The Production of Urine in the Human Body - Case Study Example

Renal Structure Index Introduction 2 A: High Water 3 B: High Water + Salt 5 C. High water + Exercise 6 D. Low Water (250ml) + Caffeine 8 E: Remarks 11 F: Conclusion 11 Figure 1: A Bar Graph Showing the Rate of Urine Production over Time 4 Figure 2: A bar graph showing a rate of urine production against time for high water + salt 6 Figure 3: A bar graph showing rate of urine production against time in subjects with high water and exercise 8 Figure 4: A bar graph showing rate of urine production against time of low water 10 Figure 5: A bar graph showing rate of urine production against time of low water + caffeine 11 Introduction Urine is a liquid by product secreted by the kidneys in the human body. The process by which urine is produced is referred to as urination. Through the process of urination the body gets rid of toxic soluble substances through the urinary system consisting of the kidneys (nephrons), ureters, bladder and the urethra. Soluble wastes are extracted by the kidneys from the bloodstream. Excess water, sugars and other compounds are reabsorbed back to the body while high concentrations of urea and other toxins make up the urine. Kelly (1988, pg.34) gave a detailed description of the of urine composition: organic and inorganic constituents, physical and chemical properties and its behavior in various circumstances. Urine is made up of more than 25% water, urea 9039/l, potassium 0.750g/l, chloride 1.87g/l, sodium 1.17g/l and other dissolved ions and compounds (Putman, 1997, pg 5). The color usually ranges from amber to pale yellow depended on the presence or absence of urobilin. The odour will always be dependent on the food taken while normally ranges from 4.3 to 8. The rate and the volume of urine produced is dependent on various factors including hydration, taking a lot of water, activities like exercises, environmental factors, health, salt intake and intake some substances like caffeine. The average rate of urine production of in a healthy adult human being should be 1-2L/day. Production of a lot of urine is called Polyuria while production of too little urine is called oliguria. Both conditions need medical attention when they occur. This study investigates the effects of four situations on the production of urine in the human body. The four situations include high water, high water and exercise, high water and high salt, low water and low water and high caffeine. The physiological process motivating the urine production is also outlined in this study. A: High Water This high water experiment was set up to establish a control experiment for comparison to effects of high water + exercise, and high water + salt on rate of urine production. The set up also assisted in to show the effects of taking a lot of water on rate of urine production. The rate of urine production of in the subjects sampled in this research was measured by the volume of the urine after taking a lot of water after 20 minutes and computed to get the rate in ml per minute The mean rate was 3 ml/min with a standard deviation of 1.419 (Barclay et al, 1947, pg 327-337). There was a great variation in the average urine produced during diuresis ranging from 7.15 ml to 160 ml giving variations in the rates as shown in figure 1 below. Figure 1: A Bar Graph Showing the Rate of Urine Production over Time When there is high water intake in the body, this throws the sodium ions out of proportion leading to decreased levels of concentration of the sodium serum in the extracellular fluid (Yoshimura, et al, 2003). ). This imbalance then leads to low extracellular fluid osmolarity and causes low osmotic pressure which is detected by the osmoreceptors in the hypothalamus. This inhibits the production of the antidiuretic hormone (Ridson, Sloper, and de Wardener, 1968). The decreased release of the antidiuretic hormone (ADH) water permeability in the collecting ducts is lowered hence water is not reabsorbed back to the body. Therefore, water is lost by the body in the urine and the urine is very dilute. The more the water in the urine, the more the there is a decrease in the concentration of H+ ions changing the pH to be close to a more neutral level. There was a slight decrease in specific gravity due reduction in the urine density (Bowen, 2008, pg 3). B: High Water + Salt The rate of urine produced by subjects who had taken high water and high salt was high for the first 1 hour and reached its peak at 80 minutes. The rate then started slowing down and drastically came down as the volume produced came to 50 ml after 100 minutes. The mean rate of production was lower than the one experienced in the first case as the volume of urine produced in the High Water sample was high, getting to as high as 160 ml. the highest amount of urine produced in this case was lower (James, 1992) as can be clearly seen in the graph below. A paired sample t-test done to investigate the difference in physiological composition of this sample (m=60ml, sd =30.675) revealed that there was no significant difference between the composition of the urine produced in the high water sample and the high water + salt sample (t=45.145, df =27, p=0.785, α=0.5). The BP and temperature remained the same throughout the experiment. This experiment shows the effect of salt on the renal system. In this experiment, the effect of salt on the volume of urine produced is much less than that observed in high water alone. The graph below shows a steady rise in the volume produced with a sharp decrease after the peak is reached. The first interval kicks off with 2.75ml/min with a rise of 2ml/s2. There was also a slight increase in body temperature; from 36.5oc to 36.8oc Figure 2: A bar graph showing a rate of urine production against time for high water + salt Increased salt intake causes the Sodium serum levels to rise above the normal range of 145 mEq/L (Copstead and Banasik, 2003, pg 23-5). This rise in the levels of sodium serum increases the exracellular osmolarity (Marieb, 2001, pg 32). This then leads to an increase in the release of ADH causing the ducts to be more permeable to water. Water then passes into the aquaporins form the collecting ducts. The water in the aquaporins is then carried back to the circulatory system leading to a decrease in the extracellular osmolarity. C. High water + Exercise In this sample, the subjects took a lot of water accompanied by exercise. The Graph shown below reveals that the rate of urine production was similar to that of subjects with high water only. The trend is similar to the one observed for the line graph representing the rate of urine production for high water only. It rises steadily for the first 40 minutes reaching a high of approximately, 150 ml, slightly lower than that of the high water alone sample, 160ml. The temperature and the blood pressure changes slightly after 100 minutes which can be attributed to the heart beating fast during the exercise to offset the accumulating lactic acid in the muscles (James, 1992). In the process, the kidneys help in carrying out the excretion of the lactic acid by producing a lot of urine (Abharzck, 2000). The volume of urine produced in this sample seems to be slightly lower than that of the first sample because more water seems to be lost though sweating in this sample. It is however higher than that produced for the high water + high salt because the nephrone tubes reabsorbed more water leaving the urine to be slightly concentrated to get rid of the excess salt from the body. Research done by Bar (2003, pg 56-63) demonstrated that there are great variations in the composition of urine resulting from episodes of strenuous exercise. The body sympathetic division is usually activated during vigorous physical exercises causing a fight-or-flight response. There is a constriction in the blood vessels supplying the kidneys causing reduction in the glomerular filtration rate, resulting in low urine production. The decrease in blood supply to the kidneys causes the production of rennin resulting in the formation of the rennin-angiotensin-Aldosterone cascade. As a result, sodium is retained by the kidneys which stimulate the hypothalamic receptors to produce ADH resulting in retention of water by the kidneys. However, there is still need to maintain the fluid balance during the physical exercises which is attained by perspiration (8%) and diffusion directly through the skin (28%) (Marieb, E. (2001). Figure 3: A bar graph showing rate of urine production against time in subjects with high water and exercise D. Low Water (250ml) + Caffeine The rate of urine production in the subjects with high caffeine intake and low water was different as can be seen in the above graph. An independent sample t-test was employed to find out the difference in the mean rate of urine production in subjects with low water (m= 51.5ml, sd = 56.7) and that of subjects with low water and high caffeine (m=62.21, sd =66.1). The results (t=-1.485, df =288, p=0.139, α=0.5) revealed that there was a significant difference between the rate of urine productions in the two types of subjects (Brookes and Brookes, 2007). The possible explanation for such kind of discrepancies in the results is that caffeine is considered to be diuretic. It is believed that taking caffeinated drinks causes people to lose fluids (Greenberg, 2005). This is clearly shown in the graph above as the subjects with caffeine + low water released large volume of water reaching a high of 80ml after 60 minutes as compared to the ones with just low water. The highest was 65 ml. A research by (Goldstein, 1997) shows that caffeine intake affects fluid balance. It causes urine output to increase leading to loss of fluids causing imbalance in the body. This could clearly be seen in the subjects’ urine which a lot of caffeine in the urine volume as compared to that of low water which had very little or no traces of caffeine in the urine volume . Compared to the low water set-up, this experiment shows the effect caffeine has on urine production. Caffeine seems to have diuretic effect as shown in the graph below. The graph shows that caffeine has a significant effect on urine production leading to an increased on the rate of urine produced significantly. The temperature decreased over the duration rose for the duration of the experiment as compared to lat of low water which decreased over the experiment period. The blood pressure for the low water and the low water + caffeine did change. Caffeine has a great impact on urine formation due to it diuretic properties leading to an increase in the amount of urine produced. It inhibits the release of ADH by the pituitary gland leading to low water permeability in the collecting ducts (Biocrawler. (2009). Chemical, caffeine is similar to adenosine and bids to the neurotransmitter (Chawla, J. (2007) and inhibits the effects of adenosine (vasoconstriction of the glomerular arterioles) and leads to increases blood supply t the kidneys, increases the glomerular filtration rate and finally increase in urine production. Figure 4: A bar graph showing rate of urine production against time of low water Figure 5: A bar graph showing rate of urine production against time of low water + caffeine E: Remarks The experiment gave a good insight on the pathophysiology of the renal function of the subjects in different circumstances. However, there were some limitations that came about when carrying out this research. For example the study was carried out over a period of approximately 100 minutes (Brown, D. and H. Edwards (2008). There it did not investigate the effects of high water, high salt, exercise and caffeine on regular basis. This is because a one time intake of high volumes of these substances might affects the body differently from when they are consumed on a daily basis. Therefore, a long duration for the study would greatly improve the relevance of the data collected. Use of tighter controls on the environment and the subjects, before, during and after the experiments could give better results. F: Conclusion This study has shown the effects the different substances have on urine production. The phathophysiological processes have also been outlined to show haw urine is formed in the different experiments. This report is important to health professionals who have to consider salt, caffeine and exercise and their effects on the hydration and how they can throw the normal fluid balance out of proportion (Tortora,, 2005, pg 4-5). References Abharzck AC. J Am Coll Nutr, Oct 2000;vol 19(5):pp 591-600. Biocrawler. (2009). Antidiuretic hormone. Longhorn pulishers, UK Bowen, R. (2008). Antidiuretic Hormone (Vasopressin).   Retrieved 15th September, 2006, Brookes, JA and Brookes. Am J Clin Nutr, June 2007;vol 85:pp 392-398. Brown, D. and H. Edwards (2008). Lewis's Medical-Surgical Nursing Assessment and Management of Urinal Problems. Sydney: Elsevier Chawla, J. (2007). Neurologic Effects of Caffeine, New York ;NY, GruMcHull Publishers, pg 1-78 Copstead, L. C., Banasik,. J. L. (2003). Pathophysiology (3rd ed.). St. Louis: Elsevier Saunders. Goldstein A. Exp Clin Psychopharmacol. Nov 1997;vol 5(4):pp 388-392. Greenberg J. Int J Obes (Lond), Sep 2005;vol 29(9):pp 1121-1129. International Food Information Council Foundation Iso H. Ann Intern Med, April 2006;vol 144(8):pp 555-562. James JR. Am J Psychiatry, Jan 1992;vol 149(1):pp 33-40. Kelly, John F. "The Urine Cure and Other Curious Medical Treatments" Hippocrates Magazine. (May/June 1988) Marieb, E. (2001). Human Anatomy and Physiology 4th ed. Benjamin-Cummings Publishing Co. USA Ridson, R.A., de Wardener. J.C, and, Sloper, H. E. (1968) Relationship between renal function and physiological Changes in renal functions. Lancet 2: 363–366, Tortora, G. (2005). Principles of human Anatomy & Physiology (10th ed.). Hoboken: John Wiley & Sons Inc. Yoshimura de Bal, Y, et al, (2003) Osmolarity in renal function of people with high body water levels. Am J Physiology Read More