Physiology Test 3

Front 1

what are the four functions of the kidney?

Back 1

regulate plasma volume, water balance, arterial pressure, and electorlyte composition

acid-balance balance

excretion of waste products (creatinine, urea, drugs, toxins)

hormone secretion

Front 2

the total body water percentage in adult males is __, adult females is __, and infants is __

Back 2

55-60%, 50-55%(increased fat content), 65-75% (high soft tissue content)

Front 3

__ has the highest percentage of water

Back 3

muscle

Front 4

the total body water average is __%

Back 4

60

Front 5

in a 70 kg person, if there is a 60% TBW, how many liters of water are in there body?

Back 5

42

Front 6

how do you find TBW?

Back 6

%of water body weight x body weight

Front 7

what is the distribution of water in various body compartments?

Back 7

40% intracellular fluid; 20% extracellular fluid (15% interstitial fluid, 5% plasma)

60:40:20:5 rule

Front 8

how do you find blood volume as a measure of hematocrit?

Back 8

BV=Plasma volume/1-Hct

Front 9

what is the equation of blood volume?

Back 9

blood volume=plasma volume+hematocrit

plasma volume=5% total body weight

Front 10

what is the distribution ratio of water between the ECF and ICF?

Back 10

40:20

Front 11

what factor determine the distribution (40:20) of water between ECF ICF

Back 11

osmotic gradients

Front 12

what is osmotic pressure?

Back 12

the pressure of a solution created by proteins that equals the minimum hydrostatic pressure required to stop the net influx of water across a semipermiable membrane

Front 13

when the osmolarity of two solutions are equal

Back 13

iso-osmotic

Front 14

when a solution has a lower osmolarity than the solution to which it is being compared

Back 14

hypo-osmotic

Front 15

when a solution ahs a higher osmolarity than the solution to which it is being copmared

Back 15

hyperosmotic

Front 16

explain what happens to a cell when its emerged in a iso-osmotic, hypo-osmotic, and hyperosmotic solution

Back 16

iso-doesn't change

hypo-cell swells

hyper-cell shrinks

Front 17

explain osmolarity

Back 17

it is the sum of the molarities of osmotically active particles in solution

Front 18

what is the osmolar concentration and electrochemical equivalence of a protein molecule like albumin?

Back 18

albumin has 18 negative charges

one mole of albumin equals 18 eqivalents of ablumin

one mole of albumin is one 1 OsM

Front 19

within each compartment, __ = __

Back 19

total positive=total negative

Front 20

what is the concentratoin of Na and K in ECF and ICF

Back 20

ECF: Na 135-145 mEq/L, 3.5-5 mEq/L

ICF: Na 10-20 mEq/L, K 130-140 mEq/L

Front 21

what four things make ionic copmositions of ECF and ICF so different?

Back 21

semi-permeable cell membrane

inside negative membrane potential

Na-K-ATPase

intracellular localization of multivalent proteins

Front 22

what are the osmotic composotions of the major fluid compartments?

Back 22

toatl osmotic concentrations of extracellular and intracelluluar fluids are similar despite having different total ionic concentrations

BECAUSE THERE IS AN EQUAL NUMBER OF PARTICLES IN EACH COMPARTMENT

Front 23

what two factors determine volume and distribution of water between various compartments

Back 23

osmotic gradient, proportion of relative volumes of compartments

Front 24

what two questions need to be asked about evetns that follow an osmotic distrubance in teh body?

Back 24

becuase all exchanges happen through the ECF,

does the distrubance cause a change in ECF osmolarity and does the water need to shift into our out of cells to attain osmotic equilibrium?

Front 25

explain the fluid movment in diarrhea

Back 25

because you loose equal amounts of water and ions the fluid lost is osmotic. therefore there is no shift in water between ICF and ECF

isoosmotic volume contraction

Front 26

what happens with water deprivation in a desert?

Back 26

mainly water is lost so the concentration in teh ECF increases, water shifts from ICF to ECF to maintain equillibrium

hyperosmotic volume contraction

Front 27

how does fluid shift in a high NaCl intake situation?

Back 27

ECF osmolarity increases

water shifts from ICF to ECF

ICF volume is decreased

hyperosmotic volume expansion

Front 28

what is the effect of drinking a lot of water?

Back 28

water moves freely between compartments (in 40:20 ratio)

ICF volume expansion, decreased osmolarity

ECF volume expansion, decreased osmolarity

Front 29

what is the effect of low salt diet or Na deficit on teh volume and osmolarity of ICF and ECF?

Back 29

decreased osmolarity of teh ECF, movment of water from ECF to ICF, decreaesed blood pressure

Front 30

what are the four major regions of the kidney?

Back 30

outer region: cortex (granular appearance b/c of small tubules and globulus)

medulla: tubules much bigger in size (collecting ducts) has a striated appearance

pelvis: where filtered urine is collected

Front 31

what are the papilla?

Back 31

where tubules merge

Front 32

where the tubes to the pelvis lie

Back 32

calyces

Front 33

connects the kidney to the bladder

Back 33

ureter

Front 34

teh fibrous covering of the kidney to keep it away from teh external enviornment

Back 34

capsule

Front 35

there are __ nephrons in each kidney

Back 35

1 million

Front 36

each nephron joins a __ to the __

Back 36

collecting duct, papilla

Front 37

the functional unit of the kidney is the __

Back 37

nephron

Front 38

what are characterisitcs of superficial nephrons?

Back 38

glomulus is near the outside region of the cortex with loops that go down into the outer medulla

Front 39

what are the characteristics of juxtamedullary nephrons

Back 39

the glomerulus is closer to the medulla with loops down close to papillary region

Front 40

__% of nephrons in teh kindey are superficial nepherons

Back 40

85

Front 41

what is teh renal corpouscle composed of?

Back 41

glomular capillaries and teh bowmans capsule

Front 42

trace the path of the nephron

Back 42

afferent arteriole--glomerular capillary--proximal convoluted tubule--proximal straight tubule--thin descending limb--thin ascending limb--thick ascending limb--distal convoluted tubule--collecting duct (prinipal and intercalated cells)

Front 43

describe the layers of the nephron cell from the intersitial side to the lumenal side

Back 43

ISF--basoalteral membrane--apical side (microvilli for reasorbtion [increases SA] --lumen

Front 44

capillaries are on teh __ of the nephron

Back 44

basolateral

Front 45

what are the three kinds of capillary beds around the nephron

Back 45

glomerular, peritubular capillaries, vasa recta

Front 46

the __ capilalries wind around teh nephron

Back 46

peritubular

Front 47

the efferent arterioles of teh juxtamedullary nephron branches into __ (90%) and __ (10%)

Back 47

peritubular; vasa recta

Front 48

the vasa recta enters teh __ and surrounds the __ to concentrate the urine by a complex mechanism of counter current exchange

Back 48

medulla, loop of henle

Front 49

the vasa recta return blood to __ which lead to the __ and back into the system circulation

Back 49

interlobular veins, renal veins

Front 50

what is teh macula densa and what does it do?

Back 50

cells inbetween the afferent and efferent arterioles that sense what is going on in the tubule control vasoconstrction/vasodilation to regulate the flow of ions

Front 51

what do granular cells secrete?

Back 51

renin

Front 52

how does the brain control blood flow in the kidney?

Back 52

the sympathetic nervous system

Front 53

__ ml of plasma comes through teh glomerular capillaries but only __ ml gets filtered

Back 53

600, 125 (1/5)

Front 54

reabsorption occurs in the __

Back 54

nephron

Front 55

secrtion occurs from teh __ to teh __

Back 55

peritubular capillaries, nephron

Front 56

what is the equation for excretion?

Back 56

E=filtered-reabsorbed+secreted

Front 57

the formation of virtually protein-free filtrate of plasma as blood passes through the glomerular capillaries

Back 57

ultrafiltration

Front 58

as teh size of the molecules being filtered increases, its ability to be filtered __

Back 58

decreases

Front 59

what are the three kinds of filters blood passes through in the kidney?

Back 59

size, charge, and shape

Front 60

explain teh glomular membrane and how it functions as a filter

Back 60

made up of three sieves in series

capillary endothelium, basement membrane, and podocytes

Front 61

explain the size barrier for the glomular membrane

Back 61

endothelial membrane has fishnet holes in it called fenestrations. they are large holes that let filtrate through

the basement membrane has a thick, mazelike structure

the space between pedicles are the filtration slits. these are teh fineset barriers

Front 62

describe how the glomerular membrane has shape (steric) filtration

Back 62

the basal lamina only allows slender molecules to go through

Front 63

explain how the glomerular membrane has an electrostatic restriction filter

Back 63

glycolax are proteins along teh cells of teh basement membrane that have a very electronegative environment. they repel negatively charged protein molecules like albumin

Front 64

what is teh most important component to filtration?

Back 64

charge

Front 65

the total length of the glomerular capilllaries is ~ __

Back 65

12 miles

Front 66

why is there a steep decrease in pressure at the afferent and efferent arterioles but not in the glomerular capillaries?

Back 66

the capilaries are set up in series which decreases resistance, stabilizing pressure

Front 67

explain the starling forces that affect the glomerular capillaries

Back 67

Glomerular capillary hydrostatic pressure (45-50 mmHg) Pgc (DRIVING FORCE FOR FILTATION)

Bowmans space colloid osmotic pressure (0 mmHg) pibs PRESSURE FROM PROTEINS IN THE FILTRATE

Bowmans space hydrostatic pressure (10-15 mmHg) Pbs PRESSURE OF FILTRATE PUSHING BACK ON TEH CAPILLARY

Glomerular capillary colloid osmotic pressure (25 mmHg) pigc PROTEINS IN THE BLOOD PULLING FILTRATE BACK IN

Front 68

what is the equation for net filtration pressure?

Back 68

Net filtration pressure=(Pgc-Pbs)-(pigc-pibs)

Front 69

the net filtration pressure favoring filtration in glomular capillaries should be __

Back 69

10 mmHg

Front 70

explain why filtration slows as blood flows from teh afferent to the efferent arteriole

Back 70

as more things are filtered out of the blood, the colloid pressure increases as proteins become more concentrated, decreasing filtration

Front 71

what is the equation for the glomular filtration rate?

Back 71

GFR=Kf x net filtration rate

Front 72

what is Kf

Back 72

the water permeability of teh glomerular capillary

Front 73

what two things contribute to the high Kf in teh glomeruli?

Back 73

surface area and hydaulic conductivity

Front 74

explain the forces aiding in reabsorption in teh peritubular capillaries

Back 74

pressure int eh glomerular capillary decreases and teh colloid pressure in teh blood increases creating a suction force

Front 75

the renal fraction of cardiac output is about __%

Back 75

20

Front 76

__% of renal blood flow goes to the cortex, __% goes to teh outer medulla and __% goes to the paillae

Back 76

90, 8, 2

Front 77

what is the equation for renal blood flow

Back 77

flow=arterial pressure-venous pressure/resistance, deltap/Rt

Front 78

what is the normal amount of blood flow in a normal 70 kg person?

Back 78

1200 ml

Front 79

describe the pressure from teh renal artery to the efferent arteriole

Back 79

renal artery (100 mmHg)--resistance increases in teh arterioles which decreases pressure--pressure is stable in teh glomular capillary due to parralel arrangment

Front 80

how do you calculate toate renal vascular resistance (in order to calculate renal blood flow)

Back 80

Rt=Ra+Re

Rt=total renal vascular resistnace

Ra=afferent arteriolar resistance

Re=efferent arteriolar resisatnce

Front 81

how is the physiological regulation of GFR generally achieved?

Back 81

changes in Pgc

Front 82

Pgc is directly proportioal to __ and inversely proportional to the __

Back 82

resisatnce in the efferent arteriole, resistance in the afferent arteriole

Front 83

constriction of teh afferent arteriole __ resistance and __ RBF, Pgc, and GFR

Back 83

increases, decreases

Front 84

constriction of teh efferent arteriole __ resistance, Pgc, and GFR but __ RBF

Back 84

increases, decreases (RBF=deltaP/Rt, Pgc=Re/Ra)

Front 85

a decrease in afferent resistance = __

Back 85

increase in RBF, increase in GFR

Front 86

an increase in afferent resistance =

Back 86

decreased RBF, decreased GFR

Front 87

decreased efferent resistance causes __ RBF and __ GFR

Back 87

increased, decreased

Front 88

increased efferent resistance causes __ RBF, __ GFR

Back 88

decreases, increases

Front 89

explain autoregulation of the kidneys arteriole

Back 89

the kidney maintians a fairly constant flow rate at changing pressures by regulating afferent and efferent arteriole pressure

Front 90

explain the mechanisms of autoregulation

Back 90

intrisic: myogenic (compliance), tubuloglomerular feedback mechanism

extrinsic: sympathetic nervous system, renin-angiotensin system, vasodilators

MAINLY INTRINSIC

Front 91

explain teh interinsic myogenic autoregulation mechanism

Back 91

increased BP--stretch of the arteriole wall--vascular contraction--decreased renal blood flow

Front 92

how much of autoregulation does the myogenic mechanism account for?

Back 92

50%

Front 93

explain the tubuloglomerular feedback mechanism

Back 93

increased GFR--increased flow through teh tubule--increased flow past the macula densa--paracrine signal from the macula densa to the afferent arteriole (adenosine)--afferent arteriole constricts--increased resistance in afferent arteriole--decreased Pgc

opposite occurs with decreased GFR

Front 94

sympathetic innervation of renal microvasculature affects __ arterioles more than __

Back 94

afferent, efferent

Front 95

sympathetic has __ influence on BASAL renal vascular resistance

Back 95

little to no

Front 96

explain how the influence of the sympathetic nervous system activation acts on renal hemodynamics?

Back 96

increased BP--increased RBF--increased SNS--NE release from teh nerve terminals--increased afferent arteriole resistnace--decreased RBF and GFR

Front 97

angiotensin II __ the afferent arteriole and __ the efferent arteriole

Back 97

constrict or no effect, constrict

Front 98

atrial natriuetic peptide (ANP) __ the afferent arteriole and __ the efferent arteriole

Back 98

dilate, constrict or no effect

Front 99

vasopressin __ the afferent arteriole and __ the efferent arteriole

Back 99

constrict or no effect, constrict

Front 100

NO __ the afferent arteriole and __ the efferent arteriole

Back 100

dilate, dilate

Front 101

how does angiotensin II regulate kidney function?

Back 101

low BP--low RBF--low salt at MD--renin release--angiotensin II--arteriolar AT1 receptors--increased efferent arteriole resistant, increased affarent arteriole resistnace, decreased Kf--decreased RBF and maintained GFR--salt and water retention increases BP

Front 102

most vasodilators __ GFR and RBF plateau levels while most vasoconstrictors __ GFR and RBF plateau levels

Back 102

increases, decreases

Front 103

the volume of blood flowing through the kidney

Back 103

renal blood flow

Front 104

what is the equation of renal blood flow (in terms of hmct)

Back 104

RBF=RPF/1-Hct

Front 105

the volume of plasma flowing through the kidney

Back 105

renal plasma flow

Front 106

what is the equation for renal plasma flow?

Back 106

RPF=RBF x (1-Hct)

Front 107

what is the daily glomular filtration rate?

Back 107

180 L/day

Front 108

the fraction of plasma filtered at teh glomeruli

Back 108

filtration fraction

Front 109

what is the equation for filtration fraction?

Back 109

GFR/RPF; 125/605; 20%

Front 110

the percentage of teh sodium filtered by teh kidney which is excreted int eh urine

Back 110

fractional excretion of sodium

Front 111

what is the equation for teh fractional excreiton of sodium?

Back 111

FEna=CNa/GFR

Front 112

__ is an example of a substance that is completely filtered and excreted, __ is an example of a susbstance that is filtered and partially reabsored and excreted, __ is an example of a substance that is filtered and completely reabsorbed and __ is an example of a substance that is filtered, secreted, and excreted

Back 112

inulin, Na, glucose, creatinine

Front 113

why is jeruselum artichoke important to renal physiology?

Back 113

it contains inulin which is used as a marker for GFR because it is not reabsorbed by the intestines

Front 114

how can you find GFR based on inulin?

Back 114

Pin x GFR = Uin x V

Pin=levels of ingested inulin

Uin=levels of urinary inluin

V=urinary flow

Front 115

why does renal plasma clearance of inulin equal GFR?

Back 115

because all of the inulin that is consumed is filtered and excreted (no reabsorption or secretion)

Front 116

what does it mean if the renal clearance of a substance is less than the renal clearance of inulin (Cx<Cn)

Back 116

net reabroption of x, x not freely filtered, x is metabolized by the kidney

Front 117

what does it mean if the reanl clearance of a substance is greater than that of inulin? (Cx>Cin)

Back 117

net secretion of X or X is synthesize by teh kidney and secreted

Front 118

why is the renal clearance of glucose 0?

Back 118

b/c it is all filtered then all reabsorbed back

Front 119

why is the renal clearance of creatinine higher than that of inulin?

Back 119

it is filtered but also secreted from the kidney as well

Front 120

what is the equation for calculating GFR with creatinine?

Back 120

Ccr (GFR)=Ucr x V/Pcr

(less invasive than inulin)

Front 121

how can you use creatinine to show kidney dysfunction?

Back 121

if there is harm to the kidney, filtration goes down, plasma concentration of creatinine goes up

Front 122

explain how the kidney handles PAH

Back 122

90% is removed from plasma in a single passage through teh kindey

10% is not available for secretion b/c it passes through teh vasa recta

Front 123

Cpah is a measure of plasma flow through parts of teh kidney that are effective in removing PAH from plasma also known as __

Back 123

ERPF; Cpah=Upah x V/Ppah

Front 124

how do you convert effective renal plasma flow to actual renal plasma flow?

Back 124

multiply by .9 (90% goes through kidney, 10% is returned to circulation

Front 125

what are the basic mechanims of transepithelial transport in the renal tubule?

Back 125

active transport, antiport, symport, facilitated diffusion, diffusion through membrane channels, endocytosis

Front 126

what are the 4 examples of primary active transport in the tubules?

Back 126

Na-K atpase

H+ atpase

H-K atpase

ca atpase

Front 127

what is the main driving force of the gradient for secondary active transport in the tubules?

Back 127

Na-K atpase

Front 128

where is Na-K atpase located in the tubules

Back 128

basolateral membrane

Front 129

what are examples of symport and antiport exchangers in the tubules?

Back 129

symport: Na-glucose symporter

antiport: Na+-H+ antiporter

Front 130

__% of glucose is absorbed in the proximal tubule

Back 130

>99

Front 131

glucose is reabsorbed into the proximal tubule via the __. glucose is then transported to the intersitial fluid via the __

Back 131

glucose-Na+ symporter; GLUT2 facilitated transporter (Na is taken out by the Na-K pump)

Front 132

the equation for glucose filtration rate is __

Back 132

Pg x GFR

Front 133

the equation for glucose secretion rate is __

Back 133

Ug x V=0 (none secreted

Front 134

glucose reabsorbtion rate=__

Back 134

glucose filtration rate

Front 135

explain the threshold for glucose in the kidney

Back 135

the minimum plasma glucose at chich glucose will appear in the urine (200 mg/dl)

Front 136

explain the transport maximum for glucose

Back 136

the point at which increases in concentration do not result in an increase in movement of a substance across a membrane

Front 137

how much Na is normally filtered by the kidney's each day?

Back 137

2 containers of salt worth

Front 138

__% of Na is reabsorbed in the proximal tubule

Back 138

67 (33% remaining)

Front 139

__% of Na is reabsorbed in the thick ascending limb

Back 139

25% (8% remaining)

Front 140

__% of Na is reabsorbed in the distal convoluted tubule

Back 140

5% (3% remaining)

Front 141

__% of Na is reabsorbed in teh distal collecting tubule

Back 141

<3% (this is where the bulk of regulation occurs)

Front 142

__ is the hormone that regulates Na reabsorbtion

Back 142

aldosterone

Front 143

explain teh mechanisms in which Na is reabsorbed in the proximal tubule

Back 143

NHC3 transporter brings in Na, amino acids, and glucoes

Na, H antiporter brings in Na and takes out H+

Na-K pump takes Na back to peritubular capillaries

Front 144

explain how Na reabsorbtion occurs in teh thick ascending limb

Back 144

MAJORITY: NKCC2 transporter brings in Na, K, and 2 Cl-

Na-H+ antiporter

Na-K pump takes Na back out

Front 145

explain how Na reabsorption occurs in teh distal convoluted tubule

Back 145

NaCl transporter brings Na in

Na-K pump takes Na out

Front 146

explain how Na reabsorbtion occurs in the collecting tubule and principal cells of teh collecting ducts

Back 146

ENAC (epithelial sodium channel) brings Na in

Na-K pump takes it out

Front 147

loop diueretics block the __ channel.

Back 147

NKCC2, Na keeps going through teh tubule, water follows Na molecules out into the urine

Front 148

thiazides block __

Back 148

NCC

Front 149

amiloride block teh

Back 149

ENaC channels

Front 150

what is the concentrating limb?

Back 150

the portion of teh discending limb of teh neuron where water is reabsorbed

Front 151

what is the diluting limb?

Back 151

the portion of tehthik ascending limb that is highly impereable to water but highly permable to Na

Front 152

how does ADH act on the collecting ducts?

Back 152

it places aquaporin channels on them to concentrate the urine

Front 153

what are teh requirements for H20 reabsorption accross the trubular epithelium?

Back 153

driving force across teh epithelium

water permeable epithelium

Front 154

what causes a water permeable epithelium?

Back 154

junctional complexes connecting neighboring cells may be "leaky" allowing H20 to pass through

aquaporin channels

Front 155

desbribe the coupling of Na to H20 in teh nephron

Back 155

in some nephron segments, H20 reabsorptin is tightly coupled to solute reabsorption

in some nephron segments, H20 and solute reabsorption are dissociated

Front 156

water reabsorption happens mainly in the __ and __ because the osmolarity of Na increases as you go deeper in teh nephron.

Back 156

descending limb, collecting ducts.

these have a lot of aquaporin in them

Front 157

describe isotonic water reabsoption in teh proximal tubule

Back 157

as ultrafiltrate is reabsorbed into the interstitium, the osmolarity increases slightly enough to transport water along with it

Front 158

why is there water reabsorbtion in the descending thin limb without Na reabsorbtion?

Back 158

relatively high hydraulic conductivity of aquaporin

osmotic gradient is established by transport activity of other cells

Front 159

the __, __, and __ are all H20 imperable

Back 159

asceding thin limb, thick ascending limb, distal convoluted tubule

Front 160

water and Na are only coupled in teh __

Back 160

proximal tubule

Front 161

explain how water can be reabsorbed in the collecting duct during extreme conditions

Back 161

adh is produced by the pituitary gland which binds to V2R receptors stiumlating cAMP which causes AQP2 aquaporins to be released onto the apical membrane. water moves into the cell and out into the bloodstream via aquaporins on the basolateral side.

Front 162

explain teh effect of poorly reabsorbale solutes like glucose on H20 reabsorbtion

Back 162

b/c glucose is only reabsorbed in the proximal tubule, after it travs through the tubule to the collecting duct where water follows it into the urine. this is called diuresis

Front 163

sodium input must equal __

Back 163

sodium output

Front 164

what contributes to sodium input and output?

Back 164

input: diet (155 mmol/day)

output: sweat (2.5 mmol/day), feces: 2.5 mmol/day, urine 150 mmol/day

Front 165

sodium is __ secreted

Back 165

NEVER

Front 166

explain what causes the production of angiotensin II and aldosterone?

Back 166

low ECF volume and or low blood pressure stimulate renin release. renin convertes angiotensinogen into Ang I. Ang I is converted to Ang II by ACE.

Front 167

explain the regulation of renin secretion

Back 167

decreased blood pressure--stimulation of carotid and aortic baroreceptor--cardiovascular control center--increased sympathetic activity--stimulates beta receptors on granular cells--increased renin

decreased blood pressure--decreased GFR--decreased NaCl across teh macula densa--granular cells secrete renin--increased renin

Front 168

what is the ultimate goal of Ang II?

Back 168

increase blood pressure

Front 169

what is the major effect of AngII on the arteriole?

Back 169

vasoconstriction--increased TPR

vasoconstirction (of afferent and efferent arteriole)--maintained GFR--Maintianed filtered load of Na

Front 170

what is the major effect of AngII on the cardiovascular contorl center in teh medulla oblongata?

Back 170

increased CV response--increased TPR--increased BP

Front 171

what is Ang II's overall effect on the hypothalamus?

Back 171

increased ADH--increased TPR (in vasa recta)

increased ADH--increased H20 reabsorbtion--increased ECF--increased BP

increased thirst--increased ECF--increased BP

Front 172

what is Ang II's overall effect on the adrenal cortex?

Back 172

increased aldosterone--more ENaC channels in the collecting duct--increased Na reabsorption--decreased Na excretion--increased ECF--increased BP

Front 173

what is Ang II's affect on the proximal tubule?

Back 173

increased Na reabsorption--decreased Na excretion--increased ECF--increased BP

Front 174

explain teh stimuli, action and mechanism of aldosterone

Back 174

stimlui: increased AngII levels, DECREASED PNa, increased Pk

Actin: increased Na reabsorption by collecting duct

mechanism:genomic placement of ENaC channels, creation of Na-K pumps, and mitochondira enzymes

Front 175

how do catecholamine effect the kindey? (stimlus, action, and mechanims)

Back 175

stimuli: SNS activation

Action: increased Na reabsorbtion by proximal tubule

mechanism: activates Na/H exchanger

Front 176

explain how ANP affects the kidney (stimulus, action, mechanims)

Back 176

stimuli: atrial stretch

action: decreased Na reabsorbtion by collecting duct

mechanism: inhibits ENaC

Front 177

how does ANP affect the hypothalamus?

Back 177

releases vasopressin (ADH)--increases NaCl and H20 excretion

Front 178

how does ANP affect teh kidney itself?

Back 178

increased GFR, decreased renin--increased NaCl and H20 excretion

Front 179

how does ANP affect the adrenal cortex?

Back 179

decreased aldosteorne--increased NaCl and H20 excretion

Front 180

how does the glomerulotubular balance affect the kidney?

Back 180

as RBF increases--there is increased proteins in the plasma--increased plasma colloid pressure--increased reabsorption in teh peritubular capillaries

Front 181

how does the kidney intrinsically regulate sodium excretion?

Back 181

at higher pressure, the sodium excretion in the kidney is higher to get back to resting state. impaired in hypertensive patients

Front 182

explain factors affecting input and output of total body water

Back 182

input: H20 of oxidation, in food, as H20

output:skin and lungs, feces, urine

Front 183

how is dilute urine formed?

Back 183

NaCl and H20 leaves in the proximal tubule--H20 leaves in the descending limb--water imperable the rest of teh way leading to dilute urine

Front 184

how does ADH make more concentrated urine?

Back 184

by placing aquaporin channels on teh collecting duct allowing water to pass out of the nephron

Front 185

explain what happens to urea in the pressence of ADH and without ADH

Back 185

without: most urea is not reabsorbed in teh proximal tubule and excreted in teh urine

with: ADH increases the permeability of H20 and urea (H20 in the proximal collecting duct and the distal collecting duct, urea only in the distal collecting duct). urea reabsoption pulls more water out with it.

Front 186

what are the three processes that must function in concert to give the kidney the ability to produce an osmotically concentrated or dilute urine?

Back 186

GENERATION of interstitial osmotic gradient by countercurrent multiplication in teh loop of henle

MAINTENANCE of interstitial osmotic gradient by coutercurrent exchange in the vasa recta

ADH regulatin of water permeability in teh collecting duct

Front 187

what are the three requirements for the loop of henle to establish the medullary interstital osmotic gradient?

Back 187

counter current flow in adjacent structures

different water pereabiltiy of the adjacent structures having countercurrent flow

source of energy

Front 188

how do loop diuretics work?

Back 188

inhibit NKCC2 which removes the energy source needed for couterncurrent multilication. that causes dissipatin of teh medullary interstitial osmotic gradient

Front 189

what is the net effect of the coutnercurrent exchange of teh vasa recta?

Back 189

minimizes washout of teh medullary interstitial somotic gradient via teh vascular system

Front 190

how does increased medullary blood flow affect the kidneys ability to produce osmotically concentrated urine?

Back 190

decreases efficiency of coutercurrent exchange--medullary solute washout--decreased abiltiy to produce an osmotically conecntrated urine

Front 191

how does decreased medullary blood flow affect the kidneys ability to produce osmotically concentrated urine?

Back 191

increased efficiency of CC exhange--solue retention in teh medulla--increased magnitude of osmotic gradient--increase in ability to produce an osmotically concentrated urine

Front 192

how does ADH affect solute content in the inner medulla?

Back 192

increases urea reabsobtion by teh IMCD--increased solute content

decreased medullary blood flow via constricted vasa recta (decreased solute washout)--increased solute content

Front 193

explain how ADH is stimulated in the pitutiary gland and what it affects

Back 193

decreased blood volume or increased blood osmolarity are sensed by receptors--cause vasopressin release--causes kidney to retain water which causes either increased volume to normal limits or decreased osmolarity to normal limits

Front 194

explain how changes in osmolarity and blood volume affect ADH

Back 194

small increases in osmolarity cause increases in ADH. large changes in BV are needed to cause ADH outputs but those outputs are much larger than those for plasma osmolarity

Front 195

what 5 things cause increased ADH secretion?

Back 195

nausea, vomiting, morphine, nicotine, cyclophosphamide

Front 196

what three things cause a decrease in ADH secretion?

Back 196

alcohol, antihypertensive drugs, dopamine blockers

Front 197

‐ is the volume of plasma from which a substance is completely removed by the kidney in a given
amount of time (usually a minute).

Back 197

renal clearance