balance regardless of the changes taking place in both the internal and external environments.1(Gosling: 192). The role of homeostasis is greatly significant in ensuring the proper function of various body systems such as the endocrine and nervous systems which rely on homeostatic balance to maintain constant internal regulation. These two systems allow for communication amongst organs; for example, the nervous system ensures the rapid transmission of electrical impulses between organ systems – swiftly generating a response. The endocrine system, on the other hand, is made up of glands which produce and secrete hormones directly into the bloodstream, resulting in an overall slower process but longer lasting impact as opposed to the nervous response. Both systems work toward generating the correct response and hence maintaining homeostasis. Excessive alcohol consumption is directly proportional to responses related to altering homeostatic balance, being one of the ‘most serious substance abuse disorders’2 across the world; alcohol consumption is linked to a variety of detrimental health consequences, for example the addition of alcohol to the body leads to inhibition of the pituitary secretion of ADH (anti diuretic hormone). In turn – it is the action of homeostasis which counteracts such a change, stimulating kidney regulation in order to maintain a dynamic equilibrium.3 Alcohol related diseases are growing more prevalent day by day, estimated at up to 18% for males and up to 4% for females4. As such it has become an increasingly alarming problem in society today. Research, conducted in 2012, shows approximately 3.3 million net deaths, were ‘attributable to alcohol consumption’.5 Evidently, as a major contributor to early death, the effects of alcohol on the human body and especially homeostasis are extensive; nonetheless, there is some research to suggest that light to moderate drinking of specific alcohol containing beverages can lower the risk of coronary heart disease6 and stroke7 due to the high polyphenol content.8
The kidney located under and posterior to the liver in the peritoneal cavity9 is directly affected by alcohol consumption, the gross structure of the kidney is made up of the outer cortex and the inner medulla. The role of which is to filter and excrete waste materials such as urea from the blood into the urine. Excessive alcohol consumption not only affects the function of these organs but also the gross structure; animal studies suggest, specifically in dogs, the basement membranes of the glomerulus located in the Bowman's Capsule may become thicker due to cell proliferation10 upon consumption of alcohol. This directly affects the key process of
ultrafiltration within the nephron altering the products in the filtrate as less of the plasma is able to pass through the podocytes and hence creates an excess of certain materials in the blood. This can, for example lead to a buildup of waste products such as urea in the bloodstream creating a homeostatic imbalance. The kidneys carry the homeostatic responsibility of removing harmful substances in the blood passing through. Any change to the system can therefore alter, the functionality of the kidneys making them incapable of controlling and eliminating the waste materials from the blood. For the optimal functioning of the kidney, blood must be maintained within a given pressure to ensure that the filtration takes place effectively; this pressure is maintained by the afferent arteriole where blood enters the nephron and the efferent arteriole where blood leaves the nephron. Alcohol consumption increases the blood pressure, thus affecting the excretion process and exposing the kidney to risky conditions such as hardening and narrowing of arterioles making it harder to get blood to the kidney tissues, this, in turn, makes it harder for the kidneys to filter hormones, ions and waste from the blood. Therefore, leading to further disruptions in maintaining a constant internal environment or homeostasis.11 (Spanagel: 649). If the communication to produce the hormones rectifying the condition of high blood pressure is not provided promptly other organs of the body may collapse. This is due to fact that the functions of the kidneys are also guided by the nervous system, meaning the nervous system gives directions on how to respond to different stimuli. Failure of the nervous system; caused by the caused by excessive alcohol consumption, will end up affecting the functionality of the kidneys hence causing a homeostatic imbalance in the blood.12 (Garban et al: 57).
The kidney is also involved in ensuring that the water potential of the blood is maintained. This is necessary for the transportation of mineral and food substances to other parts of the body; this is because the water makes a large portion of the human blood. Furthermore, the consumption of alcohol directly impacts the mechanism of osmoregulation; ADH production is sensitive to the water potential of the blood, when the concentration of inorganic ions in the blood is above the optimum level the water potential of the blood as well as the tissue fluid becomes more negative; this change is detected by osmoreceptors in the hypothalamus, hence sending a signal to the pituitary gland in the brain which stores ADH (produced in the hypothalamus) to secrete the hormone. The ADH binds to receptors on the cells of the collecting ducts altering the permeability of the tubules of the collecting duct – making the volume of the urine higher and less concentrated or lower and more concentrated. Alcohol consumption suppresses the production of ADH producing large amounts of dilute urine as nerve impulses to the posterior pituitary gland are inhibited hence reducing the reabsorption of water to the collecting duct. This causes homeostatic unrest due to the continuous loss of water from the blood ultimately leading to dehydration.13
Another important function of the water is providing an aqueous environment to facilitate chemical reactions requiring such conditions14 (Fontanelli et al: 49). Alcohol consumption ends
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up dehydrating the body and reducing the water levels in the body. Due to this, the functionality of the kidney is affected, and this can also cause kidney stones. Alcoholism affects the liver of the patient thereby affecting their metabolism function and making the liver unable to excrete ammonia. When this ammonia reaches the kidneys, it can lead to renal failure. The ammonia lowers the blood PH levels and thus can alter some body functions especially enzymatic reaction which prefers other PH levels such as alkaline or neutral conditions15 (Nam et al: 1117). Lowering of the blood PH results in yet again homeostatic imbalance as key processes involved in the breakdown of carbon dioxide become disrupted. Thus, homeostasis ensures more Cl- ions are shifted into red blood cells during the Chloride Shift in order to increase the blood PH. Excessive alcohol consumption can therefore cause homoeostatic imbalance regarding the PH of the blood.
Among the major organs affected by alcohol consumption is the liver. The liver has the function of controlling the blood glucose concentration to ensure that the sugar levels are maintained within the required range. The pancreatic glands within the endocrine system are greatly important in ensuring the stability of blood glucose levels in the body. Insulin and Glucagon are hormones produced by Beta and Alpha cells (respectively), located in the Islets of Langerhans, these hormones are used to control glucose concentrations in the blood. When these concentrations are above the optimum level insulin is produced by the beta cells and secreted directly into the blood stream; where it stimulates hepatocytes from the liver to carry out carbohydrate metabolism. This means that’s the processes of typically glycogenolysis and in extreme cases gluconeogenesis release glucose into the bloodstream bringing the overall blood glucose concentration back to the optimum and maintaining homeostasis. Similarly, when the blood sugar levels are below the required concentration, hepatocytes in the liver trigger glycogenesis – producing more glycogen from glucose in the blood and storing it in the liver.
In addition, after the consumption of alcohol, the liver must break down the alcohol sugar component. The breakdown produces a chemical which destroys the liver cells causing liver cirrhosis16 (Cylwik et al: 450). Liver cirrhosis affects the metabolic functions of the liver, and thus the breakdown of substances such as fats and proteins does not take place effectively. The conditions, therefore, make the body unable to regulate its blood fat levels. The fat gets transported to other body parts such as the heart where it gets deposited and increases the risk of the patient suffering from other cardiac disorders when the liver fails to eliminate excess ammonia in the ornithine cycle of the deamination process. This means that the amino group of the ammonia molecules cannot be removed and processed into urea, leading to not only toxic ammonia build up but also an imbalance in blood urea concentrations – directly disrupting homeostasis. This poses other serious health conditions to the patient17 (Carr: 1091). The liver must perform the process of detoxifying and removing the alcohol from the body as the excess ammonia in the blood gets transported to the brain of the patient, which affects the functioning of the cerebral system. Among the issues the excess ammonia causes to the brain is; increased forgetfulness as well as altering the sleeping habit of an individual. Liver cirrhosis is also associated with other liver conditions such as liver cancer. These condition of the liver
affects the metabolism of fats, carbohydrates and the protein affecting the overall internal balance of the body. Failure in the regulation of blood sugar causes high blood pressure to the patient which can later lead to heart failure18 (Wani et al: 121). Heavy drinking is also associated with Hepatitis of the liver which leads to the inflammation of the liver and thus injury to the liver19 (Thakkar et al: 299). The damage caused to the liver by Hepatitis, therefore, alters the functionality of the liver regarding creating a homeostatic balance which can lead to other further complications and even death to the victim.
Excessive intake of alcohol lowers the blood sugar levels below the maximum requirements. When this happens at late stages of liver cirrhosis, for instance, the body cannot be able to coordinate to have its blood sugar levels rectified. The patient, therefore, is forced to use unnatural means such as undergoing through medication, such as insulin injections, to ensure that the blood sugar levels are maintained. Another manner through which alcohol affects the blood sugar is through increasing the appetite of the person. Due to this, alcoholic addicts tend to consume more food which is later broken down to glucose. The excess food intake due to the influence of alcohol increases blood sugar levels – hence, disrupting homeostatic balance. In case of diabetic patients using insulin, consumption of alcohol may affect the medication leading to the medication not being effective making it harder to maintain homeostasis. Effective maintenance of the internal blood sugar requires the organs to be functioning at optimum20 (Brower et al: 559). Intake of any substance which destroys or alters the functionality of these organs affects the overall process of homeostasis. Alcohol consumption needs to be moderate to ensure that the blood sugar level is maintained by the endocrine system as well as maintenance of this liver at a healthy condition. Destruction of the liver through alcoholism, hence, affects the homeostatic functionality of the liver.
For homeostatic balance to be maintained there needs to be communication and coordination between the organs facilitating a series of mechanisms and processes in the human body. The coordination, in this case, is facilitated by the communication from the nervous system. The brain communicates on the state of imbalance within the organism’s system which requires a given organ to respond to the change to avert it towards the required state21 (Wang et al: 2010). The brain directs some glands to produce hormones inhabiting or facilitating a given process to ensure that the desired condition is achieved — insulin for instance is produced by beta cells in the endocrine pancreatic gland and is then secreted directly into the blood stream; where it stimulates hepatocytes from the liver to carry out carbohydrate metabolism When it has been adjusted to optimum levels, glycogen is produced to inhibit the function of the insulin hormone in order to prevent the blood glucose concentration getting too low. When body temperatures increase, for instance, the brain directs the excretory system to excrete more water to ensure that much heat is lost to the environment. When these temperatures fall below the sound levels, the brain directs activities involving more metabolism such as oxidation of the stored energy to provide heat energy required for maintaining the internal body temperatures22 (Tsai et al: 39). The brain transmits all sets of information to different organs on different activities required to maintain the internal environment balance enabling the organs
to respond promptly. The brain directs secretion of different hormones necessary in maintaining the body balance. For the brain to effectively function, it requires to be at its optimal operating condition. Alcohol consumption alters the communication between the brain and different organs thus affecting the process of homeostasis23 (Fitzpatrick et al: 146).
Alcohol consumption affects the status of the brain and therefore affecting the overall functionality of the brain. Excessive consumption of alcohol leads to the liver being unable to break down ammonia to urea for secretion. When this ammonia reaches the brain, it has far-reaching consequences leading to conditions such as memory loss or even seizures. The toxins in the blood make the addict have low memory conditions which even affects their interaction with people. These conditions affect the brain ability to coordinate other body organs into ensuring the internal balance is maintained at its optimal level24 (Barbagallo: 235). Seizure condition, for instance, occurs due to brain failure to communicate with other organs effectively making the body to go into a breakdown. The brain as noted earlier undertakes different functions such as coordinating with organs to ensure that the body temperature is maintained. Enzymatic activities in the body, for instance, require optimal temperatures to operate effectively if these temperatures are not controlled, they are denatured. Alcohol also affects the medulla part of the brain which is involved with the maintenance and control of body temperatures when this part has affected the coordination between the medulla and excreting organs such as the kidney becomes impossible. The kidneys or the skin, therefore, are not directed to excrete excess water leading heat loss. These high temperatures can cause a seizure to the body organs25 (Canto et al: 31)
Alcohol consumption increases the body temperature and when the brain cannot coordinate to have the temperatures controlled the body operations will fail. Alcohol consumption affects the nervous system causing peripheral neuritis; this affects the coordination between the brain and other parts of the body making it difficult for the body to maintain the required balance. Among the parts of the human brain affected by alcohol include brain tissues and brain cells. Alcohol consumption affects these brain receptors making them unable to receive and coordinate with other body organs26 (King: 2014). Another approach through which alcohol consumption affects homeostasis is through affecting the judgment aspect of the brain. Through this, the brain function is affected, and thus vital homeostatic activities are affected. Slowing down of the functionality of the brain also affects the rate at which these processes occur27 (Kim and Kim: 108). Due to alcoholism, therefore, the body may respond slower to given stimuli leading to other unnecessary complications or in some instance’s cases of insomnia and even seizure in some instances. Change in the brain neurobiology alters the brain function and thus affecting the future homeostasis process of the body.
Excessive alcohol consumption affects the process of homeostasis in various ways not only by changing the concentrations of many components of the blood but also affecting mechanisms of the vital organs involved in maintaining homeostatic balance. Due to this, alcoholism has far-reaching implications since it can completely alter the entire process of homeostasis. By
affecting the brain, for instance, alcohol proves to be more toxic and health damaging than many people perceive it, this is because the brain is the central point of all body functions. Alcohol consumption, therefore, is a threat to having a stable internal environment since it attacks the vital organs necessary for maintaining this balance. These organs include; the brain, the liver and the kidney as discussed above. Alcoholism health implications ought not to be ignored; this is because they are long lasting and take longer to be identified affecting some organs which are irreplaceable.
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