Renal Flashcards
the cortex is ___osmotic
iso (300 mosm)
the medulla is ____osmotic
hyper (over 300 mosm)
what are the two types of nephron?
cortical, juxtamedullary
what percent of nephrons are cortical?
80
what percent of nephrons are juxtameduallary?
20
what type of nephron is responsible for reabsorption from plasma?
cortical
what type of nephron is responsible for water balance and urine concentration?
juxtameduallary
___ ____ cells sense ions
macula densa
_____ cells sense blood pressure/mean arterial pressure
juxtaglomerular
what two cells compose the juxtaglomerular apparatus?
macula densa, juxtaglomerular
what type of cells line the distal tubule?
macula densa
what type of cells line the afferent arteriole?
juxtagomerular
what is the primary determinant of filtration?
glomerular capillary hydrostatic pressure (mmhg)
what two things promote filtration?
glomerular capillary hydrostatic pressure, bowman’s space onconic pressure
RBC are ____ in the capillary
kept
large proteins are ____ in the capillary
kept
Bowman’s space oncotic pressure is related to ____ content
protein
Bowman’s space oncotic pressure should be ___
0
what two things oppose filtration?
plasma oncotic pressure, Bowman’s space hydrostatic pressure
what are the three layers of the filtrating membrane?
fenestrated endothelial cells, podocytes, basement membrane
what things are filtered from the glomerular capillaries?
ions, water, small molecules (glucose, amino acids), drugs
the basement membrane is ___ charged
negatively
what is the role of the basement membrane?
prevent proteins or RBC from entering
what is the barrier that is the last defense of filtration?
podocytes
the glomerular filtration rate (GFR) is a measure of what?
kidney function
the ___ ____ ____ is the amount of filtrate formed per minute
glomerular filtration rate
what is the average GFR?
120-125 mL/min
how many times is blood filtered per day?
45
what will this do to GFR? vasoconstriction of efferent arteriole
increase
what will this do to GFR? vasodilation of afferent arteriole
increase
what will this do to GFR? vasoconstriction of afferent arteriole
decrease
what will this do to GFR? vasodilation of efferent arteriole
decrease
as you decrease Pgc, you _____ GFR
decrease
as you increase Pgc, you ___ GRF
increase
if you increase mean arteriole pressure, afferent arterioles ____
constrict
if you decrease mean arteriole pressure, afferent arterioles ____
dilate
tubulogomerular feedback is a ___ loop
negative
what is the input/afferent path in the tubulogomerular feedback loop?
Na, Cl, H2O
what is the control center in the tubulogomerular feedback loop?
juxtaglomerular cells
what is the output/efferent path in the tubulogomerular feedback loop?
decrease in nitric oxide
what is the role of nitric oxide?
vasodilation
low GFR and low MAP is what medical condition?
hypotension
high GFR and high MAP is what medical condition?
hypertension
what is the healthy range for MAP?
80-120
if your blood pressure increased, GFR _____ to get rid of fluid
increases
what hormone is responsible for increases GFR when blood pressure is high?
atrial natriuretic peptide (ANP)
when blood pressure is high, the atrial stretch and ___ is released
ANP
if blood pressure is decreased, GFR ____ to save fluid
decreases
what ways do kidneys regulate blood?
ionic composition, pH, blood volume, MAP, osmolarity
what hormone released from the kidneys increases number of RBCs?
erythropoetin
what hormone released from the kidneys regulates calcium levels?
active vitamin D
what hormone released from the kidneys increased MAP?
renin
cell concentrations of Na
ECF: 145 ICF: 15
cell concentrations of K
ECF: 5 ICF: 150
cell concentrations of Cl
ECF: 100 ICF: 7
RBCs are ___% of blood
40
the concentrations of ions (Na,K,Cl) in the blood plasma are the same as where?
interstitial space
plasma is ___% of blood
60
what is the name of the kidney hormonal process that regulates blood pressure?
Renal Angiotensin Aldosterone System (RAAS)
changes in blood pressure are detected by _____ cells
juxtaglomerular
____ is released from the kidney when low blood pressure is detected by juxtaglomerular cells
renin
____ in the first hormone released from the liver
angiotensinogen
____ causes the conversion of angiotensinogen to angiotensin 1
renin
where is angiotensin 1 converted into angiotensin 2?
blood vessels
what in the blood vessels converts angiotensin 1 to angiotensin 2?
angiotensin converting enzyme
what is the active enzyme of the liver?
angiotensin 2
angiotensin 2 acts on ___ ___ in the CV system
smooth muscle
what three things occur when blood pressure decreased and angiotensin 2 acts on the CV system?
increase vasoconstriction, decrease radius, increase resistance
when angiotensin 2 acts on the adrenal gland, what hormone is released?
aldosterone
aldosterone released from the adrenal gland is sensed by what in the kidneys?
macula densa cells
what occurs in the kidney when aldosterone is released from the adrenal gland and sensed by macula densa cells?
increase salt retention, increase water retention
what does aldosterone do to the K concentration in kidneys?
more excretion, greater urine output
what can occur if K concentration is too high in the plasma?
improper activity, irregular heart beats, difficulty repolarizing
does glucose make blood more basic or acidic?
acidic
what substances can be found in filtrate?
water, Na, K, Cl, Ca, H+, HCO3-, glucose
what substances are not found in filtrate?
RBCs, large proteins
___ ____ is when blood plasma moves from the glomerular capillaries into Bowman’s capsule
glomerular filtration
______ ______ is when substances move from Bowman’s capsule back to the capillaries and useful molecules such as glucose and bicarbonate are returned
tubular reabsorption
____ _____ is substances moving from the capillaries into the proximal tubule
tubular secretion
what are the 3 tasks of urine production?
glomerular filtration, tubular reabsorption, tubular secretion
at rest, kidneys have ___L of cardiac output
1
what are the 2 routes of reabsorption?
peracelluar, transcellular
what substances are reabsorbed via peracellular reabsorption?
ions, water
what substances are reabsorbed via transcellular reabsorption?
water (osmosis)
____ of water is reabsorbed into the kidneys
2/3
peracelluar reabsorption occurs through ___ ____
tight junctions
transcellular reabsorption uses ____ to transport water through the cell
aquaporins
reabsorption of glucose and single amino acids involves __-____
co-transport
what is transported with glucose and single amino acids?
Na
what is the name of the system that reabsorbs H+ and HCO3-?
carbonic anhydrase system
what is the role of the carbonic anhydrase system?
maintain body pH at 7.2-7.4
how does water enter the carbonic anhydrase system?
aquaporins
how is H+ secreted from the carbonic anhydrase system?
sodium/hydrogen exchanged
what is transferred into the epithelial cell when hydrogen is secreted out?
Na
how does sodium leave the epithelial cell in the carbonic anhydrase system?
NA/K ATPase
how does HCO3- (bicarbonate) leave the epithelium to be reabsorbed into the capillaries?
bicarbonate transporter
as you decrease blood pH, you ____ CO2 production
increase
what is the enzyme that converts H2O and CO2 into H2CO3?
carbonic anhydrase
the ____ tubule is the workhorse
proximal
____% of solutes are reabsorbed
65
___% of water is reabsorbed
65
____% of organic solutes are reabsorbed (i.e. glucose, amino acids)
100
____% of HCO2- is reabsorbed
80-90
where does the secretion of drugs and acids occur?
proximal tubule
most transport in the proximal tubule is coupled with what molecule?
Na
drugs are secreted from the proximal tubule via ___ ____
active transport
where is the proximal tubule located?
cortex
____ is a measure of the volume of plasma over time that is cleared of a particular substance
clearance
clearance is defined in terms of ___ ____
blood plasma
each substance has it’s own ___ value
clearance
what is calculated by (urine flow*urine concentration of substance)/plasma concentration of substance
clearance
if the substance is reabsorbed, clerance is ___ ___ GFR
less than
if the substance is secreted, clearance is ___ ___ GFR
greater than
what is the best, most accurate calculator of GFR?
inulin
inulin is freely ____ and not ___
filtered, secreted
____ is the most practical measure of GFR
creatinine
how is creatinine produced?
break down of creatine phosphate from muscle
creatinine is freely _____ and not ____
filtered, reabsorbed
creatinine is slightly ____
secreted
when there is no secretion and no reabsorption, clearance ____ GFR
equal
when there is secretion and no reabsorption, clearance is ____ ____ GFR
greater than
when there is reabsorption and no secretion, clearance is ___ ____ GFR
less than
what substances have clearance greater than GFR?
H+ ions, drugs, toxins
what substances have clearance less than GFR?
glucose, amino acids, Na+, HCO3-
water gained:
___% metabolism
___% food
__% liquids
10%, 30%, 60%
water lost:
___% feces
____% lungs
____% skin
_____% urine
5%, 10%, 25%, 60%
____ nephrons are the ones most involved in water balance
juxtaglomerular
urine becomes ___ concentrated as it travels down the descending loop because water is being removed
more
urine becomes ____ concentrated as it travels up the ascending loop
less
what is transferred out of urine in the thick ascending limb?
Na, K, Cl
the ___ ____ ____ has a Na/K/Cl symporter
thick ascending loop
what is the target of diuretics?
Na/K/Cl symporter in the thick ascending limb
the Na/K/Cl symporter is ____ by diuretics
blocked
what is the final goal of diuretics?
keep water in urine
how does Na leave the thick ascending loop into capillaries?
Na/K ATPase
how does K leave the thick ascending loop into capillaries?
leak K channels
How does Cl leave the thick ascending loop into capillaries?
Cl- channels
___ is cycled between the nephron and collecting duct to keep osmolarity high in the medulla
urea
urea helps keep osmolarity ___ in the medulla
high
the trapping of ____ and ____ in medulla keeps it hyperosmotic
Na, Cl
what is exchanged in the countercurrent exchange?
water, NaCl
the vasa recta runs along the ___ ____
basement membrane
vasa recta use ___ ____ to recirculate salt and urea
concentration gradients
a concentrated medulla helps save ___
water
what anti-diuretic hormones are involved in the cycling of the loop of Henle?
ADH, Vasopressin
when you are dehydrated, the plasma concentration of ADH is _____ and you ____the number of aquaporins in collection ducts
increase, increase
as you add aquaporins, the urine becomes more ____
concentrated
when you ingest excess water, plasma concentration of ADH _____ and the number of aquaporins ____
decreases, decreases
as you remove aquaporins, the urine becomes more ____
diluted
where is ADH released from?
posterior pituitary
what are the 3 roles of ADH?
water reabsorption at collecting duct, regulate osmolarity, act on principal cells in the collecting ducts
where are principal cells found?
collecting ducts
where is the area of calcium homeostasis?
early distal tubule
fine tuning occurs in the ___ ___ ___
late distal tubule
what type of distal tubule cells reabsorb sodium, secrete potassium, note aldosterone from adrenal gland
principal cells
what type of distal tubule cells maintain pH, reabsorb HCO3- (bicarbonate), and secrete hydrogen
intercalated cells
what two hormones regulate the distal tubule?
ADH, aldosterone
what regulated the proximal tubule?
concentration gradients
how does hormonal regulation via RAAS manage blood pressure?
volume of plasma and concentration changes of Na in plasma
what is the neural regulation of blood pressure?
baroreceptors
aldosterone is ___ lasting and ____ acting
long, slow
___ ____ reabsorbs HCO3- and secretes H+ in the proximal tubule
carbonic anhydrase
the ____ ____ pump is essential for pH balancing in the proximal tubule
hydrogen potassium
____ cell sense mean arterial pressure
juxtaglomerular
two ways to increase GFR
dilate afferent, constrict efferent
two ways to decrease GFR
constrict afferent, dilate efferent
_____ cells are what add aquaporins
principal
