Pharm Test 3 Flashcards
what is a natriuretic?
something that gets rid of sodium
water follows
sodium
what are the main targets of diuretics?
- membrane transport proteins(most common)
- water permeable segments of nephrons (Osmotic diuretics)
- enzyme inhibition (Carbonic anhydrase)
- interference with hormone receptors (RAAS)
which diabetic drug can be used as a diuretic?
SGLT2 inhibitors
how do we get down excess ammonia?
we convert it to urea(made in the liver) and then excrete it through the kidneys
Macro anatomy of the urinary tract
renal artery, vein, and ureter exits through the hilum.
ureter comes from the kidney on both sides and connects with the urinary bladder.
the urethra comes from the bladder and exits the body
what is the outer portion of the kidney called?
cortex
what is the inner portion of the kidney called?
medulla (has medullary pyramids)
where does the nephron start?
at the bowman’s capsule
the medulla has a very different ______ than what is in the cortex. This effects how much water is going to be absorbed into the ureter vs. blood stream
osmolality
what is the primary function of the glomerulus?
filtration
most of what gets filtered in the glomerulus gets
reabsorbed later on
if the glomerulus can’t get rid of something, how does it exit the body?
it gets secreted in another area of the nephron
The renal corpuscle has what 2 components?
the outer component: the capsule. Called bowman’s capsule
the blood component: glomerulus. Efferent and Afferent arterioles
what comes after the bowman’s capsule?
the proximal convoluted renal tubule
what comes after the proximal convoluted renal tubule?
what are it’s different parts?
the Loop of Henle
Thick descending
thin descending
thin ascending
thick ascending
which part of the nephron is in the medulla?
loop of Henle
which part of the nephron is in the cortex?
everything above the loop of henle
what comes after the loop of henle? What does it dump into?
the distal convoluted tubule. dumps into the collecting tubules which turn into the collecting ducts as more and more tubules feed into it
If we see a lot of protein in the urine we would think
that something is wrong with the kidney
the distal tubule passes by the ________. Why is this important?
bowman’s capsule
The macula densa cells of the juxtaglomerular apparatus sense sodium delivery and overall fluid pressure and these can activate the RAAS system. Can also regulate the blood flow into the glomerulus directly by increasing or decreasing the size of the afferent arteriole.
where are glomeruluri ONLY found?
in the cortex
wrapped around the proximal distal convoluted tubules are the what? and what are the responsible for?
peritubular capillaries
secretion and reabsorption
What is the capillary system that wraps around the loop of henle? what is it responsible for?
vasa recta
osmolality changes, reabsorbing ions that are going to be taken back up into the medulla as opposed to the cortex
what are some things that the kidneys don’t want to secrete a bunch of?
bicarb
glucose
what percent of stuff that gets filtrated at the glomerulus gets secreted as urine?
1%
what is the juxtaglomerular apparatus?
a section of the distal convoluted tubule that has specialized cell types which are refered to as the macula densa. These monitor the osmolality.
what surrounds the afferent arterioles in the kidney?
juxtaglomerular cells.
What are juxtaglomerular cells?
specialized cells that act like smooth muscle and contract to limit the amount of blood coming into the capillaries.
what do the juxtaglomerular cells do when they don’t have enough blood flow coming into the afferent arterioles?
release NO
run through the renal autoregulation of GFR for increased map
map increases
GFR increases
juxtaglomerular cells sense this and stop producing NO which vasoconstricts, protecting the kidneys from damage
decreases GFR which brings us back to homeostasis
what are the hormonal and neural regulations that control GFR for increased map?
SNS activation stimulates the release of Epi and Norepi. It also increases renin secretion.
hormonal regulation: epinephrine is hormone that is released
what are carbonic anhydrase inhibitors?
drugs that target NaHCO3 secretion= excess bicarb loss
where do carbonic anhydrase inhibitors work?
primarily in the proximal convoluted tubule
where are receptors for caffeine in the kidney?
in the proximal convoluted tubule
what are adenosine receptors in the kidney?
receptors for sodium. This is what caffeine targets
What is the cycle of carbonic acid being made in the PCT of the nephron?
NHE3. Na+ gets taken back up into the proximal convoluted tubule and H+ is exchanged out.
The sodium gets pumped out by Na+/K+ ATPase pumps.
water follows sodium
H+ binds to bicarb to form carbonic acid by carbonic anhydrase in the urine.
carbonic anhydrase then splits up carbonic acid into CO2 and water.
CO2 diffuses from higher to lower concentration back into the proximal convoluted tubule
inside the proximal convoluted tubule is water. This binds with CO2 via Carbonic anhydrase to form carbonic acid and then it splits again into H+ and HCO3-
We want to keep HCO3- so there’s another transporter that pumps HCO3- out of the cell.
what is carbonic anhydrase?
a enzyme imbedded into the walls of the epithelial cells that puts H+ and HCO3- together to form carbonic acid.
It can also catalyzes the reaction from carbonic acid to water and CO2
what is acetazolamide?
a carbonic anhydrase inhibitor.
As we block carbonic anhydrase we have a build up of bicarb which slows down or stops the sodium hydrogen exchanger. now we have excess sodium and excess bicarb staying in the urine and therefor water follows.
what is the only bicarb wasting diuretic? what is the consequence?
acetazolamide
We can lower the pH of the body below 7.35
