Renal and Bladder Pathophysiology

Question 1

What is homeostasis?

Answer 1

The tendency for an organism (cell) to regulate its internal conditions, usually by a system of feedback controls, so as to stabilise health and functioning regardless of outside conditions.

Question 2

What are the classical symptoms of sodium overload?

Answer 2

High BP

Raised JVP

Oedema

Question 3

How should sodium overload as a result of chronic renal failure be treated?

Answer 3

Reduce intake

Treat with haemodialysis (3 x 5hrs weekly)

Question 4

What proportion of cardiac output flow to the kidneys?

Answer 4

~ 25% (1.5 L/min)

Question 5

What is the formula for creatinine clearance?

Answer 5

Creatinine clearance = UV / P

where:

• U = urine concentration of creatinine
• V = volume of urine
• P = plasma concentration of creatine

Question 6

What are the variables used to calculate eGFR?

Answer 6

Serum creatinine

Age

Sex

Ethnicity

Question 7

When is eGFR unlikely to be of value?

Answer 7

When blood flow is low

• tends to be overestimated

Question 8

What are the mechanisms control fluid and electrolyte balance?

Answer 8

ADH

Aldosterone

Macula densa

Renin

Question 9

What are the dangers of hyperkalaemia?

Answer 9

Potentially dangerous heart arrythmias

Question 10

What is the short term treatment for hyperkalaemia?

Answer 10

Salbutamol

Insulin

Question 11

What is the long term treatment for hyperkalaemia?

Answer 11

Haemodialysis

Haemofiltration

Question 12

What are the dangers of hypernatraemia / Na+ retention?

Answer 12

Dehydration leading to life threatening illness

Question 13

How should hypernatraemia be managed?

Answer 13

Normally down to dehydration =>

Correct water/fluid

Question 14

What are the dangers of metabolic acidosis?

Answer 14

Cardiac arrythmias

If unmanaged => inability to form bicarbonate resulting in death

Question 15

What type of disturbances may result from renal failure?

Answer 15

Hyperkalaemia

Hypernatraemia

Metabolic acidosis

Question 16

How should metabolic acidosis be managed?

Answer 16

Dialysis

Bicarbonate infusion

Question 17

Which other conditions can metabolic acidosis result from?

Answer 17

Lactic acidosis

Ketoacidosis

Intoxication

Question 18

What is metabolic acidosis?

Answer 18

A condition when the body produces too much acid, or the kidneys are not removing enough acid from the body

Question 19

What are the causes for Na+/H2O overload leading to hypertension?

Answer 19

Glomerular disease

Decreased GFR

Establised renal failure

Question 20

How should hypertension caused by Na+/H2O overload be treated?

Answer 20

Restriction of Na+/H2O

Diuretics

Dialysis

Question 21

What are the signs and symptoms of renin-mediated hypertension?

Answer 21

Hypertension

High renin

Not overloaded

Question 22

What is the cause of renin-mediated hypertension?

Answer 22

Interstitial disease

Ischaemic renal disase

Question 23

How should renin-mediated hypertension be treated?

Answer 23

ACE inhibitors

Other antihypertensives

Question 24

How should anaemia in renal disease be treated?

Answer 24

Administration of:

• Erythropoetin
• Parenteral iron

Question 25

Describe the EPO cycle

Answer 25

Low O2 tension at proximal tubule --> EPO produced --> Stimulates stem cells in bone marrow --> Stem cells become RBC --> increased O2 Negative feedback on EPO

Question 26

Which hormones does the kidney produce?

Answer 26

EPO Renin Calcitriol (active form of Vit D)

Question 27

Which enzyme in the kidney makes the active form of vitamin D i.e. calcitriol?

Answer 27

1-alpha hydroxylase

Question 28

Describe calcium-phosphate metabolism in renal disease

Answer 28

Reduced phosphate clearance Reduced vitamin D metabolism => hyperparathyroidism => changed in bone turnover => metastatic calcification

Question 29

Name the parts that form the urinary bladder

Answer 29

Detrusor Bladder body Bladder base Uretero-vesical junction Trigone Urethra Note outer layers: Smooth muscle, lamina propria, urothelium

Question 30

What is the motor nerve supply to the bladder?

Answer 30

Sympathetic: arise from hypogastric plexuses and nerves Parasympathetic: from the pelvic splanchnic nerves and the inferior hypogastric plexus

Question 31

What is the sensory nerve supply from the bladder?

Answer 31

General visceral afferent fibres - Superior surface: follow symp. efferent nerves - Inferior surface: follow the parasymp. efferent nerves

Question 32

How does impaired bladder function affect renal function?

Answer 32

Reflux nephropathy => obstruction