You are a physiologist on a space flight to a distant planet. You discover aliens inhabiting the planet and they are willing to submit to your tests. You discover that the aliens kidney handles the sugar alcohol mannitol just like our kidneys handle inulin(not the same as insulin). You also test the alien for its renal handling of glucose. The data is: Plasma level(constant over 24 hrs):6g/dL of mannitol and 2g/dL of glucose. 24 hr urine sample: volume of 2L, containing 144g mannitol and 52g glucose. What is the aliens GFR? What is the aliens clearance rate for glucose? How does the alien kidney handle glucose? I have struggled with this for hours now, any help will be appreciated!

Question

You are a physiologist on a space flight to a distant planet. You discover aliens inhabiting the planet and they are willing to submit to your tests. You discover that the aliens kidney handles the sugar alcohol mannitol just like our kidneys handle inulin(not the same as insulin). You also test the alien for its renal handling of glucose. The data is: Plasma level(constant over 24 hrs):6g/dL of mannitol and 2g/dL of glucose. 24 hr urine sample: volume of 2L, containing 144g mannitol and 52g glucose. What is the aliens GFR? What is the aliens clearance rate for glucose? How does the alien kidney handle glucose? I have struggled with this for hours now, any help will be appreciated!

Answer 1

this is an exact question on my physiology final. i'd like to know the answer too

Answer 2

To find the alien's glomerular filtration rate (GFR), we can use the formula:

GFR = (Urine concentration x Urine volume) / Plasma concentration

First, let's calculate the GFR for mannitol:

Plasma concentration of mannitol = 6g/dL
Urine concentration of mannitol = 144g / 2L = 72g/L
Urine volume = 2L

GFR_mannitol = (72g/L x 2L) / 6g/dL

To simplify the units, let's convert L to dL:
GFR_mannitol = (72g/L x 20dL) / 6g/dL
GFR_mannitol = 240dL/min

Therefore, the alien's GFR for mannitol is 240 dL/min.

Now, let's calculate the clearance rate for glucose:

Plasma concentration of glucose = 2g/dL
Urine concentration of glucose = 52g / 2L = 26g/L

To find the clearance rate, we can use the formula:

Clearance rate = (Urine concentration x Urine volume) / Plasma concentration

Clearance_rate_glucose = (26g/L x 2L) / 2g/dL
Clearance_rate_glucose = 26dL/min

Therefore, the alien's clearance rate for glucose is 26 dL/min.

In terms of how the alien kidney handles glucose, the clearance rate for glucose indicates that the alien kidney is able to filter glucose freely through the glomerulus into the urine. This suggests that the alien lacks the ability to reabsorb glucose from the renal tubules back into the bloodstream, leading to the excretion of glucose in the urine. This condition is similar to a medical condition called glucosuria, where excessive amounts of glucose are excreted in the urine due to the inability of the kidneys to reabsorb all the filtered glucose.