Martin Cullinan is a 57 year old man who came to the emergency room,with 2 weeks of worsening leg swelling, fatigue and eye swelling. He hasdiabetes, which he has been poorly controlling over the last ten yearsor so.

1) What is a nephron? Draw and label the parts of anephron. Name the three processes of urine formation and indicate wherethey occur in the nephron.

2)Which substances are filtered across the glomerular membrane? Is glucose filtered? How and where is it reabsorbed?

3)In addition to glucose, which substances are reabsorbed and where in the nephron?

4)Which substances are secreted by which regions of the nephron?

5)This patient’s urinalysis showed > 1g/dL of glucose. Why do diabetic patients have glucosuria?

6)Classically,diabetics present with increased urination and, subsequently, increasedthirst. Why would increased glucose levels in the tubules causeincreased urination?

7) he kidney loses its ability toconcentrate the urine in part due to high glucose levels in the tubules.Generally, how does the kidney normally concentrate urine?

Lab tests obtained during this clinic visit show: pH 7.21; sodium ion or Na+ 131 mEq/L; bicarbonate ion or HCO₃– 12 mEq/L.

8)What can you say about Mr. Cullinan’s blood pH?

Mr. Cullinan is admitted for initiation of dialysis. His admission vitals are temperature 36.8⁰ C, heart rate 94/min, BP 160/50mmHg, respiratory rate 30/min.

9)Briefly describe the process of dialysis and why you think this patient was placed on it.

10)Whatcan you say about this patient’s respiratory rate? Why do you thinkthat is so? (Hint: consider the mechanism behind his compensation forhis acidosis.)