L23 Introduction to Renal Medicine

Question 1

Where are the kidneys positioned?

Answer 1

On either side of the kidney at the lowest level of the ribs (T11-L3). They are retroperitoneal organs.

Question 2

Give 7 functions of the kidney.

Answer 2

1. Homeostasis - maintain the electrolyte level by filtering out ions and secreting bicarbonate and the maintenance of osmolarity.
2. Fluid balance through the production of urine.
3. Production of erythropoietin. to stimulate the production fo new red blood cells.
4. Maintenance of blood pressure by the production of renin.
5. Acid-base balance through the production of bicarbonate and the excretion of protons.
6. Excretion of nitrogenous waste products such as urea. Also releases drugs such as antibiotics, digoxin, opiates and lithium.
7. Calcium and phosphate balance and the kidney activates vitamin D which is required for calcium absorption.

Question 3

Why can chronic kidney disease lead to renal osteodystrophy?

Answer 3

The kidneys do not produce activate vitamin D and so calcium is not retained. This leads to the parathyroid hormone becoming overactive. They start to release calcium from bones leading to bine disease. The parathyroid becomes so overactive it stops responding to drugs leading to tertiary hypoparathyoidsim. This can lead to fibrosis within the bone marrow and then you will not produce RBC and anaemia will not improve even with treatment with erythropoietin. This is renal-osteodystrophy.

Question 4

What is the normal range for sodium ions in the body?

Answer 4

133 - 146 mmol/L

Question 5

What is the normal range for potassium ions in the body?

Answer 5

3.5-5.3 mmol/L

Question 6

What is the normal range for urea in the body?

Answer 6

2.5-7.5 mmol/L

Question 7

What is the normal range for creatinine in the body?

Answer 7

64-104 μmo/L (male)

60-93 μmo/L (female)

Question 8

What is the normal range for bicarbonate ions in the body?

Answer 8

22-29 mmol/L

Question 9

What is the normal range for chloride ions in the body?

Answer 9

95-108 mmol/L

Question 10

Give examples of abnormal urine tests that can indicate issues with the kidney.

Answer 10

Haematuria (blood-not normal)
 Proteinuria - signs of kidney disease 
 Glucose (diabetes)
 Nitrites - signs of infection
Leucocytes - signs of infection 
pH