Lecture 31: Urine Composition, functions of the kidney, and basic nephron processes Flashcards
How much normal urine do we produce in a day?
1.5L/day
What percentage of urine is water?
95% - 98%
What are three metabolic wastes that our body excretes through our urine?
creatinine
urea
uric acid
What is present in the urine that can determine the pH?
H+, NH3
What ions are present in the urine?
Na+, K+
Does normal urine contain drugs and toxins?
yes
What 10 things are present in normal urine?
water creatinine urea uric acid H+ NH3 K+ Na+ drugs toxins
What things do you expect in pathologic urine (6)
glucose protein blood haemoglobin leucocytes bacteria
What does normal urine look, taste and smell like?
- looks clear, light or dark amber look
- tastes acidic (not sweet)
- smells unremarkable
What does pH depend on and what is the approximate pH for a vegetarian and meat eater?
diet
vegetarians: pH up to 7.2
meat eaters: pH 4.8
What does pathological urine look, taste and smell like?
- looks golden, red, brown, blue
- taste sweet
- smells like fruit or rotten
What 5 things can we look for in a urinalysis?
red blood cells spez. gravity glucose protein pH
What is spez. gravity?
it gives an indication where the osmotic value of association is
Is blood present in plasma and urine?
no, neither
What is the range of spez. gravity in the plasma and urine?
285 - 300 mOsmol/L in plasma
50 - 1335 mOsmol/L in urine
Is glucose present in the plasma and the urine?
yes in the plasma but not in the urine
What is the pH range in the plasma and the urine?
plasma: 7.4
urine: 4.5 - 8.0
What are 9 functions of the kidney?
- ________ production
- M________
- G________
- _______ regulation
- excretion of ______, endogenous _______ and _________
- reabsorption of ________
- _____/______ homeostasis
- ________ homeostasis
- hormone production
- metabolism
- gluconeogenesis
- pH regulation
- excretion of drugs, endogenous metabolites and toxins
- re-absorption of nutrients
- salt/ion homeostasis
- water homeostasis
What two things determine blood pressure and why?
Na+ and H2O because these two determine the blood volume
Why is it important that the kidneys produce hormones, using EPO as an example?
What does chronic renal failure mean in terms of the number of red blood cells and haemoglobin in the blood?
- low O2 levels are detected by the kidneys
- the kidney releases EPO which stimulates the bone marrow to produce more red blood cells
- chronic renal failure means that there are low levels of red blood cells/ haemoglobin in the blood
What is meant by the metabolism function of the kidneys?
the kidneys convert compounds into water soluble compounds
What is meant by the gluconeogenesis function of the kidneys?
the kidneys want to convert amino acids to glucose in the fasting mode
Why is it important to maintain Na+ and K+ homeostasis?
- to maintain normal blood pressure
- to maintain a normal resting membrane potential
What can happen if K+ concentration gets too high?
it can lead to hyperkalemia which can cause death
