E1- Random Flashcards
(95 cards)
1
Q
What type of cells secrete renin?
A
Granular/Juxtaglomerular cells
2
Q
What type of cells contract in response to AT II?
A
Mesangial cells
3
Q
What are the two main barrier to proteins?
A
Basal lamina and filtration slits
4
Q
What is the effect of NSAIDs?
A
Inhibit synthesis of prostaglandins so there is no vasodilation to oppose alpha 1 (loss of protective affect on RBF)
5
Q
What 5 types of transports occur in the PT?
A
Primary active Na+, K+ pump Secondary active Na+, glucose, AA symport Tertiary active alpha-KG, PAH OAT Na+, H+ antiport Cl- paracellular transport
6
Q
What hormone increases the activity of the Na+, H+ transporter?
A
AT II
7
Q
In what part of the nephron does Mannitol work? (osmotic diuretic)
A
Proximal tubule
8
Q
How does Mannitol work? (osmotic diuretic)
A
Blocks the reabsorption of H20, trapping it in the nephron lumen to then be excreted with Na+
9
Q
What is the thin descending limb permeable to?
A
H20
10
Q
What is the thick ascending limb permeable to?
A
NaCl
11
Q
What is pattern of flow in the descending vasa recta?
A
H2O flows out
NaCl flows in
12
Q
What is pattern of flow in the ascending vasa recta?
A
H2O flows in
NaCl flows out
13
Q
What types of transports are in the LOH? (3)
A
Primary active Na+, K+ pump
NKCC2 transporter
Back flow of K+ –> paracellular Ca2+ reabsorption
14
Q
In what part of the nephron does Furosemide work? (loop diuretic)
A
LOH
15
Q
How does Furosemide work? (loop diuretic)
A
Inhibits the NKCC2 transporter and Ca2+ reabsorption
16
Q
What hormone increases the activity of the NKCC2 transporter?
A
ADH/vasopressin
17
Q
Is the early distal tubule permeable to H2O?
A
No
18
Q
What determines the permeability of the late distal tubule and collecting duct to H2O?
A
ADH/vasopressin
19
Q
What portion of the nephron is considered the diluting segment?
A
Early distal tubule
20
Q
What type of transporter is in the early distal tubule?
A
NCC symport (Na+, Cl-)
21
Q
In what part of the nephron does Chlorothiazide work? (thiazide diuretic)
A
Early distal tubule
22
Q
How does Chlorothiazide work? (thiazide diuretic)
A
Inhibits the NCC symporter
Increases Calcium reabsorption in the distal tubule
23
Q
What types of transporter are in the late distal tubule? (5)
A
Primary active Na+, K+ pump ENaC antiport H+ uniport H+, K+ pump Ca2+, Na+ pump
24
Q
What hormone increases the activity of the Na+, K+ pump?
A
Aldosterone
25
What hormone increases the activity of the ENaC transporter?
Aldosterone
26
What hormone increases the activity of the H+ uniport?
Aldosterone
27
In what part of the nephron do Amiloride and Spironolactone work? (K+-sparing diuretics)
Collecting ducts
28
How do Amiloride and Spironolactone work? (K+-sparing diuretics)
Amiloride- Inhibits the ENaC antiport
| Spiromolactone- Inhibits aldosterone
29
What part of the tubule adjusts the final concentration of urine?
Collecting duct
30
What porin inserts into the nephron cell when ADH levels are high to allow for the passage of H2O?
AQP2
31
What porins are always present that allow water to be reabsorbed?
AQP3
| AQP4
32
What is the driving force for filtration?
P(GC)
33
If total urine flow is greater than 1100, is the subject in a positive or negative water balance?
negative
34
If total urine flow is less than 1100, is the subject in a positive or negative water balance?
positive
35
How are nephrons arranged?
In parallel
36
What two capillary beds are arranged in parallel?
Glomerular
| Peritubular (cortical, vasa recta)
37
What autoregulation mechanism responds to changes in BP?
Myogenic
38
What autoregulation mechanism responds to changes in salt load?
Tubuloglomerular feedback
39
What are the characteristics of the perfect GFR marker>
Freely filtered, but neither reabsorbed nor secreted
40
What two things can be used to measure GFR?
Inulin clearance and creatine clearance
41
What can be used to measure RPF?
PAH
42
If the clearance of a substance is greater than the clearance of creatine, thus greater than GFR, was the substance secreted or reabsorbed?
Secreted
43
If the clearance of a substance is less than the clearance of creatine, thus less than GFR, was the substance secreted or reabsorbed?
Reabsorbed
44
If the clearance ratio of a substance to the clearance of inulin is zero, then what must also be true?
The substance must also be a GFR marker
45
If the clearance ratio of a substance to the clearance of inulin is less than 1.0, then what must also be true?
The substance is not filtered, or is filtered and reabsorbed
46
If the clearance ratio of a substance to the clearance of inulin is more than 1.0, then what must also be true?
The substance is filtered and secreted
47
What does it mean if the transport rate is positive?
Some material was removed from the filtrate by reabsorption
48
What does it mean if the transport rate is negative?
Some material was added to the filtrate by secretion
49
What does it mean if the tubular fluid to plasma ratio equals zero?
The substance has been exactly proportional to the reabsorption of water
50
What does it mean if the tubular fluid to plasma ratio is less than 1?
The reabsorption of the substance has occurred to a greater extent than water
51
What does it mean if the tubular fluid to plasma ratio is greater than 1?
The reabsorption of the substance has occurred to a lesser extent than water OR there has been a net secretion of the substance
52
If you increase GFR, will the /Tm be reached at higher or lower plasma concentrations?
Lower
53
What can cause hyperosmotic volume contraction?
Very low levels of ADH
Ineffective ADH
(dehydration, DM insipidus)
54
Is plasma osmolality high/low in hyperosmotic volume contraction?
Is urine osmolality high/low in hyperosmotic volume contraction?
```
Plasma = high
Urine = low
```
55
What is the cause of low ADH in neurogenic diabetes insipidus?
Hypothalamic-pituitary injury
| will respond to exogenous ADH agonist- desmopressin
56
What is the cause of low ADH in nephrogenic diabetes insipidus?
Renal origin, kidney is unable to respond to ADH or desmopressin
Plasma ADH is high since Hypothalamic-pituitary are functioning normally
57
What can cause hyposmotic volume expansion?
SIADH
| Acute water load
58
What electrolyte imbalance is seen with SIADH?
Hyponatremia (euvolemia)
59
Is K+ higher inside/outside the cell?
| Is Na+ higher inside/outside the cell?
```
K+ = inside
Na+ = outside
```
60
Alpha1 activation has what effect on K+?
Shift of K+ out of cells
| Hyperkalemia
61
Beta2 activation has what effect on K+?
Shift of K+ into cells
| Hypokalemia
62
Insulin activation has what effect on K+?
Dietary shift of K+ into cells after a meal
| Hypokalemia
63
Aldosterone activation has what effect on K+?
Shift of K+ into tubule cells for excretion
| Hypokalemia
64
Besides alpha1 activation, what else can cause a K+ shift out of cells?
Hyperosmolarity and exercise
65
What is is effect of a hyperkalemic state on pH?
Acidosis
| Hyperkalemic state, K+ moves into the cells, this stimulates the movement of H+ out of the cells
66
What is is effect of a hypokalemic state on pH?
Alkalosis
| Hypokalemic state, K+ moves into the cells, this stimulates the movement of H+ out of the cells
67
What is an example of a volatile acid?
Respiratory CO2
68
What is the fist line of defense against pH change?
Buffers
69
What determines the effectiveness of a buffer?
Concentration
| pK (most effective within +/- one unit
70
What is the most important buffering system in the ECF.
Bicarbonate
71
What is normal ratio of HCO3- to dissolved CO2?
20:1
72
What causes metabolic disturbances?
Changes in HCO3-
73
What causes respiratory disturbances?
Changes in CO2 (must be compensated for by kidneys)
74
What are causes of Metabolic acidosis?
```
Ingestion of acid
Formation of non-volatile acids (lactic acids)
Diabetic ketoacidosis
Loss of HCO3- (diarrhea)
Renal HCO3- recovery reduced
Excretion of NH4+ reduced
```
75
What are causes of Metabolic alkalosis?
Antacid abuse
ECF volume contraction (vomiting, diuretics)
Hyperaldosteronism
76
What can cause of Respiratory alkalosis?
Hyperventilation
- high altitude
- anxiety
- hypoxemia
77
What can cause of Respiratory acidosis?
COPD
Asthma
Airway obstruction
78
What is the Mass Action Rule?
Every 10 increase in CO2 results in a 1 increase in HCO3-
| Every 10 decrease in CO2 results in a 2 decrease in HCO3-
79
What parts of the nephron do not change transport on the face of increased or decreased total body K+?
PT and LOH
80
Why is metabolic alkalosis maintained even when vomiting has stopped?
ECF volume contraction increases H+ loss via RAAS
| critical factor is elevated aldosterone
81
What is the treatment of metabolic alkalosis?
Saline
| Corrects fluid volume deficit and then adjusts RAAS, leading to the excretion of HCO3-
82
Why will saline not work to treat metabolic alkalosis caused by aldosterone excess? (Conn syndrome)
What is the appropriate treatment?
ECF volume is already expanded
| Remove tumor or aldosterone antagonist- Spirolactone
83
What type of acidoses have a normal anion gap?
Simple HCO3- loss: Diarrhea or Renal Tubular Acidosis
| Cl- increases to meet the drop in HCO3-
84
What type of acidoses have an increased anion gap?
Excess of non-volatile acids
(fixed acids liberate H+ which is buffered by HCO3- w/o changing the Cl- levels)
```
Lactic acidosis
Ketoacidosis
Renal failure- phosphoric sulphuric
Salicylate poisoning- aspirin
Ethylene glycol poisoning
Methanol poisoning
```
85
What type of RTA is due to impaired H+ secretion by H+-ATPase in the distal nephron?
Type 1 (distal)
86
What are the characteristics of Type I (distal) RTA?
Hyperkalemia/Hypokalemia
Normal anion gap/Increased anion gap
Hypokalemia
| Normal anion gap
87
What type of RTA is due to a defect in the Na+-H+ exchanger in the proximal tubule, leading to the imparement of H+ secretion and HCO3- reabsorption?
Type II (proximal)
88
What are the characteristics of Type II (proximal) RTA?
Gain or loss of HCO3-
Normal anion gap/Increased anion gap
Loss of HCO3-
Normal anion gap
(in severe cases may also lead to hypokalemia)
89
What type of RTA is due to a defect in urinary acidification due to inhibition of renal glutaminase, which impairs formation of NH4+?
Type IV
90
What are the characteristics of Type IV RTA?
Hyperkalemia/Hypokalemia
Gain or loss of HCO3-
Normal anion gap/Increased anion gap
Hyperkalemia
Impaired HCO3- generation
Normal anion gap
91
What RTA is associated with a aldosterone deficiency?
Type IV
92
How does diabetic ketoacidosis cause volume depletion?
Ketoacids acidify blood, deplete HCO3-
Plasma glucose increases
Glucose acts as an osmotic diuretic and increases urine flow
93
Would you expect to see hyperkalemia or hypokalemia in a diabetic ketacidosis pt?
Hyperkalemia
94
What hormone will be elevated in a pt with diabetic ketacidosis?
What hormone will be decreased?
Elevated plasma glucose makes the blood hyerposmotic leading to increased ADH
ANP
95
Although vomiting can initiate metabolic alkalosis, what can maintain it?
Volume contraction and hypokalemia
| Volume contraction stimulates aldosterone which increases alkalosis and K+ loss
