Osmosis: Discussion and Clinical Implication

All living things and the process of diffusion and osmosis

All living things are physiologically designed to obtained various materials from the environment, for instance, the cells of all living things are conditioned to receive oxygen, nutrients as well as water from their surrounding. At the same time, these animals, as well as plants, have to get rid of the excess waste produced during biological processes such as respiration and digestion. However, the movement of these selected materials has to pass in and out of the cells through the cell membrane which is selectively permeable. The successful movement of things in and out of the cells depend on the existence of a concentration gradient. Therefore the process by which molecules of a specific substance move from areas of high concentration to where there is low concentration is known as diffusion (Hasni, Patrick and Dumais, 1508).

Osmosis and the three types of osmotic solutions

Osmosis, on the other hand, involves the transfer of solvent molecules from a region considered to have a high concentration of water to another region where the concentration of the same is low. Osmosis is sometimes referred to like a particular type of diffusion since it also involves the movement of molecules from regions of high density to low density.

There are three known types of osmotic solutions, and they include hypertonic, hypotonic and isotonic solutions (Krogh, 8). The three solutions distinguish osmosis from diffusion, and one of the most common difference is the fact that in diffusion the molecules move down a concentration gradient while in osmosis the molecules move down as well as across the memberane. Both, however, are types of passive transportation. Hypertonic solution occurs when the solute concentration is higher outside the cell than inside it while hypotonic solution the solvent concentration is higher than that of the cell cytoplasm. The isotonic solution, however, is when the solvent and concentration is equal both outside and inside the cell (Padua, 1163).

Hypotheses related to red blood cells and osmotic solutions

The primary objective thus determines the three solutions in a living cell membrane. From the objective, hypotheses are formulated as follows:

H1: if red blood cells are placed in a 0.85% sodium chloride solution, the cells will not shrink because no water will be leaving the cells.

H2: if the red blood cells rea placed in a 10% sodium chloride solution, the cells will shrink, because water will move out of the cells.

H3: if the cells are placed in distilled water, the cells will enlarge and burst because water will move into the cells making then larger in size.

Material and Methods

The materials used in this experiment are sodium chloride, distilled water, compound microscope, three microscope slides, a medicine dropper, test tubes, and three glass cover slides. All these materials are used to investigate osmosis through the membrane of the Red Blood Cell. For this experiment, a small amount of the Red Blood Cell was dropped into the microscope slide then covered by a glass cover slide. The cover slide was used to control and determine the experimental groups used to experiment. The three microscope slides were labeled alphabetically from A through to C. A was used to represent an Isotonic solution while B served as hypertonic and C hypotonic solution consequently. The blood sample was then dropped into the slide A with a sodium concentration of 0.85 %, B with a concentration of 10 % and for slide C the Red Blood Cell was mixed with the distilled water and covered with the glass cover. The final step involved observing the three experimental samples under a light compound microscope with 600X magnifications and the results recorded accordingly. The materials used for the experiment were then washed with soap and water and placed on the bench next to the sink.

Results

From the observation made on the compound microscope, the size of the blood cells remained the same on the isotonic solution that is for slide A; In the case of the slide B, it was seen that the blood cells had reduced in size from their original size, the cells are described as having shriveled. For the case of slide C, the cells increased in size while others had burst. The diagram below illustrates the observation made during the experiment and which will be discussed in the subsequent paragraph.

Discussion and Clinical Implication

The size of the red blood cells that were placed on plain glass slides did not change in shape or size. These were used as the control group in this experiment. They were used to determine any changes that would have occurred during the process.

The size of the red blood cells in the 0.85% sodium chloride solution remained the same, and this is because the concentration of sodium chloride is equal on the inside and outside of the cell, meaning this was an isotonic solution. The passive transportation of molecules via osmosis becomes impossible since there is no concentration gradient between the solution and the cell. The cell membrane, therefore, allows equal movement of solvent molecules or water both inside and outside the cell. From these results, the hypothesis that states the cells will not shrink is confiemed as true.

The cells, however, shrivels when subjected to the 10% sodium chloride solution. This is because the concentration of solute molecules outside the cell is higher than that inside the cells. For this scenario therefore, there exists a concentration gradient that forces the cell membranes to permit movement of solvent or water molecules from the area of high concentration- inside the cells to a lower concentration which is outside the cell. The hypothesis is thus confirmed and this is a hypertonic solution.

In the distilled water solution, it was observed that the cells were swollen and some had burst. The concentration of solute molecules in distilled water outside the cell membrane was lower than on the inside of the cell and this caused cell membrane to allow the movement of more solvent molecules inside the cells. The distilled water acted as hypotonic solution and thus it made the red blood cells to swell and burst.

In the distilled water, no cells were observed even after prolonging the stay on the microscope slide. The cells were washed away by the excess water that was used during the experimentation.

Sources of errors

However, the experiment was not without errors. One of this arose from the fact that the slides did not dry well, and this greatly affected the results especially with the cells in solution C.

Another error was that excess distilled water was used during the experiment. This may have caused the red blood cells to be washed away and thus nothing was observed through the microscope.

Clinical implications and conclusion

Clinically, osmosis is applied in the treatment of patients. Medicines are made to be isotonic to body fluids. This is to make them act well without draining body cells their fluids. This is also to avoid irritation at the sites of administration of the drugs. For instance, drugs meant to be applied in the eyes, such as eyedrops are made isotonic to prevent tearing after application (Norris, 67).

In conclusion, the hypotheses were confirmed. Solution A 0.85% was isotonic to the red blood cells, and therefore there was a balanced movement of water molecules in and out of the cell. Solution B was hypertonic and hence water was drawn from the cells while solution C was hypertonic, more water was drawn into the cells and they were swollen and burst.

Work Cited

Hasni, Abdelkrim, Patrick Roy, and Nancy Dumais. "The Teaching and Learning of Diffusion and Osmosis: What Can We Learn from Analysis of Classroom Practices? A Case Study." Eurasia Journal of Mathematics, Science & Technology Education 12.6 (2016).

Krogh, August. Osmotic regulation in aquatic animals. Cambridge University Press, (2015).

Norris, Elvin. “The pH and Tonicity of ophthalmic solutions.” Jama opthalmology journal, (2013).

Padua, April P., et al. "Isotonic versus hypotonic saline solution for maintenance intravenous fluid therapy in children: a systematic review." Pediatric nephrology 30.7 (2015): 1163-1172.