A&P final Flashcards
Roles of the kidneys:
- manager of blood pressure
- manger of pH
- hematocrit
- electrolyte regulator
- Vitamin D regulator
- long term blood glucose levels manager
- some drug clearance
- LT metabolic waste disposal
- osmolarity regulator
if someone has long term High blood pressure then something is wrong with their
kidneys
kidney’s roles in managing pH
- decides how much HCO3- to get rid of
- source of HCO3-
- in charge of getting rid of excess protons
what is the short term pH regulator system?
the lungs
- They get rid of CO2 which helps lower the pH but they cannot get rid of excess protons
How do the kidneys help control the hematocrit?
The deep medullary structures in the kidneys detect low Oxygen levels and releases erythropoietin (EPO) which acts to stimulate the bone marrow to increase RBC production. This should fix the low oxygen problem and increases HCT.
Why is it that you are thirsty a couple of hours after eating a pizza?
The intestines just reabsorbs all the Na+. The kidney has to excrete it.
How do we maintain Ca++ levels via the kidneys?
The kidneys choose how much to reabsorb.
They also kidney activate Vit. D to help us absorb Ca++ from the food we eat
What is the kidneys role in managing long term glucose levels?
The more we filter the more we reabsorb. If BG is a high then the kidney reabsorbs it.
But if BG is really high for a long time (like 900) then it is way higher than the transport/reabsorption max so the kidney’s get rid of it
What is the safety or blow off valve when we have really high blood glucose levels?
the kidney
The kidney doesn’t process many drugs, but when it does, how does it work?
secretory process
A pt. that has long term severe diabetes, what do they produce besides glucose that the kidney is in charge of clearing?
Nitrogenous products like urea
How does the body regulate osmolarity?
by choosing to hang on to or get rid of salt and/or water
If NaCl is high in the body then kidney regulates this by:
get rid of salt and hold onto water
The kidney has the ability to _______ between sodium and water and therefore can pick and choose what to get rid of and what to hold on to. What is this regulated by?
differentiate
ADH and osmoreceptors in the brain
What is the order of the renal blood vessels from renal arteries to renal veins?
renal artery
—split—
segmental arteries
interlobar arteries
arcuate arteries
interlobular arteries
afferent arterioles
glomerular capillaries
efferent arterioles
peritubular capillaries
—converge—
interlobular veins
arcuate veins
interlobar veins
segmental veins
renal veins
What is the purpose of the tubular system
To reabsorb stuff that has been filtered and to secrete things to get rid of in the urine
What is a collection of blood vessels plus the tubular capillaries?
a nephron
How many nephrons do you have at birth?
2 million
1 million in each kidney
At what age do you start to lose nephrons?
40 yr/old
What is the basic functional unit of kidney?
nephron
What are the 2 types of nephrons?
superficial nephrons
deep nephrons -medullary nephrons
about ____% of nephrons are cortical
90-95%
what % of neprhons are deep medullary neprhons?
5-10%
The top of the cortical nephrons will be in the _______
cortex
The deeper peritubular capillaries and tubules that are associated with those are where in the nephron?
They dip into the outer part of the medulla
Are there a lot of peritubular capillaries of the deep medullary nephrons(vasa recta)?
not as many as the peritubular capillaries of the cortical nephrons
One feature of the of the deep medullary peritubular capillaries(vasa recta)?
They have an unequal number of descending and ascending capillaries. The ascending capillaries split into multiple but the descending capillaries stay whole.
What is the purpose of the split in the ascending capillaries in the deep medullary capillaries (vasa recta)?
Velocity of blood through the ascending blood vessels is slower which is important to maintain a normal number of solutes in the deep interstitium of the renal medulla.
If flow is too fast it will “wash out” the renal interstitium. if you change the concentration of the interstitium this would effect reabsorption.
name of deep medullary capillaries
vasa recta
Blood vessels are in charge of delivering nutrients to tissues. Why don’t we have any issue delivering oxygen and nutrients to the cortical nephrons vs the deep medullary nephrons?
the deep medullary nephrons only have 5-10% of the vessels. Less vessels= less blood
why are the deep medullary nephrons very sensitive low blood pressure?
d/t the limited number of peritubular capillaries. Only 5-10% of the renal peritubular capillaries
what does DVR and AVR stand for?
descending and ascending vasa recta
Where are the kidneys housed?
right under the diaphragm
What are the renal arteries and veins below?
right below the mesenteric arteries
What is seated on top of each of the kidneys?
adrenal glands
What are the ureters?
collection system of whatever fluid is left over in the tubules that needs to be removed from the body.
what is the purpose of the bladder?
to store urine
what is a suprarenal gland?
adrenal glands
first part of urine emptying system
renal papilla
The top lateral part of the right kidney comes in contact with the?
Lower lateral part of the right kidney comes into contact with the?
liver
colon
The top part of the left kidney comes in contact with the ____?
What is the name of this area of the kidney?
stomach
gastric surface
The top lateral part of the left kidney comes in contact with the ____?
spleen
The colon comes into contact with which kidney?
Both left and right
Why does it matter what is touching the kidneys?
Cancer can spread very easily to things that are in close proximity of it
Why is cancer less likely in the kidneys?
the nephrons die off as you get older, they do not proliferate quickly.
Heart also doesn’t proliferate quickly which is why you don’t really hear about heart cancer
Which abdominal quadrant are the kidneys in?
right upper quadrant
left upper quadrant
The minor calyx come together to form what?
the ureter
what does the ureter empty into?
where does that empty through?
bladder
urethra
where can kidney stones happen?
calyx
ureter
bladder
urethra
Where does it hurt when you have a kidney stone?
lower back
most kidney stones pass on their
own
difference between men and women’s urethra
men: gland surrounding urethra called the prostate
women: shorter urethra
problems with the prostate as men get older:
cancer
prostate enlargement
why do older men have to go to the bathroom frequently?
have a hard time emptying bladder d/t constriction in the prostate.
nearly impossible to completey empty bladder only overflow can be emptied
what controls the bladder?
SNS and PNS both.
Can lose control of our bladder or can find it difficult to empty the bladder when nervous
Control of the emptying of the bladder is typically a function what nerve?
pudendal nerve
What spinal nerves do the Pudendal nerve come from?
S2
S3
S4
which nerve controls the solid waste excretion?
Pudendal nerve
It is important to keep things intact at spinal nerves ________ if you want to keep things off the floor in the OR
S2
S3
S4
Which nerve runs very close to the prostate gland?
Pudendal nerve
removal of the gland is easy but pudendal nerve can get cut inadvertently
what is responsible for erections in men?
pudendal nerve
Bowman’s capsule is also known as
corpuscle
Order of the kidney tubule:
Corpuscle/ Bowman’s capsule
Proximal Convoluted Tubule
Proximal Straight Tubule
Descending Thin Limb of Henle
Ascending Thin Limb of Henle
Thick Ascending Limb
–Macula Densa
Distal Convoluted Tubule
Connecting Duct
Cortical Collecting Duct
outer Medullary Collecting Duct
inner Medullary collecting duct
papillary duct
what is located in the Thick ascending limb that tells the kidney how much fluid is being filtered?
Macula Densa
a “speedometer”
Where in the loop of Henle is the macula Densa?
TAL in the loop of Henle
some books say DCT
which comes into contact with the afferent and efferent arterioles that controls GFR?
macula densa
difference between the oMCD and iMCD
more superficial
very deep
which cells sit next to the afferent and efferent arterioles in the kidney
and detect blood flow ?
juxtaglomerular cells
what is released from the juxtaglomerular cells at the afferent and efferent arterioles when pressure is sensed to be low?
renin
what does renin do?
eventually increases angiotensin II which preferentially constricts the efferent arteriole which increases pressure in the capillaries which increases filtration which restores flow to something that looks more normal.
What happens when the juxtaglomerular cells sense that flow is too high?
Less renin is released which vasodilates the efferent arteriole to decrease pressure in the glomerular capillaries
associate angiotensin II with
something that controls the juxtaglomerular apparatus
Famous guy with prostate cancer and why he was famous:
Linus Pauling
He was a chemist and was a huge proponent of taking vit. c to slow down or prevent cancer. He ended up living a long time.
strong enough antioxidant can slow down or prevent:
cancer
free radical oxidative stress studies looked at what compounds?
vit. C
They were inconclusive
How much Vit. C did Linus Pauling take every day?
20,000 units vit. C a day
what is renal clearance
quantity of a plasma that is cleared of a substance per time
mL/min
volume/time
If the kidneys reabsorbs a lot of fluid and does not reabsorb the stuff in the fluid then renal clearance is
high
if kidney reabsorbs a lot of fluid and all of the things in the fluid then renal clearance for that compound is
low
A dot over the top of a V is the symbol for
Volume per unit of time.
What symbol is used for urine volume/min?
A U with a dot over it.
Same thing as a V with a dot over it
What are the characteristics of something that is easily filtered
smaller than a protein
positive charge or no charge
What would the concentration in the tubule look like compared to the plasma, if you have a compound that is smaller than a protein and positively charged or has no charge?
should look about the same as the plasma before it was filtered.
If there’s no impediment to filtering the compound then the concentration in the Bowan’s capsule should look like the concentration at the top of the tubule.
About ______ of almost everything gets reabsorbed at the pct
2/3
Glucose has no problem being filtered from the glomerular capillary into the tubule because it is
small and uncharged
If there is none of the substance you are filtering in the urine, then the clearance would be ______
What compound should do this?
0
glucose. There are transporters that pull all of it back into the cardiovascular system.
If you have a compound X that is filtered freely at the glomerular capillaries into the tubule but you don’t reabsorb any of it, how much plasma can be reabsorbed into the CV system? what is this called?
How much fluid/min is excreted?
124mL/min
clearance rate
1mL/min
If you have a compound X that is filtered freely at the glomerular capillaries into the tubule but you don’t reabsorb any of it, what concentrations would you expect to see:
1. early on in the tubule
- later on as reabsorption happens
- in the collecting duct
- same as plasma
l. high since we are actively reabsorbing water but none of the compound.
3.a very high concentration. All of the compound is now in 1mL of fluid
If you have a compound X that is filtered freely at the glomerular capillaries into the tubule but you don’t reabsorb any of it, what concentrations would you expect to see in the efferent arteriole?
There shouldn’t be much of a change from the plasma because nothing selectively left it behind in the capillaries.
If you have a compound X that is filtered freely at the glomerular capillaries into the tubule but you don’t reabsorb any of it, what concentrations would you expect to see in the peritubular capillaries?
a very diluted solution because the reabsorbed solution doesn’t have any compound x so the only compound x that makes it to the peritubular capillaries is what snuck through the glomerular capillaries without being filtered.
If you have a compound X that is filtered freely at the glomerular capillaries into the tubule but you don’t reabsorb any of it, you would you expect to see a lower concentration of compound in the renal ______ vs renal______
vein vs artery
- If the concentration of compound X in the plasma is 1mg/dL
- If X is freely filterable
- How much of compound X did I filter?
- what is the concentration of X in the urine? This is also called the excretion rate.
Filtration rate: 125mL/min=1.25dL/min
Concentration is 1mg/1dL
You filtered 1.25mg/min
Qty removed or concentration in the urine is 1.25mg/1mL/min urine
what is a dL in mL?
100mL
If you have filtration with no reabsorption or secretion, the clearance rate should be about the same as our?
GFR
GFR is 125mL/min
Kidney reabsorbs (clearance) 124mL/min
the rest is excreted.
solve for clearance to estimate our GFR
V= 1mL/min
Ux=1.25mg/mL
Px=1mg/100mL
C=VU/P
1.25mg/min/1mg/100mL
1.25mg/min X 100mL/1mg
clearance=125mL/min
clearance=
Cx=
(V*Ux)/Px
urinary flow rate normal is 1ml/min X urinary concentration this is the excretion rate / plasma concentration
compound X represented
inulin
What is the gold standard for figuring out GFR?
inulin.
Exogenous compound the kidneys cannot reabsorb and does not secrete.
given iv. let time pass. take 2 measurements to look at urinary plasma concentration at time A and B and then extrapolate GFR
Why is in inulin better than cr?
inulin doesn’t get reabsorbed or secreted where Cr gets secreted. This would mean using Cr would give us an overestimation of GFR
what is cr
a biproduct of skeletal muscle metabolism
if you have an old patient who hasn’t gotten out of bed in a long time how does this effect Cr?
Cr is low
Cr gives an artificially ______ GFR
high
If you have a compound Y that is filtered freely at the glomerular capillaries into the tubule and is then highly secreted, what concentrations would you expect to see in the:
- tubule
- peritubular capillaries
- a highly concentrated amount from everything that was filtered plus secreted
- little to no compound y if the pump is secreting 99-100% of compound Y back into the tubule
formula for secretion rate
secretion rate=excretion rate-filtered load
mg/min
If you have a compound Y that is filtered freely at the glomerular capillaries into the tubule and is then highly secreted, then the really clearance rate is ______ and is equivalent to
very high
renal plasma flow
if you know what renal plasma flow is and you have a Hct, you can figure out
renal blood flow
compound Y is
PAH
Glomerular filtration rate equation
GFR= Uinulin X V/ Pinulin
no unit?
Clearance ratio equation
Clearance ratio= Cs /Cinulin
no unit
Effective renal plasma flow formula
ERPF=CPAH=UPAHXV
mL/min
formula to convert Renal Plasma Flow to Renal Blood Flow
RBF=RPF/1-Hematocrit(usually 0.4)
mL/min
What % of the PAH does the kidney normally pull out?
90%
excretion rate
Us X V
mg/min
Formula for reabsorption rate
Reabsorption rate=(GFRXPs)-(U X V)
mg/min
The top middle part of the left kidney comes in contact with the ____?
pancreas
