Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BRS (PHYSIO) > RENAL and ACID-BASE > Flashcards

RENAL and ACID-BASE Flashcards

1
Q

Total body wayer is approximately ___________

A

60% of body weight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The percentate of TBW is higherst in ___________

A

newborns and adult males

  • Lowest in adult females
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

2/3 of TBW

A

Intracellular Fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Major cations of ICF are _______

A

Potassium and Magnessium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The major anions of ICF are

A

Protein and organic phosphates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

1/3 of TBW

A

Extracellular fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The major cation of ECF is ________

A

sodium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The major anions of ECF are ______ and _________

A

Chloride and HCO3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

______ is 1/4 of ECF

A

Plasma

(the major plasma proteins are albumins and globulins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

_________fluid is 3/4 of the ECF

A

Intestitial fluid

  • The composition is the same as that of plasma except that it has little protein
    • Ultrafiltrate of plasma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

A known amount of a substance is given whose volume of distribution is the body of fluid compartment of interest

The substance is allowed to equilibriate

The conentration is measured an the volme of distribution is calculated

A

Dilution method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

______ marker for TBW that distributes wherever water is found

A

titrated water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

_______marker for ECF because it is a large molecule that cannot cross cell membranes and is therefore excluded from the ICF

A

Mannitol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Marker for plasma volume because it is a dye that inds to albumin and is therefore confined to the plasma compatment

A

Evans blue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Body water and ody fluid Compartments

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Concentration of solute particles

A

Osmolarity

Plasma osmolarity is estimated as :

2 x Na + glucose/18 + BUN/2.8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

At steady state, ECF osmolarity and ICF osmolarity are _____________

A

equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

To achieve osmolarity equality ________ shifts between ECF and ICF

A

water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Infusion of isotonic NaCl (addition of isotonic fluid)

A

also called as isosmotic volume expansion

  • ECF volume increase, but bo change occurs in the osmolarity of ECF or ICF
  • Plasma protein concentration and heamtocrit decreases
  • Arterial blood pressure increases due to ECF volume increases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Diarrhea - loss of isotonic fluid

A

also called as isosmotic volume contraction

  • ECF volume decreases, but no change occurs in the osmolarity
  • Plasma portein concentraion and hematocrit increases because of loss of ECF concentrates the portein and RBCs
  • Arterial blood pressure decrease because ECF volume decreases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Excessive NaCl intake - addition of NaCl

A

Also caled hyperosmotic volume expansion

  • Theosmolarity of ECF increases because osmoles (NaCl) hace been added to the ECF
  • Water shifts from ICF to ECF. As a result of this shift, ICF osmolarity increases until equals that of ECF
  • ECF volume increases and ICF volume decreases
  • Plasma protein concentration and hematocrit decrease because of theincrease in ECF volume
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Changes in voume and Osmolarity of body fluids

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Sweating in a desert - loss of water

A

Also called as hyperosmotic volume contraction

  • The osmolarity of ECF increases because swert is hyposmotic (relatively more water than salt is lost)
  • ECF volume decreases because of the loss of volume in the sweat. Water shits oit of the ICF, ICF osmolarity increases and ICF volume decreases
  • Plasma protein concnetration increases because of the decrease in ECF volume. Although Hematocrit might alsobe expected o increase, it remains unchanged because water shifts out of the RBCs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

SIADH - gain of water

A

Hyposmotic volume expansion

  • the osmolarity of ECF decreases because excess water is retained
  • ECF volume increases. Water shidts in to thecells, ICF osmolarity decreases until it equals ECF. ICF volume increases
  • Plasma protein concentration decreasesbecause of the increase in ECF volume. Hematocrit remains unchanged because water shifts into theRBCs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Adrenocortical insufficiency - loss of NaCl

A

also called hyposmotic volume contraction

  • The osmolarity of ECF decreases. asa result of the lackof aldosteron, theere is decreased NaCl reabsorption. Kidney excrete more NaCl than water
  • ECF volume decreases. water shifts into the cells; asaresult of this, ICF osmolarity decreases until it equals ECF osmolarity and ICF volume increases
  • Plasma protein concentration increases because of the decrease inECF volume. HCT increases
  • Arterial blood pressure decrease because of the decrease in ECF volume
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Indicates the volume of plasma cleared of substance per unit time

A

Clearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

RBF is ______% of the cardiac output

A

25%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

RBF is _______ proportional to the pressure difference between the renal arter and the renal vein

A

Directly propotional

  • inversely proportional to the resistance of the renal vasculature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

__________of arterioles leads to decrease in RBF

A

Vasoconstriction

  • produced by the activation of the sympathetic nervou system and angiotensin II
    • at low concentration, ATII preferentially constricts efferent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

____________ dilate efferent arterioles and produce decrease in GFR

A

Angiotensin converting enzyme inhibitors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

_________of renal arteriole leads to an increase in RBF produced by prostaglandin E2 and I2, bradykinin ,nitric oxide, and dopamine

A

Vasodialtion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

causes vasodialtion of the afferent arterioles and to a lesser extent, vasoconstriction of efferent arterioles

A

Atrial natriuretic peptide

overall, ANP increases RBF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Autoregulation of RBF is accomplished by _________

A

changing renal vascular resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

RBF remains constant over the range of arterial pressure from ___________

A

80 to 200 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Mechanisms for Autoregulation of RBF

A

Myogenic

Tubuloglomerular feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

_______________in wich the renal afferent arterioles contract in response to stretch. Thus increased renal arterial pressure stretches the arterioles, which cobtract and increase resistance to maintain constant blood flow

A

Myogenic mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

_____________in which, inreased renal arterial pressure leads to increased delivery of fluid to the macula densa. The macula densa senses the increased load and causes constriction of the nearby afferent arteriole, increasing resistance to maintain constant blood flow

A

Tubuloglomerular feedback

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Clearance of _______ is used to measure Renal Plasma flow

A

para-aminohippuric acid (PAH)

  • Meaures effective PAH and understiamtes true RPFby 10%
  • Clearance of PAH does not measure renal plasma flow to regions pf the kidney that do not filter and secrete PAH, such as adipose tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Measurement of RBF

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

________ isused to measure GFR

filtered but not reabsorbed or secreted by renal tubules.

A

Inulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Both BUN and serum creatinine ______ when GFR decreases

A

Increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

_______ azotemia, BUN increase more than serum creatinine and there is an Increased BUN/creatinine ration (>20:1)

A

Prerenal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

GFR ____ with age

A

Decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

The fraction of RPF filtered across the glomerular capilalries

A

Filtration fraction

FF = GRR/RPF

  • normally about 0.20
    • the remaining 80% leaves the glomerular capillaries by the efferent arterioles and becomes the peritubular capillary circulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

______in the filtration fraction increases the protein concentraion of peritubilar capillary blood, which leadds to increased reabsorption in the proximal tubule

A

Increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

________in the filtratin fraction produce decrease in the protein concentration of peritublar capillary blood and decreased reabsortpion in the proximal tubule

A

Decrease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

The driving force for glomerular filtration is _______across the glomerular capillaries

A

net-ultrafiltration pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

_______is always favored in glomerular capillaries because the net ultafiltration pressure always favor the movement of fluid out of the capillary

A

Filtration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

GFR can be expressed by the __________

A

Starling equation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

____ is filtration across the glomerular capillaries

A

GFR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Kf is the________ of the glomerular capillaries

A

filtration coefficient

  • The glomerular barrier consists of
    • capilalry endothelium
    • basement membrane
    • filtation slits of the podocytes
  • Normally, anionic glycoproteins line the filtration barrier and restrict the filtration of plasma proteins, which are also negatively charged
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

PGC is _____________ which is constat along the length of the capillary

A

Glomerular capillary hydrostatic pressure

  • Increased by dialtion of the afferent arteriole or constriction of the efferent arteriole
  • Increase cause increase in net ultrafiltration pressure and GFR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

πGC is ____________. It is usually zero, and therefore ignored,

A

bowman space oncotic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Effects of changes in Starling forces on GFR, RPF, and Filtration Fraction

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

the difference between the aamount filtered across the glmerular capilalried and the amount excreted in urine

A

Reabsirption or secretion rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

If filtered load is greater than the extretion rate, then ___________ has occured

A

net reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

If the filtered load is less than the excretion rate, then _______ has occured

A

net secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Filtered load of glucose ____________ in direct proportion to the plasma glucose concentration

A

Increases

(filtered load = GFR x P )

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Na-glucose cotransport in the ___________ reabsorbs glucose from tubular fluid into the blood.

A

Proxximal tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

The reabsorptive rate at which the carriers are saturated is the _______

A

Tm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Defined as the plasma concentration at which glucose first appears in the urine

A

Threshold

(Approximately 250 mg/dL)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

The region of the glucose curves between the threshold and Tm

Occurs between plasma glucose of approximately 250 and 350 mg/dL

A

Splay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Represents the excretion of glucose in urine before saturation of reabsorption is fully achieved

A

Splay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

filtered load of PAH __________ in direct proportion to the plasma PAH concentration

A

Increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Secretion of PAH occurs from peritubular capillary blood into tubular fluid (urine) via carriers in the _________

A

Proximal tubule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Excretion of PAH is the _________ across the glomerular capillaries plus __________ from peritubular capillary blood

A

Sum of filtration

Secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

RPF is measure by the clearance of PAH at plasma concentrations of PAH that are _________ than at Tm

A

lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Substances with the _________ clearances are those that are both filtered across the glomerular capillaries and secreted from the peritubular capillaries into urine

A

highest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Subsances with ______ clearances are those that either not filtered or are filtered and subsequently reabsorbed into peritubular capillary blood

A

Lowest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Substance with clearances equal to GFR

A

glomerular markers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Have an HA form and A form

A

weak acids

  • The HA form which is uncharged and lipid soluble can “back-diffuse” from urine to blood
  • the A form, which is charged and not lipid soluble cannot “back diffuse”
72
Q

Weak acids at ________, the HA form predominates. there is more back diffsuion, and there is increased excretion of the weak acid.

A

Acidic urine

73
Q

Have an BH form and a B form

A

weak bases

  • the B form, which is uncharged and lipid soluble, can back-diffuse from urine to the blood
  • The BH form is charged and not lipid soluble cannot back diffuse
74
Q

_______ is urine at any point along the nephron

A

Tubular fluid

75
Q

Plasma is systemic Plasma . It is considered ______

A

constant

76
Q

comapres the concentration of a substance in tubular fluid at any point along the nephron with the concentration in plasma

A

TF/P ratio

77
Q

if Tf/P = ____.then either there has been no reabsorption of the substance or reabsoprtion of the substance has been exactly proportional to the reaborption of water

A

1.0

78
Q

IF TF/P is __________ then reabsorption of the substance has been greater than the reabsorption of water and the concentration in tubular fluid is less than that in plasma

A

<1

79
Q

If TF/P is _______ then eeither reabsorption of the substance has been less than the reabsorption of water or there has been secretion of the substance

A

>1.0

80
Q

used as amarker for water reabsorption along the nephron

Increases as water is reabsorbed

A

TF/Pinulin

  • The following equation shows hw to calculate the fraction of the filtered water that has been reabsorbed
81
Q

Corrects the TF/Px ratio for water reabsorption. this double ratio gives the fraction of filtered load remaining at any point along the nephron.

A

[TF/Px] / [TF/Pinulin] ratio

82
Q

Sodium is ______along the entire nephron, and very little is excreted

A

Urine

83
Q

Sodium handling along the nephron

A
84
Q

Reabsorbs 2/3 or67% of the filtered sodium and water

Site fo glomerulotubuluar balance

A

Proximal tubule

85
Q

Mechanism of sodium reabsorption of sodium

A

The process is isosmotic. the reabsorption of sodium and water in the PCT is exactly proportionl. therefore TF/PNa and TF/Posm =1

86
Q

Sodium is reabsorbed by __________ with glucose, amino acids, phosphates and lactate

A

Cotransport

87
Q

Sodium is also reabsorbed by _________ via Na-H exchange. which is linked directly to the reabsorption of filtred HCO3

A

Countertrasnport

88
Q

diuretics that act in the early proximal tubule by inhibiting the reabsorption of filtered HCO3

A

Carbonic anhydrase inhibitors

89
Q

In the late proximal tubule, sodium is reabsorbed with ________

A

Chloride

90
Q

Maintains constant fractional reabsorption )2/3 or 67%)of th filtered sodium and water

A

Glomerulotubular balance in the proximal tubule

91
Q

Mechanism of Glomerulotubular balance

A
  • based on starling forces in the peritubualr capillaries
  • Fluid reabsorption is increased by increase in πc of the peritubilar capillary blood and
92
Q

ECF volume contraction ____________ absorption

A

Increases

  • increases peritubular capillary protein concentraion and πc and decreases peritubular capillary Pc.
93
Q

ECF volume expansion ________ reabsorption

A

Decreases

  • decreases periubular capillary protein concentration and πc and increases Pc
94
Q

TF/ ratios along the proximal tubule

A
  • at the beginning of the proximal tubule, TF/P for freely filtered substance is 1
  • Moving along the PCT, TF/P for sodium and osmolarity remain at 1 because sodium and total solute are reabsorbed proportionately with water
  • Glucose, amino acids and HCO3 are reabsorbed proprotionately more than water, so their TF/P values below 1
  • In the early PCT, Cl is reabsorbed proportionately less than water so its TF/P valueis greater than 1.0
  • Inulin is not reabsorbed so its TF/P value increases steadily avove 1.0 as water is reabsorbed and inulin is left behind
95
Q

Reabsorbs 25% if the filtered Na

contains Na-K-2Cl contransporter

site of action of the loop diuretics

impermeable towater

diluting segment

A

Thick asccending limb of the loop of henle

  • has a lumen positive potential difference
    • some K diffuses back in to the lumen, making the lumen electrically positive
96
Q

togeter rabsorbs 8% of the filtered sodium

A

Distal and collecting duct

97
Q

Reabsobs NaCl by Na-Cl conductance

site of action of thiazide diuretics

impermeabe to water

cortical diluting segment

A

Early distal tubule

98
Q

2 cell types in the late distal tubule and collcting ducts

A

Principal cells

a-intercalated cells

99
Q

Reabsorbs Na and water

Secretes K

Aldoseterone increases sodium reabsorption and increases Potassium secretion

A

Principal cells

100
Q

________________increases water permeability by directing insertion of water channels in the luminal membrane potential

A

Antidiuetic hormone

  • in the absence of ADH, the principal cells are virtually impermeable to water
101
Q

Examples of K sparing diuretics

A

Spironolactone

triamterene

Amiloride

102
Q

secretes H aby an H-ATPase, which is stimulated by aldosterone

Reabsorb Potassium by an H, K ATPase

A

a-intercalated cells

103
Q

Most of the body’s K is locaed in the

A

ICF

104
Q

Potassium is ______, _____, and _______ by the nephron

A

Filtered

Reabsobed

Secreted

105
Q

TF/PK in the Bowman space is ________

A

1.0

Filtration occrs freely across the glomerular capillaries

106
Q

Reabsorbs 67% of te filtered K along with Na and water

A

Proximal tubule

107
Q

Reabsorbs 20% of the filtered K

Reabsorption involves Na-K-2Cl transporter in the luminal membrane of cells

A

Thick ascending limb of the loop of Henle

108
Q

Either reabsobr or secrete K

Depends on dietary K intake

A

Distal tubule and collecting duct

109
Q

Causes of Shift of K out cells (hyperkalemia)

A
  • Insulin deficiency
  • B-adrenergic antagonist
  • Acidosis
  • Hyperosmolarity
  • Inhibitors of Na-K pump (difitalis)
  • Excercise
  • Cell lysis
110
Q

Causes of shift of K into the cells (hypokalemia)

A
  • Insulin
  • B-adrenergic agonists
  • alkalosis
  • Hyposmolarity
111
Q

Reabsorption of K involves ___________ in the uminal membrane of the alpha intercalated cells

A

H-K-ATPase

  • occurs only on low K diet (potassium depletion)
112
Q

Secretion of potassium occurs in the __________

A

Principal cells

  • variable and accounts for the wide range of urinary K excretion.
  • Depends on factors such as dietary K,aldosterone levels, acid-base status, and urine flow rate
113
Q

Potassium handling of nephrons

A
114
Q

Mechanis of distal K seretion

A
  • At the basolateral membrane, K is acively transported into the cell by NA-K pump
  • At the luminal side, K is passively secreted into the lumen through K channels. The agnitude of this passive secretion is determined by chemical and electrical driving forces on K across the luminal membrane
115
Q

Changes in distal Potassium Secretion

A
116
Q

Mechanism of aldosteron in K secretion

A

Involves inreased sodium entry into the cell across the luminal membrane and increased pumping of sodium out of the cells by the Na-K pump. Stimuation of the Na-K pump simulataneously increases K uptake into the principal cells, increaseing the intacellular K concentration andn driving force for K secretion

117
Q

Hyperaldoseronism causes_____________

A

hypokalemia

118
Q

Acidosis ______K secretion

A

Decreases

119
Q

Urea is reabsorbed, secreed in the nephron by ___________

A

Diffusion

  • either simple or facilitated
  • 50% of the filtered urea is reabsorbed in the PCT
  • Urea is secreted into the thin descending limb of LOH
120
Q

Urea cannot pass through the ______, _______, and _________

A

distal tubule, cortical collecting ducts, and outer medullary collecting ducts

121
Q

Stimulates a facilitated diffusion for urea (UT1) in the inner medullar collectin ducts

A

ADH

122
Q

Urea excretion varies with ___________

A

Urine flow rate

  • at high levels of water reabsoption, there is greater urea reabsorption
123
Q

85% of filtered phosphate is reabsobred in the_____________ by ______

A

proximal tubule by sodium -phosphate co transport

124
Q

Inhibits phosphate reabsorption in the PCT

A

PTH

  • Activates adenylate cyclase, generating cyclic AM and inhibiting N-Phosphate co transport
    • causes phosphaturia and increasesd urinary cAMP
125
Q

60% of the plasma Ca is filtered acrosss ________________

A

glomerular capilalries

126
Q

90% og the filtered calcium is reabsorb by passive processes that are coupled to sodium reabsorption in the ____________

A

Proximal tubule and thick ascending limb

127
Q

cause increased urinary calcium excreton

A

Loop diuretics

128
Q

PTH ____________ calcium reabsorption by activating adenylate ylace in the distal tubule

A

increases

129
Q

Thiazide diuretics ________ calcium reabsorption in the early distal tubule

A

increases

  • treatment of idiopathic hyercalciuria
130
Q

Magnesium reabsorb in the ________,_________, and ___________

A

PCT, thick ascending limb, and distal tubule

131
Q

in the _________________ magnesium and calcium compete for reabsorption

A

thick ascending limb

132
Q

Response to water deprivation

A
133
Q

Response to water intake

A
134
Q

Gradient of osmolarity from the cortex (300 mOSm/L) to the papilla (1200 mOsm/L) and is composed primarily of NaCl and urea

A

Corticopapilalry gradient - high ADH

  • established by countercurrent multiplication and urea recylcing
  • maintained by countercurrent exchange in the vasa recta
135
Q

Countercurrent multiplication in the loop of Henle

A
  • depends on NacCl reabsorption in the thick ascending limb and countercurrent flow in the descending and ascending limbs of the loop of henle
  • augmented by ADH
    • stimulate NaCl reabsorption in the thick ascending limb.
136
Q

Urea recycling

A

From the inner medullary collecting ducts into the medullary interstital fluid

Augment by ADH

137
Q

______are the capillaries that supply the loop of Henle. They maintain the corticopapillary gradient by serving as osmotic exchanges

A

Vasa Recta

138
Q

Mechanism for producing hyperosmotic urine

A
139
Q

Production of concentrated urine

A
  1. Corticopapilalry osmoic gradient -high ADH
    • Countercurrent multiplication in the loop og henle
    • urea recycling
    • vasa recta
  2. Proximal tubule -High ADH
    • TF/Posm = 1
  3. Thick ascending limb - High ADH
    • diluting segment
    • Na-K-2Cl contransporter
    • impermeable to H20
    • TF/Posm <1
  4. Early DCT - high ADH
    • cortical diluting sergmen
    • impermeable to water
  5. late DCT - high ADH
    • ADH increaes water permeability
    • TF/P = 1
  6. Colleting ducts - high ADH
    • ADH icnreases water permeability
    • Tf/P >1
140
Q

Production of dilute urine

A
  1. Corticopapillary osmotic gradient - no ADH
    • smaller
  2. PCT -no ADH
    • TF/P = 1
  3. Thick ascending limb LOH -no ADH
    • TF/Posm <1
  4. Early distal tubule - no ADH
    • TF/P, <1
  5. Late distal and collecting ducts - no ADH
    • Impermeable to water
    • TF/P <1
141
Q

Use to estimate the abilty to concetrate or dilute urine

A

Free water clearance

142
Q

urine that is isosmotic to plasma (isosthenuric)

A

CH2O is zero

  • Loop diuretic
    • inhibits NaCl reabsorption in the thick ascending limb, inhibiting both dilution in the thick ascending limb and production of the corticopapillary osmotic gradient
143
Q

Summary of ADH pathophysiology

A
144
Q

Urine that is hyposmotic to plasma (low ADH)

A

CH2O is positve

  • high water intake
  • central diabetes insipidus
  • nephrogenic diabetes insipidus
145
Q

Urine that is hyperosmotic to plasma (High ADH)

A

CH20 is negative

  • Produced in water deprivaton (ADHrelease from the pituitary is stimulated) or SIADH
146
Q

RENAL HORMONES

A
147
Q

Two types of acid produced in the body

A

Volatile and nonvolatile acids

148
Q

Volatile acids

A
  • CO2
  • produced from aerobic metabolism of cells
149
Q

catalyze the reversible reaction between CO2 and H2O

A

Carbonic anhydrase

150
Q

Nonvolatile acids

A

Fixed acids

icnlude sulfuric acids

normally Produced at a rate if 40 to 60 mmoles/day

151
Q

Prevent a change in pH when H ions are added to or removed from a solution

A

Buffer

152
Q

Buffers are most effective within _____pH unit of pK of the buffer

A

1

153
Q

Major extracellular buffer

A

HCO3

pK of CO2/HCO3 bufferpair is 6.1

154
Q

minor extracellylar buffer

most important urinary buffer

A

Phosphate

pK of H2PO4/HPO4 buffer is 6.8

155
Q

Major intracellular buffer

A

Hemoglobin

156
Q

What is a better buffer, deoxyHgb or oxyhemoglobin?

A

Deoxyhemoglobin

157
Q

Henderson-hasselbach equation

A
158
Q

describes how the pH of a buffered solution changes as H+ ions are added to it or removed from it

A

Titration curves

159
Q

A buffer is most effective in the __________ portion of the titration curve, where the addition or removal of H causes little change in pH

A

linear

160
Q

According to the Henderson-Hasselbach equation, when the pH of the solution is ________ to the pK, the concentrations of HA and A are equal

A

Equal

161
Q

Reabsorption of filtered HCO3 occurs primarily in the __________

A

proximal tubule

162
Q

Regulation of filtered load of HCO3

A

Increaes in the filtered load of HCO3 result in the increasse rates of HCO3 reabsorption However, if the plasma HCO3 concentration becomes very high, the filtered load will exceed the reabsorptive ccapacity and HCO3 will be excreted in the urine

163
Q

Increases in PCO2 result in ___________ rates of HCO3 reabsorption

A

Increased

164
Q

ECF volume expansion results in ____________HCO3 reabsorption

A

Decreased

165
Q

Stimulates Na-H exchange thus increases HCO3 reabsorption, contributing to the contraction alkalosis that occurs secondary to ECF volume contraction

A

Angiotensin II

166
Q

Excretion of fixed H+

A
  • Excretion of H as titatable acid (H2PO4)
    • depends on the amount of urinary buffer present and the pK of the buffer
    • minimum urinary pH is 4.4
  • Excretion of H as NH4
    • depends on the amount of NH3 synthesized by renal cells and the urine pH
    • diffusing trapping
167
Q

_______inhibits NH4 synthesis, which produces a decrease in H excretion as NH4 (type 4 RTA)

A

Hyperkalemia

168
Q

Summary of acid -base disorders

A
169
Q

In chronic metabolic acidosism an adapative increase in__________synthesis aids in the excretion of excess H+

A

NH3 synthesis

170
Q

Causes of Acid-Base Disorders

A
171
Q

If metabolic alkalosis is accompanied by ECF volume contraction

A

the reabsortipn of HCO3 increases (secondary to ECF volume contraction and activationof the RAAS), worsening the metabolic alkalosis (contraction alkalosis)

172
Q

Compensatory response to Acid-Base Disorders

A
173
Q

Inhibition of carbonic anhydrase

Proximal tubule

A

Carbonic anhydrase inhibitors (Acetazolamide_

Increase HCO3 excretion

174
Q

Inhibition of Na-K-2CL cotransport

thick ascending limb of the loop of henle

A

Loop diuretics (furosemide, ethacrynic acid, bumetanide)

  • Increased NaCl excretion
  • Increased K excretion (Increase DCT flow rate)
  • Increased Ca excretion (treat hypercalcemia)
  • Decreased ability to concentrate urine
  • Decreased ability ro dilute urine (inhibitin of diluting segment)
175
Q

Inhibition of Na-Cl co transport

Early distal tubule (cortical diluting segment)

A

Thiazide diuretics

  • Increased NaCl excretion
  • Increased K excretion
  • Decrease Ca excretion (treatment for idiopathic hypercalciuria)
  • Decreased ability to dilute urine
  • No effect on the ability to concentrate urine
176
Q

Inhibition of Na reabsorption. Inhibition of K secretion, Inhibition of H secretion

Late distal and collecting duct

A

K-sparing diuretics

  • Ibcreased sodium excretion
  • Decrease K excretion
  • Decreased H excretion
177
Q

Effects of hypoaldosteronism

A

Decreased sodium reabsorption (ECF volume contraction)

Decreased K secretion (volume contraction)

Decreased H+ secretion (metabolic acidosis)

BRS (PHYSIO) (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions