renal regulation Flashcards
how do you control Glomerular Filtration Rate and Renal Plasma Flow
by controlling the resistance of the afferent arterioles
how do sympathetic nerves regulate RBF and GFR
sympathetic nerves bind to alpha 1 receptors on afferent arterioles causing vasoconstriction
overall causes RBF and consequently GFR
why is sympathetic nerve vasoconstriction important
it is an important response to hemorrhage to decrease RBF and consequently GFR
relationship between hydrostatic pressure of the glomerular capillaries and the afferent arteriolar resistance
inverse relationship
as the afferent arteriolar resistance goes up the hydrostatic pressure in the glomerular capillaries goes down and as a result globular filtration in reduced and as a result RBF is reduced in the efferent arteriole
relationship between hydrostatic pressure in glomerular capillaries and glomerular filtration rate and RBF in the efferent arteriole
direct relationship
as hydrostatic pressure in glomerular capillaries goes down, the glomerular filtration rate also goes down and as a result RBF is reduced in the efferent arteriole
how does AngII
regulate RBF and GFR
there is vasoconstriction of both the afferent and efferent arterioles
the efferent arteriole is more sensitive
overall this causes an increase in the glomerular filtration rate and a decrease in the RBF in the efferent arteriole
relationship between efferent arteriolar resistance hydrostatic pressure of the glomerular capillaries
directly related
as the efferent arteriolar resistance is increased the hydrostatic pressure of the glomerular capillaries is increased and therefore the glomerular filtration rate is increased
how do Prostaglandins (PGE2, PGI2)
regulate RBF and GFR
they cause a vasodilation
this acts as a protective measure (has a protective effect)
overall there is an increase in renal blood flow
as the affterent arteriolar resistance is decreased (vasodilated) the hydrostatic pressure of the glomerular capillaries is increased and therefore the glomerular filtration rate is increased
how does dopamine
regulate RBF and GFR
they cause a vasodilation
this acts as a protective measure (has a protective effect)
overall there is an increase in renal blood flow
as the affterent arteriolar resistance is decreased (vasodilated) the hydrostatic pressure of the glomerular capillaries is increased and therefore the glomerular filtration rate is increased
dopamine in shock
dopamine is administered during shock to increase RBF
which receptors does dopamine act on in order to vasodilator
D1 D3 and D5
afferent arteriole vasodilators
prostaglandins, dopamine, ANP and NO
NO
Nitric oxide
ANP
Atrial Natriuretic Peptide same this as Atrial Natriuretic Factor
Starling Forces Across Glomerular Capillaries
changes in glomerular filtration rates can be brought about by changes in any one of these strain forces
Pressure in Bowman’s capsule and glomerular filtration rates
as Pressure in Bowman’s capsule increases, the glomerular filtration rates decrease
vice versa
inversely related
Mean Arterial Pressure and glomerular filtration rates
as Mean Arterial Pressure in increases, the pressure in in the glomerular capillaries increases and the glomerular filtration rates increases
directly related
Oncotic pressure in the glomerular capillaries and glomerular filtration rates
as Oncotic pressure in the glomerular capillaries increases, the glomerular filtration rates decrease
vice versa
inversely related
Hydrostatic pressure in glomerular capillaries and glomerular filtration rates
favor
directly related
Oncotic pressure in glomerular capillaries and glomerular filtration rates
oppose
inversely related
Hydrostatic pressure in Bowman’s capsule and glomerular filtration rates
oppose
inversely related
Oncotic pressure in Bowman’s capsule and glomerular filtration rates
favor
directly related
small MW solutes in filtrate
All small-MW solutes appear in filtrate in the same concentrations as in blood plasma
GFR depends on the sum of the Starling forces across
across the capillary wall: forces favoring – forces opposing
