Physiology Flashcards
What vessels deliver blood to the kidney?
Afferent arteriole
What does the efferent arteriole contain?
The blood that was not filtered through the glomerulus; contains plasma proteins.
What percentage of our body is made up of water?
60% in men
50% in women
How much of the body is ICF and how much is ECF?
ICF = 67% ECF = 33%
What tracer can be used to measure total body water?
Labelled H20
What tracer can be used to measure ECF volume?
Inulin
What tracer can be used to measure plasma volume?
Labelled albumin
What are the two components of the kidney?
Vascular and tubular
What are the two capillary networks in the kidney and what do they each do?
Glomerulus. Brings blood to be filtered by the kidney
Peritubular capillaries. Nourish the renal tissue.
What force favours filtration?
Glomerular capillary blood pressure
What forces oppose filtration?
Plasma osmotic pressure
Bowmans capsule hydrostatic pressure
Is sodium concentration greater in the ECF or ICF?
ECF
Is pottassium concentration greater in the ICF or ECF?
ICF
Is chloride concentration higher in the ECF or the ICF?
ECF
What are the two components of the ECF?
Plasma and interstitial fluid
What is a cation?
positive ion
What is an anion?
Negative ion
What happens to the osmolarity of the ECF and the ICF if there is a gain of water?
Osmolarity of both the ICF and the ECF will decrease
What happens to the osmolarity of the ECF and `ICF if there is an increase in sodium concentration in the ECF?
Osmolarity of ECF will increase but osmolarity of the ICF will decrease. No gain of sodium in the ECF and water drawn out which reduces osmolarity.
What is an average GFR?
125ml/min
What happens in the kidney when the blood pressure falls too low?
There is sympathetically induced afferent arteriolar vasoconstriction which decreases flow of blood into the glomerulus, lowering GFR.
What happens int he kidney when the blood pressure is raised?
There is a reduction is sympathetic activity and resultant vasodilation leading to an increased GFR.
What are the two types of nephrons? Which is more common?
Cortical - lie in kidney cortex
Juxtamedullary - glomeruli lies in inner cortex, next to the medulla.
What part of the juxtamedullary nephrons actually lie in the medulla?
Loop of henle
What percentage of plasma that enters the glomerulus is filtered? ~
20%
Write an equation calculating how you would work out the filtration of substance X:
Xplasma x GFR
Write an equation calculating how you would work out the filtration of substance X:
Xurine x Volume of urine
Write an equation calculating the rate of reabsorption of substance X.
Rate of filtration of X - Rate of excretion of X
Write an equation calculating the rate of secretion of substance X.
Rate of excretion of X - rate of filtration of X
What is the average glomerular capillary blood pressure?
55mmHg
What is the average capillary oncotic pressure?
30mmHg
What is the average bowmans capsule hydrostatic pressure?
15mmHg
What is the average bowmans capsule oncotic pressure?
0mmHg
What is the major force that induces glomerular filtration?
Glomerular capillary blood pressure
Is glomerular capillary blood pressure higher or lower than blood pressure in other capillaries?
Higher
What is Kf in relation of the glomerulus?
The filtration coefficient which is an assesment of how “holey” the glomerulus is.
What is the equation to work out GFR?
Kf x net filtration pressure
