Renal Therapeutics 1: PM1A kidney notes

Question 1

What is the function of the renal system?

Answer 1

1. Homestatic regulation of water and inorganic ion balance
2. Removal of metabolic waste products and foreign chemicals from the blood and their excretion in urine

This include:

• Erthyropriatin
• Renin
• Vitamin D3
• Prostaglandins

Question 2

What are the three processes of the elaboration of the urine?

Answer 2

1. Filteration occurs in the glomerulus
   - Filtration of blood plasma forms filtrate this enters the tubules (now called tubular fluid)
2. Reabsorption
   - Movement from tubular fluid to blood (transcellular or paracellular)
3. Secretion
   - Movement from blood to tubular fluid

Question 3

What molecules form the filtrate and what cannot form it?

Answer 3

Water, Urea and glucose can

Inulin, myoglobin, haemoglobin, Albumin (proteins) cannot

Question 4

What is diabetes insipdus caused by?

Answer 4

1. The inability of the kidneys to conserve water (frequent urination and extreme thirst)
2. This is due to a lack of ADH due to damage to hypothalamus or result of surgery or pituitary gland

Question 5

If you have micturition abnormalities, what does normally arise from?

Answer 5

Lower urinary tract problems such as infection, inflammation

Question 6

What do fluid and electrolyte imbalances commonly result from?

Answer 6

Renal impairment caused from haemodynamic consequences with cardiovascular features (BP, oedema, shortness of breath)

Question 7

What do osmotic imbalances commonly result from?

Answer 7

Neurological features

Question 8

What do uraemia commonly result from?

Answer 8

1. Symptoms of renal failure (high level of blood urea)

2. Azotaemia (high level of nitrogenous products)- lethargy, nausea, vomiting, anorexia

Question 9

What does the rate of filtration measure?

Answer 9

Efficacy of the kidney but difficult to measure

Question 10

What does clearance measure?

Answer 10

Hypothetical volume of blood from which a substance would be completely removed by filtration in 1 minute

Question 11

What does it mean when plasma clearance is less than GFR?

Answer 11

When substance is filtered and reabsorbed but it isn’t secreted (urea and glucose)

Question 12

What does it mean when plasma clearance is more than GFR?

Answer 12

The substance is filtered and secreted, but not reabsorbed (PAH and paraaminohippuric acid)

Question 13

What substance is freely filtered from the blood capillaries into the bowmans capsule, neither reabsorbed or secreted by the tubules and has no overt effect on renal metabolism?

Answer 13

Plant polysaccharide inulin and creatinine (produced at a fairly constant rate in the muscle)

Question 14

What is used to measure the GFR normally and why?

Answer 14

Creatinine- just filtered, no reabsorption, little bit of secretion

Question 15

How can you display an image of a kidney clearly?

Answer 15

Intravenous excretory urogram (IVU)

Produces a series of images which show any inequality of perfusion of kidneys, rate of renal and bladder filling.