Unit 8 - 1 Physio

Front 1

where are glomeruli located

Back 1

cortex

Front 2

glomerular capillaries (no protein gets cross)

Back 2

permeability of glomerulur capillary greater than permeability of muscle capillary for small molecular compounds, but smaller for proteins (more protein across muscle capillary than glomerular capillary)

Front 3

post-renal problems (kidney stones)

Back 3

Pt goes up

Q = Kf [(Pc - Pt) - (Pip - Pit)]

Front 4

permeability of muscle cap to kidney cap

Back 4

negative charge interacts w podocytes; they fuse/go away when you start spilling protein; dissappearance of podocyte = onset of micro albuminemia

Front 5

where does protein trapped supepithelially go back through basement membrane back into capillary?

Back 5

charge on all three layers are negative; proteins pushed back by negative charge

Front 6

glucose is freely filtered

Back 6

100 ml of water filtered = 100 ml of glucose filtered

filter out 100 ml, across filtration barrier into bowmans space;

point: glucose free to filter, protein is not

Front 7

renal cap vs muscle cap

Back 7

hydrostatic stays same, oncotic pressure increases in renal capillary

in muscle hydrostatic decreases towards venous side, oncotic decrease

Front 8

explain how tone of afferent/efferent arteriole can be altered to change plasma hydrostatic pressure

Back 8

you can constrict one or the other independently to regulate pressure

Front 9

filtration/equilibrium

Back 9

offsetting pressures are equal to eachother from that point on to the end of the capillary

Front 10

diabetes insipidous

Back 10

no ADH

Front 11

compare conc of glucose in the afferent and efferent arterioles

Back 11

they're equal; when you move water you move glucose bc it's FREELY FILTERED unlike protein

Front 12

factors which affect ability of molecules to move across the glomerular cpiallary

Back 12

creatinine, urea, glucose

same conc in urine as in plasma bc they're all freely filtered

Front 13

purpose of podocyte

Back 13

support to capillary basement membrane (bc theres on muscle in renal capillaries); inbetween interlocking parts is a filtration slit which is where filtration is thought to take place

Front 14

Back 14

polyanionic = negative = not filtered well
neutral = bettter
polycatoinic = positive = filtered best

Front 15

Donnan effect

Back 15

proteins are held back in capillary fluid (negative charged); hold back positively charged ocmpounds like sodium or potassium

negatively charged compounds get pushed across faster

Front 16

how can you increase GFR and decrease renal blood flow

Back 16

constrict efferents flow goes down, pressure goes up bc the flow is not getting up, GFR goes up, renal blood flow go down

Front 17

how can insulin be used to calculate the GFR

Back 17

C = UV/P

you can only do this with inulin bc it is freely filtered and is neither reabsorbed nor secreted

Front 18

characteristics a compound must have before it can be used to calculate GFR

Back 18

cant be toxic, must be measurable, cant alter GFR, freely filtered, must be secreted or reabsorbed

Front 19

rhabdomyolysis

Back 19

breakdown of muscle; can be toxic to kidney

Front 20

Pin x GFR = Uin x V

Back 20

Urine volume x Concentration = amount excreted

Qf = Qe

Front 21

where is filtrate generated?

Back 21

glomerulus

Front 22

where does distal tubule pass next to?

Back 22

glomerulus

Front 23

what can the kidney synthesis

Back 23

bicarb, some hormones

otherwise only puts stuff INTO the blood or takes it OUT of the blood

Front 24

How is renal tubular fluid obtained?

Back 24

filtration (at glomerulus) and secretion

Front 25

How much work do kidneys do?

Back 25

Huge amount (180L water); most material comes from blood and most goes back to blood

its a way to eliminate things from blood that we dont need

Front 26

why do we not need to consume this volume of filtered material

Back 26

most material filtered by kidney is reabsorbed (similar to gut; material from blood into tubule, which makes it outside body)

Front 27

Back 27

Filtration generates fluid -> (all small components from blood, no rbc or large proteins)


We absorb water by absorbing all the ions which drives the fluid through back into blood after filtration

Front 28

Back 28

note collecting duct is impermeable to water without ADH initiation of aquaporin transport to membrane

Front 29

which segment reabsorbs the most sodium

Back 29

most in prox tubule

Front 30

which segment absorbs sodium to adjust renal interstitial fluid concentrations?

Back 30

loop of henle

Front 31

which segment is associated with regulation of sodium for body?

Back 31

3% in CD; this is where sodium in blood is mostly regulated; all the other absorbtion sites are necessary

Front 32

Back 32

note AA, glucose at the end of the prox tubule are virtually zero; it means they are completely reabsorbed as the fluid moves along the proximal tubule

note the Na and Cl conc dont change much bc they draw water with them whenever theyre reabsorbed

bicarb gradually reabsorbed (major buffer system in body)

urea and creatinine as they move along their concentration begins to rise which indicates that they're not being reabsorbed

Front 33

Na and H absorbtion in first half of prox tubule

Back 33

Absorb sodium, secrete hydrogen which binds to bicarb (which generates C02 and water) -> this is how bicarb is reabsorbed bc bicarb is not permeable but C02 and water are permeable -> C02 diffuses out into the body to be reconverted into the body or secreted through lungs

this leaves Na, Cl, K, and water in the second half of prox tubule

Front 34

Back 34

Secondray active transport: Glucose down conc. gradient by facilitated diffusion, Na exchanged by Na/K pum, same w/ amino acids (same as GI)

Note sodium, hydrogen exchange, combines with bicarb for C02, C02 reabsorbed

note sodium bicarb exchanger (secondary active)

Front 35

Back 35

Hydrogen ions going out, anion comes back in; electrically neutral process so doesnt disturb Na or cl reabsorption

These are mechanisms by which rebaosprtion processes are going on; specific transporters;

Front 36

why is glucose not normally present in urine?

Back 36

at normal blood glucose levels (blue line = transport); amount in filtered load is totally reabsorbed under normal conditions

Front 37

What is the glucose excretion for this patient? (GFR = 90, plasma glucose = 2 mg/ml, Tm = 150)

Back 37

Filteredglu = GFR x Pglu = 90 x 2 = 180 mg/min
Reabsglu = Tmax = 150 mg/min
Excretglu = 30 mg/min

Front 38

What stuff is secreted in the proximal tubule?

Back 38

Endogenous anions, cations, drugs; once this stuff is in the renal filtrate it ends up in the urine

Front 39

anions

Back 39

Yes you have to know what OAT1,3,4 do; they can be targets of drugs causing excretion or reabsorbtion

cations

Front 40

distal convoluted tubule: continues the dilution started by the ascending limb

Back 40

at the top of loop of henle you have the highest conc of fluid in the body; as it moves up it loses ions (diluting fluid) as it enteres DCT; as it contines sodium and Cl reabsorbed back into body but water is NOT rebaosbred (these cells dont have aquapores); this dilutes fluid

Front 41

Sodium chloride transport in early distal tubule

Back 41

Site for thiazide diuretics; if you block the reabsorbtion of sodium and chloride you have a large ionic content in tubule which traps water in the tubule which is excreted in collecting duct

Front 42

what does aldosterone do?

reabsorption of sodium (not really regulation bc the sodium came from blood and puts it back into blood)

Back 42

Potassium into tubular lumen, sodium reabsorbed, potassium taken out of interstitial fluid

SECRETION of K in exchanged for Na and Cl;
Na/K pump sensitive to aldosterone which moves greater amounts of sodium into blood which leads to increased potassium excretion

Front 43

Macula densa

Back 43

located on distal tubule; J/G cells along afferent and efferent arterioles

constrict afferent (filter less)
constrict efferent (filter more bc increased pressures)
can adjust both proportionally where nothing changes

Front 44

Back 44

cells in macula densa sensitive to how much sodium is being reabsorbed; too much sodium in tubular fluid leads to too much sodium being reabsorbed which signals to cells to release adenosine and ATP detected by granular and vascular smooth muscle cells on afferent arteriole; will active CaC which will raise levels in smooth muscles = vasoconstriction

Front 45

Note ATP will release NO in cell but in the macula densa ATP causes vasoconstriction when is acts ON muscle receptors

Back 45

Front 46

Back 46

be familiar with this slide