pathophysiology 3rd and 4th powerpoint stuff

as water is reabsorbed _____ rises

Cl-

in the renal tubules what does NH3 form with a proton

NH4+

antiporter membrane proteins

Na+ co-transport with protons

what are the major osmotically active solutes in the plasma and glomerular filtrate

Na+ salts

Na+ and Cl- are transported from the lumen into the cell by a

Na-Cl cotransporter

urea circulation is responsible for concentrating solutes such as

NaCl and Creatinine level in urine

excretion formula

excreted= filtered - reabsorbed + secreted

in osmotic diuresis, increased urine flow results from _________ of osmotically active solute

excretion

is PAH endogenous or exogenous?

exogenous

clearance ratio

clearance of substance divided by GFR (cx/GFR)

reabsoprtion of HCO3- leads to what?

fall in tubular fluid mainly bc of H+ secretion

t/f there is an endogenous substrate that can be used to estimate renal plasma flow

false

t/f the proximal tubule can establish steep gradients for small ions and water

false. distal nephron

if clearance ratio is greater than 1 solute is _____ and it is actively secreted from the _______________ into the tubular fluid

filtered peritubular capillaries

cellular mechanism for proximal tubule H+ and HCO3- transport

filtered HCO3- and secreted H+ from the tubular cell forms H2CO3 wirh help of luminal carbonic anhydrase H2CO3 dissociates to CO2 and H2O

if clearance ratio is less than 1, solute is _______ but ______

filtered but reabsorbed (sodium)

autoregulatory response

filtration fraction increases in order to maintain gfr at constant level

total kidney clearance is dependent on contributions of

glomerular filtration secretion in the proximal tubule reabsorption in distal tubule

a high GFR causes ______ to occur

glycosuria

an increase in splay causes a ______ in glucose threshold

decrease

if absorption of urea/water is stopped in the collecting duct what happens to the osmolarity of the medulla?

decreases and concentration of mechanisms collapse

where are aquaporins found

descending limb of loop of henle distal convulated tubule collecting duct cells

ADH secretion deficiency leads to what disorder?

diabetes insipidus

the _____ nephron has a tight epithelium

distal

5-15% if the filtered K+ reaches the

distal nephron

Which of the following adrenoreceptors are located on the renal vasculature? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a α1-adrenoreceptors b β1-adrenoreceptors

a

second site of sodium chloride and potassium reabsorption is the

ascending loop of henle

Which of the following cells express postjunctional β1-adrenergic receptors? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a Afferent arterial smooth muscle cell b Proximal tubule epithelial cells c juxtaglomerula (JG) cells

b

energy for the natrium reabsorption derives from the __________

basolateral sodium-potassium pump

why does the earliest part of the distal convulated tubule has an osmolality of 100 compared to 285 in plasma?

bc more solute than water is reabsorbed by the loop of henle

why does a reduced tmg lower the threhold?

bc tubules have a diminished capacity to reabsorb glucose

in case of alkalosis, Bicarbonate can do what

be secreted to balance the acid-base homeostasis

distal tubule has active ____ transport via a _______ sensitive Na-Cl-co-transporter

sodium thiazide

aldosterone is responsible for reabsorption of ___ and ____ into the vascular compartment

sodium and water

what does aldosterone regulate?

sodium and water reabsorption and potassium secretion

if clearance ratio >1

solute filtered, actively secreted from peritubular capillaries into tubular fluid (eg potassium)

if clearance ratio < 1

solute filtered, but reabsorbed (eg. sodium)

if clearance ratio = 1.0 ...

solute handled like inulin and renal clearance is = GFR

in the DCT, fluid is _______

hypotonic

urine at the end of TAL is

hypotonic

thick ascending loop of henle is _______ to water and transports _____ into the interstitium of the kidney

impermeable electrolytes

a diuresis is an _______ in urine output

increase

when plasma osmolality is increased plasma avp levels

increase

ADH is released in response to three stimuli

increased blood osmolality decreased blood volume thirst

at low plasma PAH concentrations, the rate of secretion ________ linearly with the plasma

increases

the para-aminohippurate ratio in proximal tubular fluid _______ more steeply than the inulin concentration ratio bc of PAH secretion

increases

aldosterone regulates water absorption by doing what

increasing sodium uptake from the tubular fluid into the blood but potassium is excreted

if clearance ratio is 1 solute is handled like ____ and its renal clearance is equal to

inulin GFR

the _____ form passively penetrates cell membranes with difficulty

ionized

25-35% of the filtered K+ is reabsorbed in

loop of henle

active secretion of urea occurs in

loop of henle

What type of connective tissue is the renal Fascia?

loose connective tissue

water permeability of DCT is _____

low

if ADH is absense the permeability of collecting ducts for water is _____

low, urine will not be concentrated

a reduced tmg _________ the threshold

lowers

30% of the filtered sodium is reabsorbed using a _____________ mechanism

luminal Na-K-2Cl-cotransport

renal clearance units

ml/min

PAH is secreted by what

only proximal tubules

urinary excretion of glucose, glucosuria produces what?

osmotic diuresis

What is amiloride?

potassium sparing diuretic

in renal tubules the secondary phosphate binds a _____ and the result is H2pO4-

proton

renal excretion of ______ is a major factor in

protons

para-aminohippurate (PAH)

provides a measure of function proximal secretory tissue

the ______ tubule has a leaky epithelium

proximal

the tmpah is directly related to the number of functioning _____ tubules

proximal

Where is HCO3- reabsorbed?

proximal convoluted tubule

what nephron segment is responsible for complete reabsorption of glucose and amino acids

proximal tubular fluid

60-70% of the filtered K+ is reabsorbed in the

proximal tubule

reabsoprtion of urea occurs

proximal tubule collecting ducts

volume depletion causes a __________ in cardiac output and renal plasma flow

reduction

what do intercalated cells do?

regulate acid-base homeostasis regulate reabsorption of K+

TAL: prevention of a passive waterflow with watertight junctions leads to a high osmotic pressure in the _________

renal medulla

the clearance of pah =

renal plasma flw

filtration fraction

represents fraction of renal plasma flow that gets filtered by glomerulus

If clearance ratio is ___, then either the solute is too large to be filtered (protein) or it is filtered and 100% reabsorbed

0

normal GFR is approximately ___ mL/min

120

______ % of the filtered sodium is reabsorbed in distal tubule

10

the threshold concentration for glucose greater than 200 mg/dl is

10 mmol/l

ammonium excretion can be ______ increased in case of acidosis

10-fold

at what concentration does kidney start to excrete in individuals with glucose more than 200 mg/dl?

180 mg/dl

_____ of primary urine with electrolytes are reabsorbed

2/3

about ______ % of renal plasma flow becomes gfr

20%

_____% of filtered calcium is reabsorbed in the proximal tubule with paracellular absorption

60%

Normal renal plasma flow is _________ ml/min

600

____% of filtered solutes and water are reabsorbed along PCR

70

phosphate dissociates in the blood to

80% in HPO42-

glucose threshold depends on three factors

GFR TMg amount of splay

in the collecting duct, intercalated cells are responsible for

H+ and HCO2- transport

Acid secreting intercalculated cells have vacuolar what localized to the apical membrane

H+- ATPase and H+-K+-ATPase

in intercalcalated cells cof collecting duct secretion _______ exits the cells in exchange for _______

HCO3- Cl-

aldosterone promotes what hormone secretion

K+

what is the primary function of the collecting duct principal cell

K+ secretion

organic cations can______ H+

RELEASE

Which of the following renal adrenoreceptors activation by the sympathetic nerve directly increases renin secretion? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a β1-adrenoreceptors b α1-adrenoreceptors

a

organic anions can _____ H+ i

accept

aldosterone is produced by

adrenal cortex

K+ reabsorption and excretion is controlled by

aldosterone

how can luminal sodium channels be inhibited?

amiloride

excretion rate

amount of substance excreted into the urine per unit of time

filtered load

amount of substance in plasma that is filtered at glomerulus per unit of time

the descending limb of the loop of henle is water ________ and the ascending limb is water ___________

highly water permeable water impermeable

at high filtered glucose loads the rate of glucose reabsorption reaches a _______ ________ value

constant maximal value

how is NH3 formed in the kidney

deamination of glutamine by the tubular cells and can diffuse into tubular lumen

in the proximal tubule the solvent drag enables paracellular absorption of h2o and cl due to

electrolyte concentrations between tubule lumen and renal interstitium

a low gfr leads to a ______ threshold

elevated

in diabetes mellitus plasma glucose levels are abnormally ________ so more glucose is filtered than can be reabsorbed

elevated

excretion

elimination via urine

if the collecting ducts do not have ADH what happens?

fluid leaving distal tubules remains hypotonic distal tubules cortical and outer medullary collecting ducts are impermeable to water medullar collecting duct reabsorbs nacl and is permeable to water/urea large amounts of hypotonic urine flow into renal pelvis daily

TAL of henle transporting electrolytes into interstitium of kidney produces a ___________ of the interstitium

high osmotic pressure interstitium

s1 segment of the proximal tubule is characterized by

high-flux low affinity glucose transport

fluid from PCT is ______ to plasma

isomotic

tubular fluid entering the loop of henle is ______ to plasma, but fluid leaving the loop is _______

isotonic hypoosmotic

the tmpah provides a measure of the _____ ______ ______ secretory tissue

mass of proximal

symporter membrane protein

na co transport with glucose, galactose, phosphate, sulfate, or amino acids

Furosemide inhibits Na-k-2cl cotrasnporter and leads to a massive _______ and loss of _______

natriuresis potassium, calcium, magnesium

H2PO4- can is be reabsorbed?

no

can NH4+ be reasbsorbed?

no

when cl moves out of the late PCT what does the potential created favor

passive na reabsorption

in the DCT, when AVP is present the cortical collecting ducts become water ______ and water is passively reabsorbed into cortical interstitial fluid

permeable, High blood flow in cortex carries this water away so cant detect lowering of cortical tissue osmolarity

mechanisms of acid-base homeostasis

phosphate excretion reabsorption of bicarbonate ammonia excretion

the s3 segment is characterized by

reverse low flux high affinity glucose transport system

what is splay?

rounding of the glucose reabsorption curve

at high plasma PAH concentrations the secretory carriers are ______

saturated

at tmgo the tubule glucose carriers are all ______ and trasnport glucose at _______ rate

saturated maximal

in case of too high glucose this mechanism is subject to

saturation and glycosuria results

on the luminal side of the proximal tubule epithelium sodium enters the cell via

symporter membrane protein antiporter membrane protein

renal clearance

the volume of plasma thats completely cleared each minute of any substance that finds its way into urine

_____ inhibit sodium reabsorption is distal tubule and lead to a mild ______ w/o loss of calcium

thiazides diuresis

t/f changes in kidney function will change plasma concentrations of drugs

true

t/f if the non-ionized form is lipid soluble it can diffuse thru the lipid bilauer of cell membranes down conc gradients

true

in the proximal tubule, when water is reabsorbed and cl rises, what type of concentration gradient is created

tubular fluid to plasma concentration gradient that favors cl- diffusion out of tubule lumen

what causes splay?

tubular heterogeneity

why does the tubular glucose reabsorption not abruptly attain tmg when plasma glucose is elevated

tubular heterogeneity glucose carrier does not have an infinitely high affinity

the constant maximal value that high flitered glucose reaches is called

tubular transport minimum for glucose