kidneys fluid regulation electrolytes

8/19/2019 Kidneys Fluid Regulation Electrolytes

1/10

1. K level in ECF 4.2 mEq / L

2. K level in ICF 140 mEq / L

3. hypokalemia

level

< 3.5 mEq / L

4. hyperkalemia

level

> 5.0 mEq / L

5. effects of

hyperkalemia

depolarization

(less conc delta)

accelerated repolarization

rests closer to threshold

-will fire w/ less stimulus arrhythmia,

fibrilation

-or block (inact gates not open)

6. effects of

hypokalemia

hyperpolarization

(inc conc delta)

delayed repolarization

higher stim needed to reach threshold

fatigue, muscle weakness

hypoventilation

7. ECF, ICF

uptake, secretion

ECF = uptake (reabsorption)

ICF = secretion (after basal side diffuses

out to lumen)

8. aldosterone

impact on K

secretion

Increases it

Na exchanged for K - at pumps

9. Primary

aldosteronism

too much aldosterone

10. Insulin

effect on K conc

in ECF

effect on

secretion

DECREASE K in ECF

Hypokalemia

(shifts from ECF to ICF)

INCREASES SECRETION

11. Aldosterone

effect on K conc

in ECF

effect on

secretion

DECREASE

Hypokalemia


INCREASES SECRETION

12. Beta adrenergic stim

effect on K conc in ECF

effect on secretion

DECREASE

Hypokalemia


INCREASES SECRETION

13. Alkalosis


DECREASE

Hypokalemia


INCREASES SECRETION

14. Cell lysis


INCREASE

(shifts from ICF to ECF)

15. Acidosis


INCREASE

HYPERKALEMIA

DECREASES SECRETION

16. Strenuous exercise


INCREASE

HYPERKALEMIA

DECREASES SECRETION

17. Distal tubule VOLUME

decrease - general

(GFR decrease)

DECREASED SECRETION

HYPERKALEMIA

18. increased ECF Na

osmolarity

hyperosmolarity


INCREASE

Na pulled out, K exchanged at

pumps

(shifts from ICF to ECF)

HYPERKALEMIA

DECREASES SECRETION

19. Distal Tubule (ICF)

Inc Na osmolarity

effect on K secretion

INCREASES SECRETION

(high lumen Na conc, aldosteroneworks to conserve Na, exchanges K)

20. where in renal tubules

is most K reabsorbed

65% in proximal tubule

(but doesn't vary much - most

variation in excretion due to

secretion)

21. % of K excreted

in distal & collecting

tubules

1/3

(of 92 mEq day total excreted)

(by principal cells)

Combined Fluid Reg, Kidneys, ElectrolytesStudy online at quizlet.com/_21vxgj


2/10

22. Potassium

secreted or

absorbed at

Principal Cells

either

into ICF = secretes (by d iffusion)

out to ECF = reabsorbed (after d iffusion)

23. acute acidosis

impact on K

secretion

DECREASES K secretion

(opposes H in ECF opposes Na pump into

ECF, K doesn't go into ICF)

24. acute

alkylosis

impact on K

secretion

INCREASES K secretion

(lack of H enables more Na to pump into ECF,

more K goes into ICF)

25. chronic

acidosis

impact on K

excretion

INCREASES K secretion

(long term - as H+ excess inhibits Na/H20

reabsorption at proximal tubu le - which

increases distal VOLUME, which then

STIMULATES K secretion)

26. Inc K+ in ECF

impact on K

secretion

STIMS Aldosterone ->stims Na/K pumps into

ICF

inc K into principal cells

(then diffuses out to lumen)

key regulator of K!

27. in potassium

depletion

what cells

take action

intercalated cells

when no more K to secrete, increases

reabsorption

by K /H ATP pumps

28. Addison's

disease

too little aldosterone

29. Addison's

disease

causes hypo

or hyper

kalemia

HYPERKalemia

(doesn't stim K secretion)

30. primary

aldosteronism

too much aldosterone

31. Primary

aldosteronism

causes hypo

or hyper

kalemia

HYPOkalemia

(secretes too much K)

32. acute acidosis

vs

chronic acidosis

impact on K+ levels

acute - decreases excretion of K

chronic -increases excretion of K

(net loss of K)

33. effect of increased Na

intake

on renal excretion of K

NONE

decreased aldosterone

(decreased K secretion)

&

high tubular flow rate

(increased K secretion)

cancel eachother out

34. Aldosterone

Acts on Na, K

CONSERVES SODIUM -

decreases secretion-STIMULATES reabsorption of

Na from Lumen

-STIMULATES PUMP out of Na to

interstitial

....Stimulates SECRETION of K

35. Serum calcium level 8.5 - 10.2 mg/ dL

36. Hypocalcemia causes increased excitability

nerves/muscles....tetany

37. Hypercalcemia causes depressed muscle excitability

cardiac arrhythmia

38. % of total serum Ca

ionized vs bound

50% ionized

10% non ionized

40% bound to plasma proteins

39. pH effect on Ca binding to

protein

pH inc (alkalosis) INCREASES

binding

decreases reabsorption

CAUSES hypocal - TETANY

40. Calcium levels balanced

by

excretion in feces 90%

regulation by PTH

41. in kidneys, calcium is FILTERED

REABSORBED

(but not secreted)

42. Renal calcium excretion = Filtered - reabsorbed


3/10

43. Calcium reabsorption

mostly in

proximal tubules

(similar to Na+)

44. PTH secreted by what in

what conditions

by Parathyroid glands

sensing low

Ca

45. PTH hormone feedback does

what (3)

PTH stimulates Ca release

from bonePTH stimulates Ca

reabsorption in Kidn ey

PTH stimulates D3

D3 stimulates Ca

reabsorption in intestine

46. PTH hormone acts where in

tubules

inc Calcium reabsorption

at Henles & DCT

DECREASES EXCRETION

47. Calcium excretion vs

plasma phosphate levels

increased plasma phosphate

stimulate PTH secretion

DECREASES CA excretion

48. Calcium excretion at low pH reabsorption stimulated by

ACIDOSIS

CA excretion DECREASED by

ACIDOSIS

49. Impact on calcium excretion

inc PTH

DECREASED Ca excretion

(Ca reabsorbed)


reduced ECF vol


(Ca reabsorbed)


reduced blood pressure


(Ca reabsorbed)


increased plasma phosphate


(Ca reabsorbed)


Vit D3 activated


(Ca reabsorbed)

54. Calcium storage sites 99% bones

1% in ICF

0.1% in ECF

55. Phosphate excretion

mechanism

overflow when conc above

0.8 mM / L

(typically always Phosphate

in urine)

56. PTH generally

produces

Bone Resorption

both Ca & PO4 go serum BUT

INHIBITS renal P04 reasorption

INCREASE in serum CA

DECREASE in serum PO4

57. Plasma PTH

impact on Phosphate

secretion

INCREASED EXCRETION

58. Mg Conc in ECF causes INCREASED Mg

excretion

59. ECF volume expansion

causes

INCREASED Mg

EXCRETION

60. Ca Conc increase in

ECF causes

Increased Mg EXCRETION

61. Sensors for ADH at atria

(but ADH released from post

pituitary)

62. ADH AKA VASOPRESSIN

63. Sensor for ANP at atria

(and ANP released from atria)

64. ANP secreted by what

when

released from atria in response to

vol, press65. Atrial Natriuretic

Hormone

effect

causes relaxation of smooth muscle

(Decreased TPR)

increased EXCRETION of Na/H20 at

kidneys

inhibits RENIN secretion

66. heart failure cycle

67. Normal pH range 7.2 - 7.4


4/10

68. Na conc vs H conc in ECF 3.5 MM X MORE Na than

H

in ECF

69. Akylosis range pH > 7.4

70. Acidosis range pH < 74

71. 3 buffer systems of body chemical

lungs

kidneys

72. Bicarbonate buffer equation H20 + CO2 H2CO3

H+ + HCO3-

73. Phosphate buffer equation

(renal)

HPO4-- + H+ H2PO4-

74. Ammonia buffer equation

(renal)

NH3 + H+ NH4+

75. Protiens buffer equation

(intracellular)

H+ + Hb HHb

76. what percentage of buffering

occurs inside of cells

60-70%

77. Thirst regulated by Baroreceptors

(aortic arch & carotid

sinus)

Juxtaglomerular app -

KIDNEY

(to ANG II - stim hypothalthirst)

Osmoreceptors -

HYPOTHALAMUS

78. RENIN

DOES WHAT

converts Angiotensigen

(from Liver)

to Angtiotensin I

79. Angiotensin I

converts to what

Angiotensin I I

w/ ACE(from cap beds of

LUNGS)

80. RENIN

secreted where

juxtaglomerular cells

(when reduced

stretch/FLOW detected)

81. Angiotensin II

EFFECTS (4)

VASOCONSTRICTION SHORT

ACTING

PERIPHERAL RESISTANCE

INCREASED - BP INC

INCREASES ALDOSTERONE

(acts on adrenal cortex)

INCREASES ADH(acts on pituitary)

CONSERVES Na

(directly via Na/H exchange)

STIM THIRST

(at hypothal)

82. ANGIOTENSIN II

VASO EFFECT on

KIDNEY

EFFERENT VASOCONSTRICTOR

(LESS FLOWS OUT OF GLOMERULUS)

INCREASES GFR

(no effect on afferent - protected**)

83. ANGIOTENSIN II

Impact on Adrenal

Cortex

SECRETES

Aldosterone

84. ANP

effect

inhibit reabsorption of Na & H20

inhibits Renin

85. ANP

produced by

cells of cardiac atria

under stretch

86. Aldosterone secreted

from

adrenal cortex

87. Aldosterone effect at principal cells - stims Na pumps

INCREASES RATE OF Na

REABSORPTION

Conserves Na

(increases water retention -

indirectly)

incr K secretionincr H secretion

88. Disease of no

aldosterone

Addison's

89. Increased plasma K+

levels

EFFECT ADRENAL

CORTEX

HOW

STIMULATE

ALDOSTERONE

(decreases Na loss)


5/10


6/10

112. Between

Intra & Extra

CELLULAR

regulated by

Osmotic effects

(Smaller solutes, electrolytes)

(cell membrane IMPERMEABLE to even

small IONS)

113. Intra & Extra

CELLULAR

Tonicity

Maintained

ISOTONIC

water moves across rapidly

114. osmoles number of osmotically

ACTIVE particles in a solution

(not just molar concentration)

115. 1 molar NaCL

osmolar conc =

2 osm/L

116. osmolality

vs osmolarity

osmoles per kg of water

osmolarity - osmoles per liter

(dilute sol such as body fluids, are same)

117. Van Hofts Law

(calc osmotic

pressure)

use Van Hofts coeff:

19.3 mm Hg / mOsm/L

(techn needs correction factor too)

118. ECF volume 14 L

119. ICF volume 28 L

(2x)

120. Isotonic saline

osmolarity

280 mOsm/L

121. isotonic Normal

Saline

Glucose

0.9% Saline

5% Glucose

122. Osmolarity

isotonic Normal

Saline

280 mOsm

(per L iter)

(0.9 %)

123. calculating volume

changes

adding Y Liters of

X % NaCl solution

(to ECF)

-mOsm in each ECF, ICF

(3900, 7800)

+added to ECF (L x 280)

-calc new total conc (mOsm /

vol - ECF, ICF, +added)

-calc vols ECF, ICF(using new conc & known

solutes)

124. -natremia caused by

loss of sodium

Hyponatremia - dehydration

125. loss of sodium

"Hyponatremia -

dehydration"

hypo/hyper natremia

impact to ECF, ICF

Na lost , conc decreases

(hyponatremia)

water out w/ it - dehydration

of ECF

ECF dec

hyp o - fluid goes in

ICF inc

126. causes of primary loss of

sodium - dehydration

"Hyponatremia -

dehydration"

Adrenal insufficiency

(aldosterone dec), Addisons

Diuretics

Diarrhea, Vomiting


water retention

"Hyponatremia -

overhydration"

128. water retention

"Hyponatremia -

overhydration"

hypo/hyper natremia

impact to ECF, ICF

overhydration - causes dec

Na conc

HYPOnatremia

ECF inc (directly)

HYPO - fluid goes inside

cell/swells

ICF inc

129. causes of water retention -

overhydration

"Hyponatremia -

overhydration"

Excess ADH

bronchogenic tumor


loss of water

"Hypernatremia -

dehydration"


7/10

131. loss of water

"Hypernatremia -

dehydration"

hypo/hyper natremia

impact to ECF, ICF

dehydration - Na conc inc

HYPERnatremia

ECF dec (directly)

HYPER - fluid comes out of

cell/shrinks

ICF dec

132. causes of primary loss

of water - dehydration

Diabetes insipidus (low ADH)

excessive sweating

inadequate water intake


excess sodium

"Hypernatremia - overhydration"

134. Excess sodium

"Hypernatremia -

overhydration"

hypo/hyper natremia

impact to ECF, ICF

Na gained , conc inc

(HYPERnatremia)

ECF inc (some w/ Na bu t notenough)

HYPER - fluid comes out of

cell/shrinks

135. causes of excess

sodium -

overhydration

Cushing's disease

Primary aldosteronism

(Conn's syndrome)

136. consequences of

HYPONATREMIA

cell swelling - EDEMA

brain can't grow > 10% - else

herniates through foramen

magnum

137. less common hyper or

hyponatremia

hypernatremia

(intense thirst prevents)

138. how ISCHEMIA causes

cell swelling

EDEMA

lack of nutrients

Na/K pump slows - Na builds up

inside w/ water

(tissue vol can increase 3x)

prelud e to death of tissue

139. intracellular edema

caused by

HYPOnatremia

depressed metabolism or

ischemia/nutrients

(less Na/K pump activity)

inflamm/capillary perm

140. extracellular edema

caused by

abnormal leakage from capillaries

(inc bp, inc perm, DEC proteins)

lymphatic deficiency

141. safety factors

preventing edema

COMPLIANCE low at neg pressures

LYMPH flow can INCREASE 10-50x

"WASHDOWN" reduces interstitial

colloid osmotic pressure

142. compliance low at

negative pressure

due to

proteoglycan filaments hold fluid in

"gel"

at negative interstitial pressure

3mm safety factor

143. pitting edema

caused by

accumulation of (non gel)

free fluid - brush pile separates

(at positive interstit pressure)

144. additional function

of

proteoglycan

filaments

"spacer" - ensure space between

cells, so nutrients & ions can diffuse

readily

(ions don't diffuse through cell

membranes)

(filaments DON'T hinder

nutrient/waste d iffusion)

145. pitting edema

relieved by

elevation - gravity will aid flow back

through channels

146. lymph can increase

by

10-50x

147. "washdown" of

interstitial fluid

inc lymph flow, greater pull of

protein to lymp

(lymph vessels permeable to protein,

caps not)

less protein in interstitial space

causes dec vac/suction

(decreased colloidal pressure) on

capillary fluid

148. Pressure "safety

factor" before

EDEMA

17mm Hg capillary p ressure buffer

(2X normal - net inward venous

capillary 7mm Hg)


8/10

149. pressures:

capillary, venous (& nets)

BCOP

blood colloid osmotic pressure

- 28

cap - 41mmHg ven - 21mmHg

(net +13 - flows out) (net -7 -

flows back in)

lymph - net - 0.3mm Hg diff

stays in Interstitial(then into lymph vessel - one

way valves)

150. lymphatic system - would

die without why

returns proteins to blood

(capillaries not permeable)

151. amount of fluid leaving

caps

entering lymph

fraction, Liters per day

1/10

2-3 L per day

152. fluid moves through

lymphatic capillaries how(2)

capillary p ump

external (muscles, movement,

pulsation)

one way valves

153. how does edema occur interstitial tissue loses vacuum

154. pressures in potential

spaces

NEGATIVE -

-3 to -5 JOINTS

-5 to -6 PERICARDIUM

-7 to -8 Pleural Cavity

155. EDEMA in tissue adjacent

to potential

spaces/cavities

flows into spaces

EFFUSION

156. pressure at glomerular

capillaries

60 mm Hg

157. pressure at peritubular

capillaries

13 mm Hg

158. macula densa location on distal tubule

(but measures pressure at

afferent arteriole)

159. type of nephron w/ vasa

recta

juxtamedullary

160. juxtaglomerular

apparatus

consists of

juxtaglomerular cellls on

AFFERENT arteriole (incoming)

macula densa cells on DISTAL

TUBULE (filtrate side)

161. JG cells sense STRETCH (pressure)

Afferent Arteriole (incoming)

162. Macula densa senses Sodium level - filtrate

(at distal tubule)

163. blocked ureter - Pain

causes

reflex constriction of ureter

164. uretorenal reflex pain also causes sympathetic

reflex at

Kidney arterioles

(constricting renal arterioles)

reduces fluid into pelvis w/

blocked ureter

165. smooth muscle of

bladder begins to

contract at fluid level

200ml

166. composition of filtratesimilar to

plasma

(except Ca, FA's lower - partially

bound to proteins)

167. molecules passing

through filter

sodium

glucose

inulin

(not large proteins)

168. positive vs negative

charged

particles passing through

filter of capsule

positively charged molecules

more frequently filtered

169. can cause proteins to pass

through

loss of negative charge on

basement membrane

protein/albuminuria

170. microalbuminuria

levels

protein between 25 - 150 mg

albumin

( per day)

171. causes of

microalbuminuria

early diabetes

(10-20X to dev persistent

albuminuria)

hypertension

glomerular hyperfiltration


9/10

172. GFR glomerular flow rate

portion of Renal Plasma flow

pushing through Bowman's

capsule

173. Filtration Fraction GFR / Renal Plasma Flow

174. GFR typically 180 L / day

125 ml / min

175. Plasma volume &

Turnover rate

3 L

60 cycles / day

176. Filtration Fraction

typically

.2

20%

177. kidney relative blood

supply

vs brain

7X flow

(w/ only 2X oxygen consumption)

178. Net filtration pressure

equation

Glom Hydrostatic Pressure

LESS

- Glom Oncotic (suck back into

Glom)

- Bowman's Hydrostatic (opposing)

PLUS (if any)

- Bowmans Oncotic (suck back into

bowman)

179. Normal Glomerular

Hydrostatic Pressure

60 mm Hg

180. Normal Glomerular

Oncotic Pressure

32 mm Hg

181. Normal Bowman's

Hydrostatic Pressure

18 mm Hg

182. Normal net filtration

pressure

(of Glomerular

Capsule)

+ 10 mm Hg

(flow out of Glomerular into

Bowman/tubule)

183.

Impact of filtrationfraction on

glomerular colloid

osmotic pressure

proportional

inc in filtration fraction -> inc prot

conc

inc colloidal pressure (suction back

into glomerulus)

184. impact of

CONSTRICTING

AFFERENT arteriole

(incoming)

reduces pressure (in glomerulus)

reduces GFR

185. impact of

CONSTRICTING

EFFERENT

arteriole

(outgoing)

modest/ < 3X - increases pressure (in

glomerulus)

INCREASE GFR

SEVER > 3X - protein buildup colloidal suctio

REDUCES GFR

186. renal oxygen

consumption

varies

in proportion

to

sodium reabsorption

(active transport)

187. Renal blood

flow

determined by

pressure gradient

vascular resistance

188. Renal blood

flow equation

= Renal artery pressure - Renal vein

pressure

_____________________________________________Total Renal Vasc Resist

(Flow = MAP / TPR )

189. kidneys

AUTOREGULATE

renal blood

flow & GFR to

what ARTERIAL

pressure range

80 - 170 mm Hg

190. SYMpathetic

activation

(or norepi, epi)

IMPACT ON

GFR, renal

blood flow

only SEVERE act - else little/none

(hemorrhage, brain ischemia)

DECREASES renal blood flow & GFR

(constricts arterioles)

191. Angiotensin II

IMPACT ON

GFR, renal

blood flow

ACTS on WHAT

DECREASE blood flow & GFR

192. Angiotensin II

afferent vs

efferent effects

-Renal blood flow overall constricted

-but EFFERENT only constricted

(afferent is protected - so backflow at

glom...hydrostatic pressure actually inc)

193. Angiotensin II

preferentially

constricts...

EFFERENT

(outgoing - forces more fluid into bowman)


10/10

194. endothelin

IMPACT ON GFR, renal

blood flow

DECREASE

blood flow & GFR

195. NO


blood flow

INCREASES

renal blood flow & GFR

196. Prostaglandin


blood flow

INCREASES


197. Bradykinin


blood flow

INCREASES


198. High protein


blood flow

INCREASES


199. High blood glucose

(DM)


blood flow

INCREASES


200. NSAIDS

IMPACT ON GFR

DECREASES GFR

(esp volume depleted states)

201. Fever

Pyrogens

IMPACT ON GFR

INCREASES GFR

202. Glucocorticoids

IMPACT ON GFR

INCREASES GFR

203. Aging

IMPACT ON GFR

DECREASES GFR

(10% /dec after 40 yrs)

204. Macula densa

senses & controls

senses NaCL level at DCT

1 -DILATEs AFFERENT (directly)

2 -SECRETES RENIN

205. Macula Densa

NaCl level low

(at DCT)

Means LOW GFR

MD acts to

- DILATE AFFERENT arterioole (inc

flow in)

- secretes Renin - > Ang II - >

CONSTRICTS EFFERENT

NET INC GLOM PRESSURE = GFR

206. Macula Densa

Sense Low NACL

ACTS

DILATES AFFERENT - (more into GLOM)

CONSTRICTS EFFERENT - (less out of

GLOM)

(via Renin/AngII)

207. Filtration

Reabsorption

Secretion

Excretion

Creatinine

Filtration Only

(all is excreted that is filtered)

ER = FR

208. Filtration

Reabsorption

Secretion

Excretion

Electrolytes

Partial Reabsorption

ER = FR - RR

209. Filtration

Reabsorption

SecretionExcretion

Aminoacids

Complete Reabsorption

(all that is filtered is reabsorbed)

ER = 0

210. Filtration

Reabsorption

Secretion

Excretion

Glucose

Complete Reabsorption

(all that is filtered is reabsorbed)

ER = 0

211. Filtration

Reabsorption

Secretion

Excretion

Organic

Acids/Bases

DRUGS

Secretion

(secreted from blood)

ER = FR + SR

kidneys fluid regulation electrolytes

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