Introduction to nephrology Flashcards
What vessel supplies the kidney with blood?
Renal artery
What vessel drains the kidney with blood?
Renal vein
Where does the urine travel?
Down via the ureter to the bladder
What are the units that make up the kidney called?
Nephrons
How does the renal artery divide?
Renal artery -> capillary loop -> glomerulus
The capillary walls are specialised for transport of fluid and salt
TRUE or FALSE
True
Where does the fluid collect once it is filtered in the glomerulus?
In the Bowman’s Capsule
How many litres of blood are filtered a day?
180 L
How many litres of urine are produced a day?
2 L
Everyone starts with the same number of nephrons
TRUE or FALSE
FALSE
Not everyone starts with the same number of nephrons
Danish adults have less mean number of nephrons than Americans and Australians
What difference does nephron number make in the health of a kidney?
Nephron number accounts for differences in susceptibility to kidney disease
Premature babies = less nephrons and higher susceptibility to hypertension/ renal disease
What are the functions of the kidney?
Salt and water regulation
Maintains acid-base balance
Synthesises EPO
Activates vitamin D
Why is it important to regulate salt and water in the blood?
Maintains blood pressure
How do the kidneys maintain acid-base balance?
Absorbs and secretes electrolytes/ salts/ sugars
What is the role of EPO?
Stimulates RBC production
What does vitamin D regulate?
Calcium and phosphate concentration
What are methods by which we can measure kidney function?
Clearance of compounds
Filtration of water and electrolytes
Concentration of macromolecules in the urine
Production of vitamin D/ EPO
Whic compounds can we use to measure the clearance by the kidneys?
Urea and serum creatinine
What is creatinine?
Molecules formed by the breakdown of creatinine phosphate in the muscle
Produced at a constant rate by the body
Excreted unchanged by the kidneys
Why is measuring the filtration of water or electrolytes not practical to determine kidney function?
Have to collect urine over time to eradicate minute to minute alterations
Why is measuring the concentration of macromolecules in the urine a good way to determine kindey function?
A healthy filtration barrier should not let macromolecules pass through
What are examples of macromolecules?
Proteins
RBC
What are the 2 ways in which production of vitamin D or EPO can be measured in the blood?
Measure directly in blood
Can also measure indirectly - calcium phosphate balance or RBC count
Do men or women have higher GFR?
Men
Higher muscle mass - higher GFR needed
Do old or young people have higher GFR?
Young
Have higher muscle mass
What is the relationship between GFR and serum creatinine?
Non-linear relationship
Large change in GFR leads to a small change in serum creatinine
Large change in serum creatinine leads to a small change in GFR
How does renal function change with age?
GFR declines as we age - scarring of kidneys over time
Decline in GFR isn’t enough to lead to kidney disease
What is the average decline of GFR as we age?
0.4 ml/min/1.73m2
What are the symptoms of kindey failure?
Dirty blood - inadequate filtration
Fluid accumulation
High blood pressure
Anaemia
Bone disease
Lipid abnormalities
Why does fluid accumulate in kidney disease?
Acid-base balance is disrupted
Oncotic pressure is created
Causes water to build up in body tissues
Why does kidney disease lead to anaemia?
Imbalance in EPO synthesis
Why does kidney disease lead to bone disease?
Bones attempt to maintain serum calcium levels
Bone resorption = osteomalacia
Why does kidney disease lead to lipid abnormalities?
Disruption in the metabolism of lipids
What is the difference between acute and chronic kidney disease?
Acute - sudden loss of kidney function
Chronic - level of function is reduced but patients maintain health
Patients with CKD often maintain health
TRUE or FALSE
True
What are causes of kidney dysfunction?
Developmental/ genetic - may not grow normally, malformed
Acquired problems
What are examples of acquired problems that lead to kidney disease?
Blood supply problems
Blockage of urinary flow
Diseases (systemic or kidney-specific) that interfere with nephron function
What are the treatments of kidney disease?
If drug toxicity or infection - treat underlying cause
If immunological disease - immunosuppression
What can be done to slow down the progression of CKD?
Controlling blood pressure
This makes sure funcitoning nephrons last longer
What happens if you can’t treat the underlying cause of kidney disease?
Patient may develop end-stage kindey failure
What are the treatments for end-stage kindey failure?
Transplant
Maintenance hemodialysis - replaces kidney function
Why should we care about kidney disease?
Affects up to 3 million people in the UK
Increasing due to increases in disease - diabetes, aging population
Dysfunction is often unknown due to few symptoms
