Colin Geddes Kidney Questions

Question 1

A 27yo female develops perfuse diarrhoea for 2 days and loses 4kg of body weight. Which of the body fluid compartments will change in size?
Intracellular, interstital or intravascular?

Answer 1

Interstitial and Intravascular - diarrhoea comes from the extracellular space.
‘Salty water is lost’ - hence salty water replacement for treatment.

Question 2

Along the length of the PCT, the concentration of sodium increases, decreases or stays the same?

Answer 2

Stays the same

As it is concentration, although sodium is being reabsorbed water is coming with it.

Question 3

A 20yo athlete starts taking protein shakes. The body metabolises protein to make muscle and in the process the liver produces urea. Which of the following is true?

1. The kidney will filter more urea.
2. The kidney will filter less urea.
3. There will be increased absorption of urea from the renal tubule.
4. They amount of urea in urine will increase.

Answer 3

The kidney will filter more urea.

Question 4

The most abundant cation in the extracellular fluid is?

Answer 4

Sodium

Question 5

Most abundant cation in the intracellular space is?

Answer 5

Potassium

Question 6

In a healthy adult with total extracellular fluid volume of 15L and intracellular fluid volume of 30L adding 1.5L of isotonic sodium chloride will increase the intracellular fluid volume by?

Answer 6

0L

The sodium chloride would stay in extracellular space

Question 7

What is the role of the macula densa?

Answer 7

Senses tubular flow

Thought to be via passing chloride

Question 8

Normal GFR in an average sized adult is

Answer 8

100ml/min

Question 9

A patient provides a urine sample and blood sample.
The urine volume is 2880ml.
The urine creatinine concentration is 5mmol/L.
The serum creatinine is 200micromoles/L.

What is the creatinine clearance in ml/min?

Answer 9

2.88 x 5 = number of mmol/L
Answer x 1000 to get micromol
Then divide by 200 
Then divide by 1440 
The x 1000 to get units. 

ANSWER = 50ml/min.