Renal Q1 Flashcards
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
How often is fluid exchanged in CAPD (chronic ambulatory peritoneal dialysis)?
What is a major risk?
4-6 times/day
Infection
26
Is body fluid homeostasis maintained with hemodialysis?
No
27
What occurs between hemodialysis sessions?
| 2 limitations
Body weight increases
(water retention)
Plasma creatinine increases
(synth > output)
28
1 millimolar solution of CaCl2 = _____ mEq Ca+2 and _____ mEq Cl-
2
| 2
29
What 2 factors affect the percentage or TBW (total body water)?
Gender
| Age
30
What percentage of TBW is intracellular and extracellular?
Intracellular - 2/3
| Extracellular - 1/3
31
What are the 3 components of the ECF (extracellular fluid) and what is their breakdown?
Interstitial fluid - 75%
Plasma - 25%
Transcellular fluid - 5%
32
What makes up transcellular fluid?
CSF
Aqueous humor
GI tract secretions
Urine
33
What separates body fluid compartments?
Vascular Endothelium
34
Intracellular fluid is high in what cation?
Extracellular fluid is high in what cation?
What sets up this dynamic?
Intra - potassium
Extra - sodium
sodium potassium pump
35
What 3 things is ICF high in?
What 3 things is ECF high in?
ICF - K+, proteins, organic phosphates
ECF - Na+, Cl-, bicarb
36
What are 2 factors that help set up solute differential between ECF and ICF?
ATP-ase Na/K pump
| Membrane transporters
37
Why is ECF volume directly related to total NaCl content?
Na+ and attendant ions (Cl-/HCO3-) account for 95% ECF osmolarity
38
What is the dilution principle equation?
Volume = Amount added / Concentration
39
What are the 4 markers used to measure Extracellular Volume?
Radiolabeled sodium
Sucrose
Mannitol
Inulin
40
What are 2 markers used to measure Plasma Volume?
Iodinated Albumin
| T-1824 (Evans blue)
41
What are 3 markers used to measure Total Body Water?
Tritiated water
Heavy water
Antipyrine
42
How does one measure Interstitial Volume?
Extracellular fluid volume - Plasma volume
43
How does one measure Intracellular Volume?
Total body water - Extracellular Fluid volume
44
Why is it not possible to measure Interstitial or Intracellular volume directly?
There is no clinical method for taking a direct interstitial or intracellular fluid sample from a living patient
45
Why is it important to use a single marker if multiple measurements of a specific compartment volume are required?
Markers that are used in the same space may give slightly varying values based on composition differences of the marker
46
What happens to RBC in hypotonic solution?
Expansion
47
What happens to RBC in hypertonic solution?
Shrinkage
48
Why is urea often Hypotonic?
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
Name 4 ways the intracellular-extracellular fluid volume can be disrupted.
Water ingestion
dehydration
infusions
fluid loss
50
Fluid exchange between the interstitium and the intracellular space is driven primarily by...
Osmotic Pressure
*water movement only
51
What are the 2 major renal zones?
Outer Cortex
| Inner Medulla
52
What is the relationship between the renal tissue and the renal calyces and pelvis?
Distal proximal tubules of nephrons transfer filtrate to medullary collecting ducts that converge at inner edge of medulla forming calyces
53
What are the 4 principal segments of the Nephron?
Proximal tubule
Loop of Henle
Distal tubule
Collecting tubule
54
What are the 2 types of nephrons?
Where are the glomeruli located?
Cortical (short looped)
glomerulus close to surface
Juxtamedullary (long looped)
glomerulus at cortex/medulla junction
55
In the Cortical (short looped) nephron, where are the following located:
Proximal and distal tubule
Loop of Henle
Collecting tubule
Cortex
Cortex and Outer Medulla
Cortex, Outer medulla, Inner medulla
56
In the Juxtamedullary nephron, where are the following located:
Proximal and distal tubule
Loop of Henle
Collecting tubule
Cortex
Cortex, Outer and Inner Medulla
Cortex, Outer and Inner Medulla
57
What is the anatomical difference between the Cortical and Juxtamedullary Nephrons?
Juxtamedullary has
Loop of Henle in Inner Medulla
*cortical nephrons only go as far as outer medulla
58
What are the proportions of Cortical and Juxtamedullary Nephrons?
Cortical - 80%
Juxtamedullary - 20%
59
Juxtamedullary Nephrons appear to have a cross species function of what?
Concentrating Urine
60
In what way is the vascular arrangement surrounding the glomerulus unique?
What is the pathway?
(4 things)
2 sets of Arterioles
afferent arteriole > glomerular capillaries > efferent arteriole > peritubular capillaries
61
What do 2 sets of Arterioles do in the glomerulus?
Help regulate Glomerular Filtration
*upstream and downstream regulation of glomerular capillaries
62
What is the function of peritubular capillaries?
Reabsorption
* travel alongside length of nephron
* *Vasa Recta in Loop of Henle
63
What is the Vasa Recta?
Subset of Peritubular capillaries running alongside Loop of Henle
64
From what are the Vasa Recta derived?
Efferent arterioles of Juxtamedullary Nephrons
65
What percentage of cardiac output is delivered to the kidney?
25%
66
How does Renal Oxygen consumption compare with other organs?
Very high
67
Why is artery-vein Oxygen concentration analysis in the kidney deceptive when ascertaining consumption?
Oxygen concentration difference low
BUT,
Blood flow is so high, Kidney Oxygen consumption also very high
68
How is Renal Oxygen consumption calculated?
| equation
Oxygen consumption = a-v Oxygen difference x Blood Flow
69
Describe Phase 1 of Renal Blood flow and Oxygen consumption
Above 150, proportional
*no change in a-v Oxygen difference
70
Describe Phase 2 of Renal blood flow to Oxygen consumption
150-75, kidney works harder to extract oxygen
*a-v Oxygen difference increases
71
Describe Phase 3 of Renal blood flow to Oxygen consumption
Below 75, a-v difference maximal
*Renal Ischemia
72
What are the 3 principal elements of Renal Function?
Glomerular Filtration
Tubular Reabsorption
Tubular Secretion
73
What is the Filtration Fraction?
20%
*plasma entering glomerular capillaries filtered into Bowman's Space
74
What is the Filtered Load?
Concentration of Solutes in glomerular capillary
75
How does Tubular Secretion maintain homeostasis?
| What is it making up for?
Glomerulus doesn't filter large, charged molecules.
| glomerulus selective
76
Are conclusions drawn from urine concentration alone?
What must you know?
No.
Must know Urine Flow Rate
77
How does Urine move to the Bladder?
Calices initiate Peristaltic Contraction via inherent pacemaker activity
78
What is the Micturition Reflex?
What contracts and relaxes?
Parasympathetic response as bladder fills
Detrusor contracts
Bladder neck relaxes
79
What is the Voluntary component of the Micturition Reflex?
External Urethral Sphincter
*internal by bladder is involuntary
80
Name 2 Micturition abnormalities
Automatic bladder
(spinal cord damage of voluntary supression)
```
Atonic bladder
(loss of sensory nerves = no reflex, leads to overflow incontinence)
```
81
What are the principal structural components of the Glomerular filtration barrier?
(3 things)
Fenestrated Endothelium
Basement membrane
Epithelium (podocytes)
82
5 functions of Mesangial cells:
```
Structural support for capillaries
Secrete ECM
Phagocytosis
Secrete Prostaglandins/cytokines
Contractile
```
83
What 2 main factors determine filterability?
Size
| Charge
84
T/F
| For "freely filtered" substances, the concentration of solutes in Bowman's space will be = plasma.
True
85
What results in high protein plasma concentration immediately downstream of the Glomerulus?
Proteins aren't filtered across glomerulus
86
T/F
| Bowman's glomerulus has no Oncotic Pressure
True
87
T/F
| Oncotic Pressure increases from Afferent to Efferent arteriole.
True
88
What is often seen in Glomerular Disease?
Proteinuria
89
Name 4 consequences to Proteinuria do to Glomerular Disease.
Thrombosis
Infection
Hyperlipidemia
Edema
90
What are the main forces in the Glomerular capillary?
2 types?
Starling Forces
Hydrostatic and Oncotic
91
What is the difference between osmotic and oncotic pressure?
Oncotic due to Protein
92
What is the term for the Filtration coefficient?
How is it determined?
Kf
ability of capillaries to allow passage of water
93
```
T/F
Glomerular filtration (Kf) is much higher than in systemic capillaries
```
True
94
What causes Generalized Edema?
Na+ retention
*expands entire ECF volume
95
What are 3 causes of Localized Edema?
```
Venous obstruction (increase Pc)
Inflammation (increase Pc and Kf)
Lymphatic obstruction (increases Pi-c)
```
*protein not returned to systemic circulation in lymphatic obstruction
96
Why does Glomerular capillary Hydrostatic pressure remain relatively constant?
Afferent and Efferent resistance points at arterioles
97
Why does oncotic pressure increase along the glomerular capillary?
Protein not filtered into glomerulus
98
When does the Net Filtration Pressure = 0?
When Oncotic Pressure in the glomerular capillary increases to the point it = Hydrostatic Pressure
99
Filtration Pressure Equilibrium and Disequilibrium?
???
100
Why is Hydrostatic pressure so low by the time the blood reaches the Peritubular capillaries?
It has passed 2 resistance points
*before and after Bowman's Capsule
101
What is the Ultrafiltration coefficient?
Filtration coefficient of a semipermeable membrane
102
How does the Glomerular Ultrafiltration coefficient compare to systemic Ultrafiltration?
Much higher in Glomerulus
103
How many times/day is the entire plasma volume filtered by the kidneys?
60
104
T/F
| Everything increases/decreases with Afferent arteriole increase/decrease in pressure
True
*Hydrostatic Pressure, Glomerular Filtration Rate, and Renal Plasma Flow
105
T/F
Hydrostatic Pressure, Glomerular Filtration, and Renal Plasma flow all increase/decrease with increase/decrease of Efferent arteriole pressure.
False
*Inverse on Renal Plasma Flow
106
What primarily regulates Glomerular Filtration?
Afferent Arteriole
107
What two factors constrict the Afferent Arteriole?
Sympathetic nerves
| Angiotensin II
affects both afferent and efferent
108
What do Prostaglandins do to regulate glomerular filtration?
What are 2 examples of such prostaglandins?
Vasodilate
PGE2 and PGI2
109
T/F
Angiotensin II, along with constricting the glomerular arterioles, also causes production of PGE2 and PGI2, which constricts said arterioles.
True
110
What can NSAID's + Sympathetic nerve activity lead to?
Acute Renal failure
* no vasodilation occurring
* *runaway vasoconstriction of kidney
111
What does an increase in Afferent vasoconstriction due to Renal Sympathetic Activity and Angiotensin II cause?
"Pre-renal" acute renal failure
112
What are 3 main factors that adversely affect the GFR?
Kf (ultrafiltration coefficient) change
(glomerular disease or mesangial cell contractility)
Oncotic pressure change
Intratubular pressure change (obstruction)
113
What does Mesangial cell contractility affect?
Capillary surface area
114
How does complete Uretal obstruction stop GFR completely?
Damages glomeruli through pressure build-up
115
What is the Uretorenal reflex?
Sympathetic reflex constricting arterioles due to Uretal Obstruction
116
Why doesn't the GFR constantly change with normal fluctuations of pressure?
Autoregulatory nature of kidney
* maintains GFR over wide range of pressures
* *70 and above
117
Why do we know Autoregulation of kidney is intrinsic?
Transplanted kidneys
| Perfused isolated kidneys (in vitro, no hormones)
118
T/F
Resistance changes in the Afferent Arteriole cause changes in the Glomerular Filtration Rate and the Renal Perfusion Rate
True
*this is why we know Afferent Arteriole is control point
119
T/F
| Autoregulation prevents changes in GFR and RPF and prevents large changes in water and solute excretion
True
120
Reflex resistance changes in the Afferent Arteriole is the _______ theory of Autoregulation.
Myogenic
121
T/F
| Under the Myogenic theory, an increase in BP would decrease the radius of the Afferent arteriole.
True
122
A change in the flow rate/composition of tubular fluid sensed at the Macula Densa is the _____ theory of Autoregulation
Tubuloglomerular feedback theory
123
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.
True
124
What is the Macula Densa?
Specialized cells at border of Distal Convoluted Tubule
*close proximity to the Afferent arteriole
125
What can override the Autoregulatory system in the Kidney?
Under what circumstances is this a good thing?
Sympathetic system
| Trauma
don't want vasodilation to occur with massive blood loss
