Unit 4 (Homeostasis) Assignment Written Answers PDF

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Assignments - BIOL 1050 - Homeostasis Assignment Answers...

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Unit 4 (Homeostasis) Test - Written Answers Student Name: _Amelia Schaffer_____________________ ●

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Explain your diagnosis. Anthony describes feeling very sick the past week, and experiencing pain in his hands and feet. He additionally has not been keeping up with his diet and exercise regimen in order to subside his diabetes. Upon testing Anthony’s blood and x-raying his heart, it was discovered that his heart is a normal size and there were no abnormal findings in his chest, indicating that Anthony is not struggling from a heart related condition. However, upon testing his blood, it was discovered that the concentrations of urea and potassium in the blood are abnormally high. His concentrations of albumin were normal, and not abnormally low, ruling out the possibility of liver failure. The high concentrations present in Anthony’s blood is thus indicative of Kidney failure because Kidney failure causes increased concentrations of urea and potassium in the blood, and is especially prevalent for patients with high blood pressure and diabetes, a disease that Anthony evidently possesses.

What needs to change so that only the green solutes diffuse across the membrane? The pores of the semi-permeable membrane must increase to the size of a "medium pore" in order to allow small (green), but not large (red) solutes to be filtered.

What do you predict concentrations will be at 15 seconds? Explain your answer here. The solute has reached equilibrium at 60/60 at 10 seconds. The solute will continue to move in both directions in equal numbers. So, the concentration will be 60/60 at 15 seconds.

With countercurrent flow, diffusion happened in all regions of the filter. Explain why. When the dialysate and blood are flowing in the same direction, the blood and dialysate flow from the area of high concentration to the urea. The dialysis and concentration of urea in the bloodstream thus reaches an equilibrium, causing diffusion within the higher filter regions (II, III, IV, V) across the semipermeable membrane to stop. Contrastly, for concurrent flow, diffusion takes place in all regions of the filter because as the dialysis has no urea in it, a concentration gradient occurs across the membrane, meaning that the urea moves from the blood to the dialysis fluid through the process of diffusion across the membrane. The urea is thus removed from Anthony’s blood.

Using what you know about the sizes of urea and potassium, which graph shows what would happen to potassium during countercurrent flow? Explain your answer. The graph that diffuses in all regions of the filter shows what would happen to potassium during concurrent flow because the potassium levels in the dialysis are usually lower due to an incomplete equilibrium.

At the end of the countercurrent flow, Anthony's mass had decreased to reach the goal. What caused the decrease in Anthony's mass? The decrease in Anthony's mass was due to the excess water removed from Anthony's body during the dialysis session. Anthony's body was retaining excess water because patients with kidney failure retain around 5lbs of excess water due to the kidney's inability to remove excess solutes, water, and wastes, thus losing homeostasis.

Why did albumin not diffuse into the dialysate? Albumin did not diffuse into the dialysate because the pores were not big enough to allow the albumin through the membrane. The "medium size" pores were big enough to only allow the potassium and urea through the semipermeable membrane.

Case Summary Report (4 Questions) 1. Using Anthony's symptoms and initial lab results, describe how you diagnosed that the problem was kidney failure. 2. Describe the treatment goals for dialysis. 3. Explain how diffusion restored homeostasis during the dialysis treatment 4. Explain why countercurrent flow met the goals and why parallel flow did not meet the goals.

1. Anthony describes feeling very sick the past week, and experiencing pain in his hands and feet. I hypothesized that this pain could be due to the excess water in Anthony’s body caused by kidney failure. He additionally has not been keeping up with his diet and exercise regimen in order to subside his diabetes. Upon testing Anthony’s blood and x-raying his heart, it was discovered that his heart is a normal size and there were no abnormal findings in his chest, indicating that Anthony is not struggling from a heart related condition. However, upon testing his blood, it was discovered that the concentrations of urea and potassium in the blood are abnormally high. His concentrations of albumin were normal, and not abnormally low, ruling out the possibility of liver failure. The high concentrations present in Anthony’s blood is thus indicative of Kidney failure because Kidney failure causes increased concentrations of urea and potassium in the blood, and is especially prevalent for patients with high blood pressure and diabetes, a disease that Anthony evidently possesses. 2. The treatment goals for dialysis include restoring Anthony’s homeostasis by keeping his albumin at a normal level (2.5-3.5 g/dL), reducing his urea and potassium back to normal levels (urea: 10-26 mg/dL, potassium: 3-5.5 mmol/L), and decreasing Anthony’s body mass to 81-82 kg by removing excess water. 3. Diffusion restored homeostasis during the dialysis treatment because diffusion took place in all regions of the filter. This is because, as the dialysis has no urea in it, a concentration gradient occurs across the membrane, meaning that the urea moves from the blood to the dialysis fluid through the process of diffusion across the membrane. The urea is thus filtered out of Anthony’s blood, and homeostasis is restored to his body. 4. Parallel flow did not meet the goals of the dialysis treatment because it did not effectively bring Anthony’s urea and potassium levels back to normal. This is because in parallel flow, the dialysate and blood are flowing in the same direction, and the blood and dialysate flow from the area of high concentration to the urea. The dialysis and concentration of urea in the bloodstream thus reaches an equilibrium, causing diffusion within the higher filter regions (II, III, IV, V) across the semipermeable membrane to stop. Essentially, with parallel flow, diffusion of urea happened at regions I and II but not III, IV, or V because there was no concentration gradient for urea in regions III, IV, or V. The concurrent flow met the goals of dialysis and effectively brought Anthony’s urea and potassium levels back to normal because diffusion took place in all regions of the filter, thus filtering the urea from Anthony's blood and returning his body back to a state of homeostasis....