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Flashcards in Renal Q1 Deck (125)
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1
Q

What is the term for Uremic Toxicity due to increased plasma creatinine and BUN (urea)

A

Azotemia

2
Q

Give an example of 2 endogenous waste products excreted by the kidney

A

UREA (aka BUN - Blood Urea Nitrogen)

Creatinine

3
Q

An increase in Angiotensin II will do what?

A

Increase Vasoconstriction

4
Q

An increase in aldosterone will do what?

A

Decrease urinary Na+ excretion

5
Q

What form of Vitamin D does the Kidney produce?

A

1,25 (OH)2 Vitamin D

6
Q

What are 2 consequences of Impaired Renal Function that go hand in hand?

A

Low pH (metabolic acidosis)

High Potassium (Hyperkalemia)

7
Q

What 2 places is Erythropoietin synthesized?

By what transcription factor?

A

Peritubular fibroblasts and Endothelial cells

HIF-1

8
Q

Where does 25 Vita D convert into 1,25 Vita D in the kidney?

What enzyme is involved?

A

Proximal tubule cells

via 1 alpha-Hydroxylase

9
Q

T/F

The kidney is involved in gluconeogenesis

A

True

10
Q

What pH is considered Metabolic Acidosis?

What Potassium level is considered Hyperkalemic?

A

pH 4.0 mEq/L

11
Q

What does a decrease in 1,25 VitaD cause?

A

Calcium Phosphate imbalance and Bone Fractures

12
Q

What does Plasma Protein Imbalance cause?

A

Edema

excess interstitial fluid

13
Q

T/F

Impaired renal function can decrease the immune system

A

True

14
Q

T/F

Impaired renal function can cause Anemia

A

True

Decreases Erythropoietin synthesis

15
Q

What is Renal functional reserve capacity?

What is the lower limit of fluid homeostatic maintenance?

At what point does the patient need dialysis?

A

Kidney can maintain GFR (glomerular filtration rate) at reduced function

20%

10-15%

16
Q

What percentage of adults have some form of kidney disease?

A

10%`

17
Q

Name 3 causes of Acute Renal Failure (ARF)

A

Pre-renal (decrease renal blood flow)

Intra-renal (e.g. acute tubular necrosis)

Post-renal (obstruction)

18
Q

T/F

ARF is usually reversible

A

True

19
Q

T/F

CRF is usually reversible

A

False

20
Q

Name 3 causes of Chronic Renal Failure (CRF)

A

Diabetes
Hypertension
Glomerulonephritis

21
Q

What are the 2 treatment options for End Stage Renal Disease?

A

Dialysis

Transplant

22
Q

How does Hemodialysis differ from Peritoneal dialysis?

A

Hemodialysis: Blood pumped into machine across membrane

Peritoneal dialysis: fluid exchanged through peritoneum

23
Q

In Hemodialysis, what 3 things usually diffuse out of blood?

What diffuses in?

A

Water, Creatinine, Potassium

Bicarb

24
Q

How often is Hemodialysis administered?

What drug must be taken?

A

3-4 times/week
3-4 hours each session

Blood thinners

25
Q

How often is fluid exchanged in CAPD (chronic ambulatory peritoneal dialysis)?

What is a major risk?

A

4-6 times/day

Infection

26
Q

Is body fluid homeostasis maintained with hemodialysis?

A

No

27
Q

What occurs between hemodialysis sessions?

2 limitations

A

Body weight increases
(water retention)

Plasma creatinine increases
(synth > output)

28
Q

1 millimolar solution of CaCl2 = _____ mEq Ca+2 and _____ mEq Cl-

A

2

2

29
Q

What 2 factors affect the percentage or TBW (total body water)?

A

Gender

Age

30
Q

What percentage of TBW is intracellular and extracellular?

A

Intracellular - 2/3

Extracellular - 1/3

31
Q

What are the 3 components of the ECF (extracellular fluid) and what is their breakdown?

A

Interstitial fluid - 75%
Plasma - 25%
Transcellular fluid - 5%

32
Q

What makes up transcellular fluid?

A

CSF
Aqueous humor
GI tract secretions
Urine

33
Q

What separates body fluid compartments?

A

Vascular Endothelium

34
Q

Intracellular fluid is high in what cation?
Extracellular fluid is high in what cation?

What sets up this dynamic?

A

Intra - potassium

Extra - sodium

sodium potassium pump

35
Q

What 3 things is ICF high in?

What 3 things is ECF high in?

A

ICF - K+, proteins, organic phosphates

ECF - Na+, Cl-, bicarb

36
Q

What are 2 factors that help set up solute differential between ECF and ICF?

A

ATP-ase Na/K pump

Membrane transporters

37
Q

Why is ECF volume directly related to total NaCl content?

A

Na+ and attendant ions (Cl-/HCO3-) account for 95% ECF osmolarity

38
Q

What is the dilution principle equation?

A

Volume = Amount added / Concentration

39
Q

What are the 4 markers used to measure Extracellular Volume?

A

Radiolabeled sodium
Sucrose
Mannitol
Inulin

40
Q

What are 2 markers used to measure Plasma Volume?

A

Iodinated Albumin

T-1824 (Evans blue)

41
Q

What are 3 markers used to measure Total Body Water?

A

Tritiated water
Heavy water
Antipyrine

42
Q

How does one measure Interstitial Volume?

A

Extracellular fluid volume - Plasma volume

43
Q

How does one measure Intracellular Volume?

A

Total body water - Extracellular Fluid volume

44
Q

Why is it not possible to measure Interstitial or Intracellular volume directly?

A

There is no clinical method for taking a direct interstitial or intracellular fluid sample from a living patient

45
Q

Why is it important to use a single marker if multiple measurements of a specific compartment volume are required?

A

Markers that are used in the same space may give slightly varying values based on composition differences of the marker

46
Q

What happens to RBC in hypotonic solution?

A

Expansion

47
Q

What happens to RBC in hypertonic solution?

A

Shrinkage

48
Q

Why is urea often Hypotonic?

A

Cell membrane is permeable to urea
Reflection coefficient is not zero

(quantitatively might appear isotonic, but remember this is referring to water - if permeable to urea will often be Hypo)

49
Q

Name 4 ways the intracellular-extracellular fluid volume can be disrupted.

A

Water ingestion
dehydration
infusions
fluid loss

50
Q

Fluid exchange between the interstitium and the intracellular space is driven primarily by…

A

Osmotic Pressure

*water movement only

51
Q

What are the 2 major renal zones?

A

Outer Cortex

Inner Medulla

52
Q

What is the relationship between the renal tissue and the renal calyces and pelvis?

A

Distal proximal tubules of nephrons transfer filtrate to medullary collecting ducts that converge at inner edge of medulla forming calyces

53
Q

What are the 4 principal segments of the Nephron?

A

Proximal tubule
Loop of Henle
Distal tubule
Collecting tubule

54
Q

What are the 2 types of nephrons?

Where are the glomeruli located?

A

Cortical (short looped)
glomerulus close to surface

Juxtamedullary (long looped)
glomerulus at cortex/medulla junction

55
Q

In the Cortical (short looped) nephron, where are the following located:

Proximal and distal tubule

Loop of Henle

Collecting tubule

A

Cortex

Cortex and Outer Medulla

Cortex, Outer medulla, Inner medulla

56
Q

In the Juxtamedullary nephron, where are the following located:

Proximal and distal tubule

Loop of Henle

Collecting tubule

A

Cortex

Cortex, Outer and Inner Medulla

Cortex, Outer and Inner Medulla

57
Q

What is the anatomical difference between the Cortical and Juxtamedullary Nephrons?

A

Juxtamedullary has

Loop of Henle in Inner Medulla

*cortical nephrons only go as far as outer medulla

58
Q

What are the proportions of Cortical and Juxtamedullary Nephrons?

A

Cortical - 80%

Juxtamedullary - 20%

59
Q

Juxtamedullary Nephrons appear to have a cross species function of what?

A

Concentrating Urine

60
Q

In what way is the vascular arrangement surrounding the glomerulus unique?

What is the pathway?
(4 things)

A

2 sets of Arterioles

afferent arteriole > glomerular capillaries > efferent arteriole > peritubular capillaries

61
Q

What do 2 sets of Arterioles do in the glomerulus?

A

Help regulate Glomerular Filtration

*upstream and downstream regulation of glomerular capillaries

62
Q

What is the function of peritubular capillaries?

A

Reabsorption

  • travel alongside length of nephron
  • *Vasa Recta in Loop of Henle
63
Q

What is the Vasa Recta?

A

Subset of Peritubular capillaries running alongside Loop of Henle

64
Q

From what are the Vasa Recta derived?

A

Efferent arterioles of Juxtamedullary Nephrons

65
Q

What percentage of cardiac output is delivered to the kidney?

A

25%

66
Q

How does Renal Oxygen consumption compare with other organs?

A

Very high

67
Q

Why is artery-vein Oxygen concentration analysis in the kidney deceptive when ascertaining consumption?

A

Oxygen concentration difference low

BUT,

Blood flow is so high, Kidney Oxygen consumption also very high

68
Q

How is Renal Oxygen consumption calculated?

equation

A

Oxygen consumption = a-v Oxygen difference x Blood Flow

69
Q

Describe Phase 1 of Renal Blood flow and Oxygen consumption

A

Above 150, proportional

*no change in a-v Oxygen difference

70
Q

Describe Phase 2 of Renal blood flow to Oxygen consumption

A

150-75, kidney works harder to extract oxygen

*a-v Oxygen difference increases

71
Q

Describe Phase 3 of Renal blood flow to Oxygen consumption

A

Below 75, a-v difference maximal

*Renal Ischemia

72
Q

What are the 3 principal elements of Renal Function?

A

Glomerular Filtration
Tubular Reabsorption
Tubular Secretion

73
Q

What is the Filtration Fraction?

A

20%

*plasma entering glomerular capillaries filtered into Bowman’s Space

74
Q

What is the Filtered Load?

A

Concentration of Solutes in glomerular capillary

75
Q

How does Tubular Secretion maintain homeostasis?

What is it making up for?

A

Glomerulus doesn’t filter large, charged molecules.

glomerulus selective

76
Q

Are conclusions drawn from urine concentration alone?

What must you know?

A

No.

Must know Urine Flow Rate

77
Q

How does Urine move to the Bladder?

A

Calices initiate Peristaltic Contraction via inherent pacemaker activity

78
Q

What is the Micturition Reflex?

What contracts and relaxes?

A

Parasympathetic response as bladder fills

Detrusor contracts
Bladder neck relaxes

79
Q

What is the Voluntary component of the Micturition Reflex?

A

External Urethral Sphincter

*internal by bladder is involuntary

80
Q

Name 2 Micturition abnormalities

A

Automatic bladder
(spinal cord damage of voluntary supression)

Atonic bladder
(loss of sensory nerves = no reflex, leads to overflow incontinence)
81
Q

What are the principal structural components of the Glomerular filtration barrier?
(3 things)

A

Fenestrated Endothelium
Basement membrane
Epithelium (podocytes)

82
Q

5 functions of Mesangial cells:

A
Structural support for capillaries
Secrete ECM
Phagocytosis
Secrete Prostaglandins/cytokines
Contractile
83
Q

What 2 main factors determine filterability?

A

Size

Charge

84
Q

T/F

For “freely filtered” substances, the concentration of solutes in Bowman’s space will be = plasma.

A

True

85
Q

What results in high protein plasma concentration immediately downstream of the Glomerulus?

A

Proteins aren’t filtered across glomerulus

86
Q

T/F

Bowman’s glomerulus has no Oncotic Pressure

A

True

87
Q

T/F

Oncotic Pressure increases from Afferent to Efferent arteriole.

A

True

88
Q

What is often seen in Glomerular Disease?

A

Proteinuria

89
Q

Name 4 consequences to Proteinuria do to Glomerular Disease.

A

Thrombosis
Infection
Hyperlipidemia
Edema

90
Q

What are the main forces in the Glomerular capillary?

2 types?

A

Starling Forces

Hydrostatic and Oncotic

91
Q

What is the difference between osmotic and oncotic pressure?

A

Oncotic due to Protein

92
Q

What is the term for the Filtration coefficient?

How is it determined?

A

Kf

ability of capillaries to allow passage of water

93
Q
T/F
Glomerular filtration (Kf) is much higher than in systemic capillaries
A

True

94
Q

What causes Generalized Edema?

A

Na+ retention

*expands entire ECF volume

95
Q

What are 3 causes of Localized Edema?

A
Venous obstruction (increase Pc)
Inflammation (increase Pc and Kf)
Lymphatic obstruction (increases Pi-c)

*protein not returned to systemic circulation in lymphatic obstruction

96
Q

Why does Glomerular capillary Hydrostatic pressure remain relatively constant?

A

Afferent and Efferent resistance points at arterioles

97
Q

Why does oncotic pressure increase along the glomerular capillary?

A

Protein not filtered into glomerulus

98
Q

When does the Net Filtration Pressure = 0?

A

When Oncotic Pressure in the glomerular capillary increases to the point it = Hydrostatic Pressure

99
Q

Filtration Pressure Equilibrium and Disequilibrium?

A

???

100
Q

Why is Hydrostatic pressure so low by the time the blood reaches the Peritubular capillaries?

A

It has passed 2 resistance points

*before and after Bowman’s Capsule

101
Q

What is the Ultrafiltration coefficient?

A

Filtration coefficient of a semipermeable membrane

102
Q

How does the Glomerular Ultrafiltration coefficient compare to systemic Ultrafiltration?

A

Much higher in Glomerulus

103
Q

How many times/day is the entire plasma volume filtered by the kidneys?

A

60

104
Q

T/F

Everything increases/decreases with Afferent arteriole increase/decrease in pressure

A

True

*Hydrostatic Pressure, Glomerular Filtration Rate, and Renal Plasma Flow

105
Q

T/F
Hydrostatic Pressure, Glomerular Filtration, and Renal Plasma flow all increase/decrease with increase/decrease of Efferent arteriole pressure.

A

False

*Inverse on Renal Plasma Flow

106
Q

What primarily regulates Glomerular Filtration?

A

Afferent Arteriole

107
Q

What two factors constrict the Afferent Arteriole?

A

Sympathetic nerves

Angiotensin II
affects both afferent and efferent

108
Q

What do Prostaglandins do to regulate glomerular filtration?

What are 2 examples of such prostaglandins?

A

Vasodilate

PGE2 and PGI2

109
Q

T/F
Angiotensin II, along with constricting the glomerular arterioles, also causes production of PGE2 and PGI2, which constricts said arterioles.

A

True

110
Q

What can NSAID’s + Sympathetic nerve activity lead to?

A

Acute Renal failure

  • no vasodilation occurring
  • *runaway vasoconstriction of kidney
111
Q

What does an increase in Afferent vasoconstriction due to Renal Sympathetic Activity and Angiotensin II cause?

A

“Pre-renal” acute renal failure

112
Q

What are 3 main factors that adversely affect the GFR?

A

Kf (ultrafiltration coefficient) change
(glomerular disease or mesangial cell contractility)

Oncotic pressure change

Intratubular pressure change (obstruction)

113
Q

What does Mesangial cell contractility affect?

A

Capillary surface area

114
Q

How does complete Uretal obstruction stop GFR completely?

A

Damages glomeruli through pressure build-up

115
Q

What is the Uretorenal reflex?

A

Sympathetic reflex constricting arterioles due to Uretal Obstruction

116
Q

Why doesn’t the GFR constantly change with normal fluctuations of pressure?

A

Autoregulatory nature of kidney

  • maintains GFR over wide range of pressures
  • *70 and above
117
Q

Why do we know Autoregulation of kidney is intrinsic?

A

Transplanted kidneys

Perfused isolated kidneys (in vitro, no hormones)

118
Q

T/F
Resistance changes in the Afferent Arteriole cause changes in the Glomerular Filtration Rate and the Renal Perfusion Rate

A

True

*this is why we know Afferent Arteriole is control point

119
Q

T/F

Autoregulation prevents changes in GFR and RPF and prevents large changes in water and solute excretion

A

True

120
Q

Reflex resistance changes in the Afferent Arteriole is the _______ theory of Autoregulation.

A

Myogenic

121
Q

T/F

Under the Myogenic theory, an increase in BP would decrease the radius of the Afferent arteriole.

A

True

122
Q

A change in the flow rate/composition of tubular fluid sensed at the Macula Densa is the _____ theory of Autoregulation

A

Tubuloglomerular feedback theory

123
Q

An increase in BP causing an increase of flow rate causes the Macula densa to decrease Afferent Arteriole diameter according to the tubuloglomerular feedback theory of autoregulation.

A

True

124
Q

What is the Macula Densa?

A

Specialized cells at border of Distal Convoluted Tubule

*close proximity to the Afferent arteriole

125
Q

What can override the Autoregulatory system in the Kidney?

Under what circumstances is this a good thing?

A

Sympathetic system

Trauma
don’t want vasodilation to occur with massive blood loss

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