Renal Physiology Flashcards
What are the functions of the Kidney ?
- Removal of waste products
- Regulating blood volume and pressure;
- pH and electrolyte composition;
- Stimulation of erythropoiesis (production of red blood cells);
- Supportingvit D biosynthesis
What is the role of the neprhon ?
Filtration
Reabsorption Active/ Passive
Secretion Active/ Passive
End result: Excretion
Why do you need to pee more in the cold?
Kidney perfusion increases
Is your Glomerular Filtration purely dependant on Blood pressure and perfusion?
no
What pressure pushes fluid out of the arteriole ?
Hydrostatic pressure
What pressure pushes fluid into the arteriole?
Osmotic pressure
What is Glomerular Filtration dependant on ?
Hydrostatic pressure
Oncotic pressure
Vasoconctriction/vasodilation of the arterioles.
and OSMOSIS.
Where does 70% of reabsoprtion occur within the kidneys ?
Proximal convoluted tubule
Which is the only region of the nephron able to permit the reabsorption of glucose ?
Proximal Convoluted Tubule
Explain Acid Base balance Renal compensation
CO2 + H20 <-> H2C03 <-> HCO3- + H+
- More H+ in blood- lower the pH (acidosis)
- H+ secreted into the urine (lost to blood); Bicarbonate reabsorbs (increases in blood)
- PH increases in blood
What is this
pH 7.2
CO2 7 kPa
O2 7 kPa
HCO3 34 mmol/l
respiratory acidosis with uncompensated metabolic alkalosis ?? i think
increased bicarbonate means that the body is throwing out hydrogen ions to the kidneys !
What is this ?
pH 7.55
CO2 2 kPa
O2 18 kPa
HCO3 24 mmol/l
uncompensated respiratory alkalosis
Patinet in extreme pain, kidney has no time to compensated (because this takes days).
Manegement is to give the patient pain reflied and this will resolve.
Where does the majority of water get reabsorbed ?
Loop of henle
How does Loop diuretics work ?
Side effects of loop diuretic ?
What happens in the distal convoluted tubule ?
Secretion of ions into the filtrate (K+)
Ca reabsorbtion
What happens in the collecting system ?
Some H+ secretion
ADH controlled H2O reabsorbtion
What is the difference between secretion and excretion?
Where does Thiazides work ?
DCT
What are thiazides used for ?
HTN
Where do K sparing diuretics work ?
Collecting tubule
Side effects of K-sparing diuretics?
Side effects of Thiazide diuretics?
What is GFR
Glomerular filtration rate
hard to estimate so we often use EGFR
What is EGFR
Estimated Glomerular filtration rate
What is the difference between nephritic and nephrotic syndrome ?
CASE STUDY
- Increase low osmolality fluid in serum
- Inhibition of ADH (Vasopressin)- decreases urine concentration
- Urine potassium wasting. If there is a low magnesium within the body then there will be an increase in potassium lost therefore magnesium may need to be replaced.
Explain Renin-angiotensin system
What is secondary hypertension ?
SECONDARY TO SOMETHING ELSE
What is cushings syndrome ?
Excess steroids eg doctors giving too much
What is Phenochromocytoma
Type of tumour that causes adrenaline
What is Aortic coarctation ?
Coarctation of the aorta is a birth defect in which a part of the aorta is narrower than usual.
How do ACE inhibitors work?
Block the ACE enzyme within the lung
How do Beta Blockers work?
B1 and B2
B1 - There is some effect on the kidney as it inhibits renin release but this is usually mild.
How do calcium channel blockers work ?
Therefore, blood pressure will go down because its reduces peripheral resistance.
how does erythropoietin respond to hypoxia ?
When you have hypoxia more erthrypotein is produced.
What does thrombopoietin produce ?
Platelets
Activation of vitamin D and maintenance of bone density?
CKD patients will be anaemic with low Vitamin D
However, their Platelets are usually normal. Why?
Thrombopoietin is not effected because it comes from the liver, kidney and spleen, where erythropoietin is produced primarily from the kidney.
