Renal Day 2 Flashcards
what are macula densa cells?
cells that detect content of tubular fluid to know what to pass through (on distal convoluted tubule that sits next to afferent arteriole)
what are mesangial cells?
border glomerulus and function as precapillary sphinters to control pressure through glomerulus
what is the tubular pole?
where proxima convoluted tubule emerges off bowman’s capusel
what are podocytes?
filtration slits that sit outside the fenestrated glomerulus
what type of cells makes up the tubules of a nephron?
simple cuboidal with microvilli
what type of cells make up the loop of Henle?
simple squamous
what is normal plasma osmolarity?
300
where does most of reabsorption occur?
proximal convoluted tubule
what happens to tubular fluid osmolality as it passes through the loop of Henle?
- descending osmolality increases
- ascending osmolality decreases and becomes hypoosmotic
- collecting duct urine is dilute and has low osmolality
what is the normal urine output per day?
1-2L
which leg of the loop of Henle is immpermeable to water?
ascending limb
which leg of the loop of Henle is not permeable to solutes?
descending loop
where are principle cells located?
distal convoluted tubule and collecting duct
-use aldosterone and ADH to reabsorb more water
what are intercalated cells?
they control and monitor pH by secretion of hydrogen and potassium into the tubular fluid
located at distal end of DCT
where are the two places that contain transitional epithelum?
ureters
bladder
what is the triangular area in the bladder?
trigone
ureteral openings and neck of urinary bladder
is there a true sphincter in the bladder?
no (contains a physiologic valve)
-ureteral reflux
how many layers does the detrusor muscle have?
3 layers of smooth muscle (not skeletal)
what is a risk factor for bladder infection?
stasis (urine staying in the bladder)
age causes weakening of muscles
what is an intravenous pyelogram?
way to visualize the urinary system
what is the rate of secretion?
(glomerular filtration + tubular secretion) - tubular reabsorption
how much filtrate is produced each day?
150L f
180L m
what is the net filtration pressure at the glomerulus?
10mmHg
what is the hydrostatic pressure at the glomerulus?
55mmHg
what is the relationship between mesangial cells and filtration rate?
relaxed cell = higher rate
contracted cell = lower rate
what is the definition of GFR?
amt of filtrate formed in all the nephrons in both kidneys each minute
what happens when GFR is too high?
reabsorbed materials aren’t sufficient
what happens when GFR is too low?
reabsorbed materials will include some waste
when will filtration halt?
when hydrostatic pressure drops below 45mmHg
-when not enough perfusion is coming in
what is the lower and upper threshold of MAP at which GFR would change?
80-180mmHg
what are the 4 ways in which the kidney autoregulates?
- myogenic (works w/in seconds)
- tubuloglomerular feedback
- neural feedback
- hormonal feedback
if systemic blood pressure is higher, what happens in the kidney?
flow of fluid in the tubular system is faster
macula densa inhibits NO which vasoconstricts afferent arteriole
how does sympathetic input impact glomerular?
GFR is decreased b/c afferent constricts more than the efferent
-shunting of blood , shock b/c of hemorrhage, dehydration or stress
when does the body make atrial natriuretic peptide?
hypervolemia
-diuresis the body
what is paracellular reabsorption?
solutes move across to capillary in between cells
what is transcellular reabsorption?
solutes move across to capillary going through the tubular epithelial cells
what is a transport maximum?
depends on number of protein transporters and how fast they work
-glucose threshold as example
what is a aquaporin 2?
pure water channel (ADH related)
