UW Madison Phys 335 Exam 4
1. regulation of water, ion balance and acid/base
balance -> controls BP
2. removal of waste products to create urea
3. removal of foreign chemicals
functions of renal system 4. glucogenesis (making glucose from amino
acids during fasting)
5. production of erythropoietin (production of
RBC) and renin (controls water balance/volume
of blood) and vitamin D to build bone
outer layer of kidney, contains blood vessels
contains renal corpuscles for both types of
renal cortex nephrons, convoluted tubules and cortical
nephrons
contains cortical collecting duct, JGA
inner layer of kidney, contains long loops of
henle and collecting ducts. juxtamedullary
renal medulla nephrons are in here
contains medullary collecting duct
nephron functional unit of the kidney
where blood is filtered, surrounds glomerular
bowman's capsule
capillaries
renal corpuscle glomerulus capillaries + Bowman's capsule
15% of all nephrons
long loops of henle go into renal medulla
juxtamedullary nephrons creating a concentration gradient which is
important for H2O reabsorption
contains vasa recta as peritubular capillaries
vasa recta peritubular capillaries in juxtamedullary
nephrons
maintains ISF gradient, returns reabsorbed water
and solute to circulation without washing out
gradient, solutes are trapped in medulla
descending- water moves out, solutes move in
, ascending- water moves in, solutes move out
85% of nephrons, short or no loops of henle so
only in renal cortex
cortical nephrons
doesn't add to concentration gradient /
hypertonic medullary interstitium
regulation of ion and water balance, controls BP
juxtaglomerular apparatus (JGA) composed of juxtaglomerular cells and macula
densa
near distal convoluted tubule, specialized
macula densa
epithelial
comes from vasomotor system
sympathetic nerve fiber in JGA constricts afferent arterioles and causes renin
secretion from JG cells
first step in urine formation, 20% of plasma is
glomerular filtration
filtered into tubule via bulk flow
second step in urine formation, movement of
tubular secretion
plasma from capillary to lumen of tubule
third step in urine formation, movement of
tubular reabsorption
plasma from tubule to capillary
1 (glomerular filtration) + 2 (tubular secretion) -
Equation for urinary excretion
3 (tubular reabsorption)
what substance is described?
drugs, toxins (waste products)
20% freely filtered and then 100% secreted
what substance is described?
Na+, Cl-, water (drink more, reabsorb less)
20% freely filtered and then partially reabsorbed
which substance is described?
glucose, amino acids
20% freely filtered and then 100% reabsorption
between glomerular capillaries and bowman's
capsule
1. capillary endothelium (leaky pores which are
glomerular filtration barrier layers called fenestraé and are like windows)
2. basement membrane (negatively charged,
excludes plasma proteins)
3. bowman's epithelium (podocytes)
glomerular filtration rate (GFR) volume of fluid filtered from glomeruli into
bowman's space per unit time
, average = 125 ml/min aka 180 L/day (filtered 60
times per day)
glomerular capillary blood pressure
Pgc
normally 60mmHg
fluid pressure in bowman's space
normally 15mmHg
Pbs
opposes filtration, goes from bowman's space to
glomerular capillary
osmotic force due to protein in plasma
normally 29 mmHg
piGC
opposes filtration, goes from bowman's space to
glomerular capillary
Pgc - Pbs - PIgc
net glomerular filtration pressure
normally 16 mmHg
what happens to GFR when afferent arteries are
it decreases
constricted?
what happens to GFR when efferent arteries are
it decreases
dilated?
what happens to GFR when efferent arteries are it increases
constricted? like a dam
what happens to GFR when afferent arteries are it increases
dilated? caffeine does this
what happens to starling forces and net increase in Pbs
glomerular filtration pressure with a kidney
stone? decrease in Pgc
filtered load GFR x plasma concentration
filtered + secreted - reabsorbed
excreted load
V x urine concentration
what happens when EL < FL? net reabsorption
what happens when EL > FL? net secretion
how much of filtered volume is reabsorbed? 99%
tubular reabsorption 1. diffusion of lipid soluble (hydrophobic)
substances that don't need carriers
1. regulation of water, ion balance and acid/base
balance -> controls BP
2. removal of waste products to create urea
3. removal of foreign chemicals
functions of renal system 4. glucogenesis (making glucose from amino
acids during fasting)
5. production of erythropoietin (production of
RBC) and renin (controls water balance/volume
of blood) and vitamin D to build bone
outer layer of kidney, contains blood vessels
contains renal corpuscles for both types of
renal cortex nephrons, convoluted tubules and cortical
nephrons
contains cortical collecting duct, JGA
inner layer of kidney, contains long loops of
henle and collecting ducts. juxtamedullary
renal medulla nephrons are in here
contains medullary collecting duct
nephron functional unit of the kidney
where blood is filtered, surrounds glomerular
bowman's capsule
capillaries
renal corpuscle glomerulus capillaries + Bowman's capsule
15% of all nephrons
long loops of henle go into renal medulla
juxtamedullary nephrons creating a concentration gradient which is
important for H2O reabsorption
contains vasa recta as peritubular capillaries
vasa recta peritubular capillaries in juxtamedullary
nephrons
maintains ISF gradient, returns reabsorbed water
and solute to circulation without washing out
gradient, solutes are trapped in medulla
descending- water moves out, solutes move in
, ascending- water moves in, solutes move out
85% of nephrons, short or no loops of henle so
only in renal cortex
cortical nephrons
doesn't add to concentration gradient /
hypertonic medullary interstitium
regulation of ion and water balance, controls BP
juxtaglomerular apparatus (JGA) composed of juxtaglomerular cells and macula
densa
near distal convoluted tubule, specialized
macula densa
epithelial
comes from vasomotor system
sympathetic nerve fiber in JGA constricts afferent arterioles and causes renin
secretion from JG cells
first step in urine formation, 20% of plasma is
glomerular filtration
filtered into tubule via bulk flow
second step in urine formation, movement of
tubular secretion
plasma from capillary to lumen of tubule
third step in urine formation, movement of
tubular reabsorption
plasma from tubule to capillary
1 (glomerular filtration) + 2 (tubular secretion) -
Equation for urinary excretion
3 (tubular reabsorption)
what substance is described?
drugs, toxins (waste products)
20% freely filtered and then 100% secreted
what substance is described?
Na+, Cl-, water (drink more, reabsorb less)
20% freely filtered and then partially reabsorbed
which substance is described?
glucose, amino acids
20% freely filtered and then 100% reabsorption
between glomerular capillaries and bowman's
capsule
1. capillary endothelium (leaky pores which are
glomerular filtration barrier layers called fenestraé and are like windows)
2. basement membrane (negatively charged,
excludes plasma proteins)
3. bowman's epithelium (podocytes)
glomerular filtration rate (GFR) volume of fluid filtered from glomeruli into
bowman's space per unit time
, average = 125 ml/min aka 180 L/day (filtered 60
times per day)
glomerular capillary blood pressure
Pgc
normally 60mmHg
fluid pressure in bowman's space
normally 15mmHg
Pbs
opposes filtration, goes from bowman's space to
glomerular capillary
osmotic force due to protein in plasma
normally 29 mmHg
piGC
opposes filtration, goes from bowman's space to
glomerular capillary
Pgc - Pbs - PIgc
net glomerular filtration pressure
normally 16 mmHg
what happens to GFR when afferent arteries are
it decreases
constricted?
what happens to GFR when efferent arteries are
it decreases
dilated?
what happens to GFR when efferent arteries are it increases
constricted? like a dam
what happens to GFR when afferent arteries are it increases
dilated? caffeine does this
what happens to starling forces and net increase in Pbs
glomerular filtration pressure with a kidney
stone? decrease in Pgc
filtered load GFR x plasma concentration
filtered + secreted - reabsorbed
excreted load
V x urine concentration
what happens when EL < FL? net reabsorption
what happens when EL > FL? net secretion
how much of filtered volume is reabsorbed? 99%
tubular reabsorption 1. diffusion of lipid soluble (hydrophobic)
substances that don't need carriers
