2.1 High Water and Salt 3

Table Of Content

Introduction 2

1.1 High Water 2

1.2 Physiological process 3

2.2 Physiological process 4

3.1 High Water and Exercise 4

3.2 Physiological process 5

4.1 Caffeine and Low Water 5

4.2 Physiological process 6

5.1 Experimental Design 6

5.2 Subject and Environmental control 7

5.3 Time Fame 7

Conclusion 7

References 8

Introduction

This report outlines the effects the four experiments conducted have on the production of urine within the body. The four experiments were; high water, high water and salt, high water and exercise, low water, and low water and caffeine. This report also outlines the physiological possess driving urine production in each of the experiments.

1.1 High Water

The high water section of the experiment was in part to establish a control group for comparison, so that any changes within the high water and salt, and high water and exercise groups had on urine production. However the high water group is also to show the effects of just water on the renal system.

The volume of urine produced by the subject, within this group, steadily increased with a slightly more rapid decrease after the peak. The first interval starts off at 110 mLs, the second rises by only 10mLs; the peak occurs at the third interval with 150mLs, the fourth interval decreases by 15mLs, the last interval shows the greatest drop in urine production within the high water experiment (Figure 1.1). The average temperature of the subjects also rose as the experiment progressed. The average temperature started off at 36.68ºc and steadily increased to 37.42 ºc (Figure 1.2). The average blood pressure how ever did not change. Specific gravity and pH also decreased.

1.2 Physiological process

When the body gains excessive water, out of proportion to sodium, the sodium serum concentration levels within the extracellular fluid becomes more dilute (REF PATHO TXT). With the imbalance of sodium and water content in the body there is a decrease in the extracellular fluid osmolarity (REF PATHO TXT). The lowered osmotic pressure is detected by the hypothalamic osmoreceptors inhibiting the release of antidiuretic hormone (ADH or vasopressin) (REF AMP TXT).

ADH works by binding to receptors in the collecting ducts increasing their permeability to water (ADH Vaso URL). Therefore without the release of ADH the renal collecting ducts’ permeability to water is low. The low permeability of the collecting ducts; stop the body from reabsorbing the water, and more water is lost to the body in urine and the more water that is lost in urine the more dilute the urine becomes.

With the increase in water within the urine, concentration of H+ ions decreases, rasing the pH of the subjects’ urine toward a more neural pH level. The specific gravity also decreases due to the lessened density of the urine (REF wikipedica).

2.1 High Water and Salt

The high water and salt experiment shows the effect salt has on the renal system. For this experiment the effects of salt with regards to the volume of urine produced over time is much less than the control group.

The graph for this experiment shows a steady rise, with a sharper decrease after the peek. The first interval starts off with 77mLs, with a rise of 10mLs for the second, the average volume then peeks at the third interval with 90mLs, then a slightly rapid decline to 58mLs at the fourth interval, at the final interval the average volume produced is a small 35mLs(Figure 2.1). There is also a slight increase in the average body temperature, the average temperature rose from 36.5ºC to 36.9ºC (Figure 2.2).

2.2 Physiological process

The increased intake of salt, out of proportion to water, causes the sodium serum levels to increase above the standard range of 145mEq/L (REF PATHO TXT). This increase in the sodium serum concentration causes an increase in the extracellular fluid osmolarity (REF PATHO TXT). The increase in the osmolarity of the extracellular fluid stimulates the hypothalamic osmoreceptors (AMP TXT). This stimulation causes the release of ADH from the posterior pituitary gland. With the presence of ADH the Collecting ducts’ become more permeable to water (Dr. Richard ADH Link). Water is then able to pass from the collecting ducts’ into aquaporins. Aquaporins carry the solute-free water from the kidneys back into the circulatory system, decreasing the extracellular osmolarity (ADH vaso URL).

3.1 High Water and Exercise

This section of the experiment was designed to show the effects exercise has on urine production. The volume of urine produced initially decreased, but increased and peeked at the third interval. The volumes of urine produced then steadily decreased from the third interval, to the fifth. The graphs show the initial average volume of 110mLs at the first interval, with a decrease of 18mLs for the second interval. The graph then peeks at the third interval with 133mLs, the fourth interval shows a decrease of 11mLs from the peek, the last interval shows the smallest volume within this experiment of 76mLs. the subjects average temperature however did not change

3.2 Physiological process

During physical exercise the body activates the sympathetic division of the autonomic nervous system, this causes an effect similar to the fight-or-flight response (AMP TXT). Blood vessels supplying the kidneys constrict, and blood is moved to the skeletal muscle (AMP + SIMON). The constriction of these blood vessels, suppling the kidneys, causes the glomerular filtration rate to decrease, producing less urine (Farquhar). The reduced blood supply to the kidneys also causes the release of renin (AMP). With the release of renin, the renin-angiotensin-Aldosterone cascade occurs. Aldosterone acts on the kidneys promoting the retention of sodium. With the retention of sodium the extracellular fluid osmolarity increases, stimulating the hypothalamic osmoreceptors to release ADH causing the kidneys to retain water (AMP). However, the body still needs to maintain fluid homeostasis and fluid is lost via other routes. Perspiration accounts for (8%), diffuse directly through the skin or exhaled accounts for (28%) (MARIEB), all these routes help to maintain body fluid balance.

4.1 Caffeine and Low Water

The low water group within this sub-experiment is the control group. The control group is setup to show the effects caffeine has on urine production. Within this experiment the effects of caffeine on urine production, is shown to have a diuretic effect (Figure 4.1). The results of this experiment shows, that caffeine has a profound effect on urine production, increasing the rate of urine produced substantially. Temperature for the control group decreased over the duration of the experiment, while the temperatures of the caffeine group initially rose slightly, then decreased (Figure 4.2). The blood pressures within both the control, and caffeine groups, did not change significantly.

4.2 Physiological process

Caffeine impacts greatly on the formation of urine. Caffeine acts as a mild diuretic, increasing the urine output (Kipp, A)(MED surg). Caffeine works by inhibiting the release of ADH from the posterior pituitary gland, thus decreasing the permeability of the collecting ducts to water (biocrawler).

However, caffeine also acts as a diuretic in another way. Because Caffeine is so chemically similar to adenosine, caffeine binds to the nurrotransmittor (Chawal). As caffeine binds to the nurotrasmittors it inhibits the effects of adenosine. Because adenosine causes vasoconstriction of the afferent glomerlus arteriols, caffeine blocks this effect increasing blood supply to the kidneys and increasing the glomerular filtration rate, consequently increasing urine output.(wikipedia).

5.1 Experimental Design

The experiments, and sub-experiment conducted, demonstrates the effects of High water, high water and salt, high water and exercise, low water, and low water and caffeine has on the renal system, within the set parameters of the experiments. However, the experiments conducted while valid, can be improved to produce more relevant data. Improvements such as, tighter control on subjects’, and their environment, before and during the experiment. Also an expanded duration for the experiments would greatly enhance the relevance of the data.

5.2 Subject and Environmental control

The control of the subject for the experiments conducted was not to a satisfactory standard. Although, a list of constraints was given to all participants, on activities, and food/beverage consumption, such as no caffeine consumption 2 hours prior to experiment. There is no way of being certain that these control parameters have been followed. So the results of the experiments could be unreliable, leading to contaminated data.

The environment in which the experiment took place was not a suitable one in which to achieve accurate data. The control group, especially, had to travel up and down flights of stairs to void. This factors in an amount of exercise that may have affected the results of the subjects not partaking in the high water and exercise group.

5.3 Time Fame

The experiment was conducted over 100minutes. This was time frame how ever was inadequate for this experiment. The sub-experiment Caffeine and low water is the prime example to show the inadequacy of the time duration. Caffeine takes 3-7 hours to be fully excreted from the body (MED surg), but the experiment only encompassed the first hour and 40 minutes of this process. The remainder of the caffeine in the body is still effecting the urine production, and would still provide results. Since the experiment only encompassed the first100minutes of the caffeine’s effect there is not enough holistic data to draw a solid conclusion (Research txt).

Conclusion

The experiments within this report have shown the effects they have on the production of urine in the body. It has also outlined the physiological processes of urine formation, while bring exposed to different elements and environments I.E. exercise. This report also shows that it is important as health professionals to consider the effects exercise, salt, and caffeine has on the hydration status as the experiments have shown, can influence normal fluid balance.

References

Biocrawler. (2005). Antidiuretic hormone. Retrieved 23rd September, 2006, from http://www.biocrawler.com/encyclopedia/ADH

Bowen, R. (1998). Antidiuretic Hormone (Vasopressin). Retrieved 15th September, 2006, from http://arbl.cvmbs.colostate.edu/hbooks/pathphys/endocrine/hypopit/adh.html

Brown, D., Edards, H. (2005). Lewis's Medical-Surgical Nursing Assessment and Management of Clinical Problems. Sydney: Elsevier

Copstead, L. C., Banasik,. J. L. (2005). Pathophysiology (3rd ed.). St. Louis: Elsevier Saunders.

Chawla, J. (2006). Neurologic Effects of Caffeine. Retrieved 1st October 2006, from http://www.emedicine.com/neuro/topic666.htm

Farquhar, W. B., Kenney, W. L. (1999). Age and renal prostaglandin inhibition during exercise and heat stress. Journal of Applied Phsiology, 86(6), 1-2.

Kipp, A. (2005). Science of Sport: Caffeine News - The Truth About Caffeine and Dehydration Retrieved 22nd September, 2006, from http://www.runnersweb.com/running/rw_news_frameset.html?http://www.runnersweb.com/running/news/rw_CTS_20050901_Caffeine.html

Klabunde, R. E. (2005). Cardiovascular Physiology Concepts. Retrieved 19th September 2006, from http://www.cvphysiology.com/Blood%20Pressure/BP016.htm

Marieb, E. (2002). Human Anatomy and Physiology 4th ed. Benjamin-Cummings Publishing Co. USA

Simon, H. B. (2006). Diet and Exercise: Exercise. Retrieved 25th September 2006, from http://www.medscape.com/viewarticle/535416?rss

Tortora, G. (2003). Principles of Anatomy & Physiology (10th ed.). Hoboken: John Wiley & Sons Inc.

Wikipedia. (2006). Relative density. Retrieved 21st September, 2006, from http://en.wikipedia.org/wiki/Specific_gravity

Student Name : Shadow Page 8 of 8 Date completed 8/10/06