Unit 2 Flashcards
(276 cards)
1
Q
Cells of the body depend on..
A
A constant interstitial fluid concentration of solutes and osmolarity
-this is regulated by controlling the amount of extracellular water there is
2
Q
Osmolarity is regulated by…
A
Water intake (thirst)
Renal excretion of water (glomerular filtration and reabsorption)
3
Q
EDF osmolarity is about..
A
300 mOsm/L
4
Q
Kidneys can excrete urine that ranges from..
A
50 mOsm/L - 1200 mOsm/L
5
Q
How can the kidneys eliminate excess water?
How do they conserve water?
A
Can produce copious amounts of dilute urine
Can produce small amounts o concentrated urine
(Both can be done without changing excretion rates of solutes)
6
Q
ADH regulates _____ (and therefore ___) ____ by controlling:
A
Plasma (and therefore interstitial) osmolarity
Water excretion
7
Q
What happens what plasma osmolarity is increased?
A
Post pituitary ADH secretion increases
Then
Distal tubule H2O permeability increases
Then
Water reabsorption increases
8
Q
As urine osmolarity changes, what happens to plasma osmolarity?
A
There is little to no change
9
Q
Proximal tubule’s job in diluting urine
A
Solutes and water are reabsorbed at equal proportions (isosmotic)
10
Q
Absorption of water in the descending loop of henle is due to:
A
a higher concentration of solutes in the renal medulla interstitium
11
Q
The descending loop of henle concentrates what?
A
The tubular fluid (hyperosmotic)
12
Q
In forming a dilute urine, what happens in the ascending loop of henle (thick)?
A
Reabsorption of electrolytes (Na+, K+, Cl) but not water
Dilutes tubular fluid (hyposmotic)
this part of the loop is NOT permeable to water
13
Q
ADH is ____ in distal and collecting tubules when forming dilute urine. This means:
A
Absent
There is no reabsorption of water
14
Q
The renal handling of water changes to form concentrated urine by the presence of:
A
ADH
15
Q
What does ADH do in the distal and collecting tubules to H2O?
How?
A
Increases permeability to H2O
Causes reabsorption of water and a concentrated (hyperosmotic) urine
-since the renal medulla interstitium is hyperosmotic
16
Q
A concentrated urine depends on _____ and:
A
ADH
A hypertonic renal medullary interstitium
17
Q
Review slide 9
A
Slide 9
18
Q
The most concentrated urine can be is:
A
1200 mOsm/L
19
Q
The min amount o metabolic wastes and excess ions that must be eliminated bu the body to maintain homeostasis is about:
A
600 mOsm/day
20
Q
The minimal amount of urine one must form a day is:
A
600/1200 = .05 L/day
21
Q
What causes the renal medulla to become hyperosmotic ?
A
The countercurrent multiplier system
22
Q
6 general steps of the countercurrent multiplier
A
1- the tubule fills with isosmotic fluid, with all transport systems/permeabilities off
2- ascending Limb pumps turned on— Increases osmolarity of the medulla
3- water permeability of the descending limb turned on. Causes equilibrium between the descending limb and the medulla interstitium (interstitium stays hyperosmotic bc the ascending pumps are still on)
4- tubular flow turned on. The hyperosmotic fluid that was in the descending limb moved to the ascending limb
5- the ascending limb still reabsorb solutes further concentrating the medially interstitium
6- the descending limb loses more water by osmosis again
steps 4-6 are repeated to create a max gradient through the interstitium
23
Q
Review slide 15
A
Slide 15
24
Q
What are impermeable to urea?
A
The ascending limb, distal tubule, and cortical collecting duct
25
What is permeable to urea? And what increases this?
Medullary collecting duct
ADH
26
As urine concentrates with ADH, ____ also concentrates, and is therefore (ACTIVELY/PASSIVELY) reabsorbed into the ____ contributing to:
Urea
Passively
Medullary
Medullary hyperosmolarity
27
Urea reabsorbed into the ___ ____ __ is secreted into the:
Therefore, urea:
Medullary collecting duct
Loop of henle
Recirculates increasing its concentration
28
In the presence of ADH, Urea recirculating (INCREASES/DECREASES), helping to maintain:
Increases
Hyperosmolarity of the renal medulla
29
In the absence of ADH, (MORE/LESS) urea is excreted
More
30
How much urea is remaining after passing through the loop of henle?
20%
31
The blood flow through the vasa recta is only enough to satisfy the needs of:
The tissues
32
Vasa recta capillaries Vs other capillaries
They have the same permeability characteristics
33
The “U” shape of the vasa recta creates a ______ ___ that prevents:
Countercurrent exchanger
The medulla from losing its solute concentration
34
Review slide 19
Slide 19
35
What is central diabetes insipidus (DI)?
Failure of the post pituitary to secrete ADH due to head injury, infection or congenital defect
36
DI patients symptoms
May excrete 10-15 liters of urine per day (polyurea)
Excessive thirst (polydipsia)
Plasma osmolarity may be normal to slightly high depending on access to water
37
ADH and nephrogenic diabetes insipidus
ADH secretion is not impaired
Kidneys don’t respond to ADH either
38
Why don’t the kidneys respond to ADH in nephrogenic diabetes insipidus?
The distal and collecting ducts are insensitive to ADH
Or
There is an impaired countercurrent mechanism, therefore the renal medially isn’t hyperosmotic enough to concentrate the urine appropriately
39
Mechanisms primarily used to control ECF osmolarity and sodium concentration
Osmoreceptor- ADH feedback
Cardiovascular- ADH feedback (I.e. blood pressure and volume)
Thirst mechanism
40
Where are the osmoreceptor cells located?
In the ant hypothalamus
41
What happens to osmoreceptor cells when osmolarity increases?
They shrink, then send nerve signals to the supraoptic nucleus
42
What signals the release of ADH?
The supraoptic nucleus (magnocellular cells) fires into the post pituitary signaling the release of ADH (also the paraventricular to some extent)
43
What reverses the high extracellular osmolarity?
ADH
44
What provides negative feedback to water deficit?
Decreased H2O excreted
45
What happens when there is a water deficit?
Extracellular osmolarity increases
ADH secretion (post pituitary) increases
Plasma ADH increases
H2O permeability in distal tubules and collecting ducts increases
H2O reabsorption increases
H2O excreted DECREASES
46
The supraoptic and paraventricular nuclear cells synthesize ____, but is is RELEASED from the:
ADH
Post pituitary gland
47
Decreased arterial pressure and/or blood volume is detected by _____ in the:
Baroreceptor
Aortic arch and carotid sinuses
And in the atria and pulmonary arteries
48
Baroreceptor feedback to the ______ cause:
Hypothalamus
ADH production and secretion
49
What receptors detect osmotic pressure?
Osmoreceptor
50
The cardiovascular feedback is (MORE/LESS) sensitive than the osmoreceptor feedback
Less
51
Review slide 26
Slide 26
52
What are factors that increase ADH secretion?
Increased plasma osmolarity
Decreased BP or volume
Nausea
Nicotine
Morphine
53
What are factors that decrease ADH secretion?
Decreased plasma osmolarity
Increased BP or volume
Alcohol
54
Where is the thirst center located?
In the ant hypothalamus
55
How do thirst receptors work?
Thirst osmoreceptor detect hyperosmolarity the same way as osmoreceptor that stimulate ADH secretion
56
What affects the thirst center directly?
Angiotensin II
57
Short-lived quick relief of thirst, desire to stop drinking is only satisfied by:
Correction of osmotic balance
58
What helps prevent over-drinking?
Why?
GI dissension
It takes 30-60 min for the fluid to be absorbed and distributed in the body
59
What happens as sodium intake increases
Only a small effect on plasma concentration (assuming ADH and thirst mechanisms function normally)
60
When does thirst sensation begin?
When sodium concentration increases by 2 mEq/L
61
Sensible and insensible water losses must be countered by:
Water intake
62
What increases sodium retention
Angiotensin II and aldosterone
63
Sodium retention is balanced by:
Water reabsorption (osmosis)
64
Angiotensin and aldosterone only effect the _____ of sodium in the ECF, but not the _____
Amount
Concentration
65
What is one case in which aldosterone can be involved in altering osmolarity?
Addison’s disease
66
In Addison’s disease, decreased aldosterone causes....
Decreased Na
Decreased H2O
Eventual decreased BP/volume
Increased thirst
Increased H2O but decreased osmolarity
67
What can trigger salt cravings
Decreased extracellular Na concentration
Decreased BP/blood volume
68
In Addison’s disease, pts have severe ____ cravings in an attempt to restore ____
Salt
ECF Na concentration
69
Potassium needs ___ control
Precise
70
Increased K+ leads to:
Cardiac arrhythmias
Arrest
Fibrillation
71
___% of K+ is intracellular
__% in ECF
98%
2%
72
Dietary intake of K+
50-200 mEq/day
73
ECF K+ concentration is regulated by what mechanisms?
Kidney excretion rate
Redistribution of K+ between ECF and intracellular compartments
74
What are factors that shift K+ into cells?
Insulin
Aldosterone
Beta-adrenergic stimulation
Alkalosis
75
What are factors that shift K+ out of cells?
Insulin deficiency (diabetes mellitus)
Aldosterone deficiency (Addison’s disease)
Beta-adrenegic blockade
Acidosis
Cell lysis
Strenuous exercise
Increased extracellular fluid osmolarity
76
K+ excretion is dependent upon:
K+ filtration rate = GFR X [K+]p
K+ reabsorption rate
K+ secretion rate
77
Review slide 39 pic— know what parts of the loop and percentage that is excreted
Slide 19
78
Why is the filtration rate of K+ fairly constant?
GFR and [K+] do not fluctuate much
79
Where is K+ reabsorption steady?
In proximal tubule and ascending loop
80
why are the distal and collecting tubules most important in regards to K+?
They can reabsorb OR secrete depending on the situation
81
What cells secrete K+?
Via what?
Principal cells
Via sodium potassium pump (basolateral) and luminal potassium channel
82
What cells reabsorb K+?
Intercalated cells (type A)
***Type B secretes, but ok to assume that intercalated reabsorb unless otherwise specified as type B!)T
83
Type A intercalated cells reabsorb K+ via:
H+/K+ ATPase on the apical membrane and basal potassium channel
84
Type B intercalated cells secrete K+ via:
H+/K+ ATPase on the basolateral membrane and luminal potassium channel
85
Review slide 41 and principal and intercalated cells’ mechanism
Slide 41
86
Increased extracellular K+ directly stimulates:
NA/K pump
Synthesis of luminal K+ channels
Production of aldosterone
87
Increased aldosterone stimulates:
NA/K pump
Synthesis of luminal K+ channels
88
What are the principal cell stimulators?
Increased extracellular K+
Increased aldosterone
Increased tubular flow rate
89
What happens with there is increased tubular flow rate?
“Flushing effect” moves secreted K+ down the tubule thus maintaining a concentration gradient between the tubule cells and the lumen
90
What happens with K+ intake increase?
Plasma K+ concentration increases
Aldosterone and K+ secretion cortical collecting tubules increase
K+ excretion increases
91
What happens to plasma aldosterone concentration as serum potassium concentration increases?
It gradually increases
92
What increases urinary K+ secretion?
Which has a more potent effect?
Aldosterone and high potassium
Aldosterone
93
Review slide 45 chart
Slide 45
94
In conditions such as increased Na+ intake or volume expansion, there is ______ aldosterone production, and therefore:
Decreased
Decreased K+ secretion
(This would tend to cause K+ retention anytime these conditions occur)
95
What is the solution to decreased K+ secretion
Distal tubule flow rate is increased, which increases K+ secretion to offset the decreased aldosterone/decreased K+ secretion
96
Decreased calcium concentration causes what?
Hyperactive nerves and muscles (hypercalcemic tetany)
97
Increased calcium concentration causes what?
Decreases neuromuscular activity
Causes heart arrhythmia
98
Calcium in blood...
__% free and ionized
___% bound to plasma proteins
___% is calcium phosphate or citrate
50%
40%
10%
99
Free and ionized calcium can effect what?
Cell membrane
100
Acidosis dose what to calcium
Decreases Ca+2 binding to plasma proteins
101
Calcium intake
~1000 mg/day
102
Calcium lost in feces per day
900 mg/day
103
99% of body calcium is where?
In the bones
104
1% of body calcium is where?
-0.1% is where?
ECF
ICF
105
Parathyroid hormones is secreted by ______ glands in response to:
Parathyroid
Low serum Ca+2 concentration
106
Effects of parathyroid hormone
Increased vitamin D activation (causing GI tract calcium reabsorption )
Renal calcium reabsorption
Ca+2 release from bone
107
What is the only calcium that is filtered?
“Free” calcium (50%)
108
Calcium is _____ and not _____.
Reabsorbed
Secreted
109
Renal calcium excretion =
Calcium filtered - calcium reabsorbed
110
65% of calcium reabsorption happens in the:
20-30% in the:
4-9% in the:
Proximal tubule
Loop of henle
Distal tubule and collecting duct
111
Calcium is reabsorbed along with
H2O
112
As calcium is reabsorbed, ___ is secreted
3 Na+
113
Factors that cause decreased calcium excretion
Increased PTH
Decreased ECF volume
Decreased blood pressure
Increased plasma phosphate
Metabolic acidosis
Vitamin D3 (activated vitamin D)
114
What factors cause increased calcium excretion
Decreased PTH
Increased ECF volume
Increased BP
Decreased plasma phosphate
Metabolic alkalosis
115
Maximum phosphate reabsorption rate
01. Mmoles/min
| * Filtration in excess of that spills into the urine*
116
Most people ingest excess phosphate in ____ and _____.
There (IS/IS NOT) usually phosphate in the urine
Meat
Dairy
IS
117
How does PTH effect phosphate levels
Bone reabsorption releases phosphate into the ECF
Decreases transport max for phosphate
118
How much Mg+2 is filtered by the kidneys per day
2000-4000 mg/day
119
What is the filterable component of magnesium
Free serum magnesium (70% of total level)
120
10-20% of Mg is reabsorbed in the _____
70% in the ____
10% in the ___
Proximal convoluted tubule
Loop of henle
Distal convoluted tubule
121
Review slide 54
Slide 54
122
High sodium intake leads to:
Increased ECF
123
Pressure receptors in right atrium and pulmonary blood vessels inhibits _____ which decreases:
SNS
Tubular sodium reabsorption
124
Increased ECF causes:
Increased BP
Leads to pressure natriuresis/diuresis
125
High sodium intake suppresses ______ formation, and therefore _____ production
Angiotensin II
Aldosterone
(Less Na+ retention)
126
Atrial stretch is caused by
High sodium intake
127
In response to atrial stretch, ___ ____ hormone is released. This causes:
Atrial natriuretic hormone
Increased GFR and decreases Na+ reabsorption
128
Almost all enzymes are sensitive to ___ concentration in the body fluid. Therefore, ___ ___ is necessary
H+
Tight regulation
129
H+ concentration in the blood
.00004 mEq/L
130
PH is expressed as:
PH = log 1/[H+]
131
PH of..
Arterial blood:
Venous blood:
7. 4
| 7. 35
132
Normal blood pH
7.4
133
Blood pH > 7.45:
Blood pH < 7.35:
Alkalosis
Acidosis
134
Extremes in the range of pH that doesn’t cause death in a few hours
6.8-8.0
135
What are the 3 pH regulatory systems - how do they work?
Chemical buffers system
- doesn’t remove excess acid or base.. just “ties them up”
Respiratory center
- removal of CO2, and therefore H2CO3
Kidney excretion of acid or base
- Urine pH ranges from 4.5-8.0
136
What are the first lines of defense against fluctuations in pH?
The buffer and respiratory systems
137
Purpose of buffer
Reduces changes in pH with the addition or loss of H+
138
What are the three buffer systems
Bicarbonate buffer system
Phosphate buffer system
Protein buffer system
139
Buff systems in the ICF
Phosphate buffer system
| Protein buffer systems
Hemoglobin buffer system and amino acid buffers
140
Buffer systems in the ECF
Carbonic acid- bicarbonate buffer system
Protein buffer systems
(Amino acid buffers and
Plasma protein buffers)
141
How is bicarbonate formed?
CO2 reacts with water to form carbonic acid (a weak acid)
This slowly dissociates into bicarbonate and water
**this reaction is reversible**
142
What speeds up the bicarbonate reaction?
CO2 and water reaction speed increased with carbonic an hydrate enzyme
143
Where is the carbonic anhydrase enzyme found?
Lungs
RBCs
Kidney tubule epithelium
144
What happens tp the bicarbonate reaction when acids such as HCl- is added?
The reaction shifts to the left
HCO3- is consumed (decreases)
CO2 accumulates (is then removed by ventilation)
145
What happens to the bicarbonate reaction if a base such as NaOH is added?
The OH- from NaOH combines with H2CO3 to form additional HCO3-
A weak base replaces a strong base
More CO2 and H2O react as H2CO3- decrease to make more bicarbonate
Bicarbonate accumulates (then is removed by the kidneys)
146
Phosphate buffer system equation
H2PO4- HPO4-2 + H+
147
In the phosphate buffer system, dihydrogen phosphate dissociates into:
Hydrogen ions and hydrogen phosphate
148
Where is the phosphate buffer system found?
Principally in the kidney tubules where phosphates tend to concentrate
it is also used intracellularly
149
Where does the protein buffer system occur?
Principally intracellularly (ex- hemoglobin)
150
Protein buffer system equation
Hb + H+ HHB
151
Two processes which effect carbon dioxide concentration in the EF
CO2 formed from body metabolism
CO2 lost via pulmonary ventilation
152
Increased respiration causes CO2 and pH relationship how?
Decreases CO2 and H+
Increases pH (more basic)
153
Decreased respiration does what with CO2 and pH?
Increases CO2 and H+
Decreases pH (more acidic)
(Think of CO2 as an acid. You’ll lose acids as you breath)
154
What stimulates respiration ventilation?
[H+]
155
Alterations in ventilation rate change pH by a (LARGE/SMALL) degree.
Therefore:
Small (from 7.2-7.4)
Kidneys still play a dominant role in pH regulation
156
What can lead to respiratory acidosis?
Chronic lung disease (such as emphysema)
157
Excreting an acidic urine reduces:
Excreting a basic urine reduces?
ECF acid
ECF base
158
What is the general mechanism for renal acid-base balance?
HCO3- is continually filtered (and mostly reabsorbed)— removes base
H+ is secreted by the tubules (removing acid)
159
What determines if the turbine will be acidic or basic?
Depends on which is excreted more, bicarbonate or hydrogen ions
If hydrogen secreted more, it will be more basic
If bicarbonate is secreted more, it will be more acidic
160
Bicarbonate reabsorption in the nephron
85% in proximal convoluted tubule
10% in ascending limb
>4.9% in the collecting duct
161
How much bicarbonate is filtered?
How much H+ must be secreted to reabsorb the bicarbonate?
4320 mEq/day
Same
(80 mEq/day of other acids (non-volatile acids) must also be secreted
162
What happens with H+ and bicarb when there is alkalosis
Less H+ is available for secretion
Less bicarb is reabsorbed
163
What happens with H+ and bicarb when there is acidosis
More H+ is available for secretion
More bicarb is reabsorbed (new bicarb can even be produced)
164
What are the three mechanisms for renal acid-base regulation?
Reabsorption of filtered bicarb
Secretion of hydrogen ions
Production of new bicarbonate
(First two tend to be linked)
165
Most acid is generated how?
Internally by metabolism of carbs, fats and protein
Rather than being ingested
166
Volatile acids vs non volatile acid
Volatile can be broken down nicely
Non volatile can only be removed by the kidneys
167
Is carbonic acid volatile or non volatile?
Volatile
168
CO2 removed by ventilation effectively removes:
Acid
169
HCO3- removed by kidneys effectively removes:
Base
170
Examples of non volatile acids
Sulfuric
Phosphoric
Urea
Urate
Oxalate
Acetoacetate
171
Non volatile acids principally removed by kidneys
Titratable acid
Ammonium
172
Ion channels used for bicarb secretion/reabsorption
Na+/K+ pump
Na/H+ exchanger
173
Enzyme needed for bicarb reabsorption
Carbonic anhydrase
174
The proximal tubule has low permeability to ____ in _____ membrane
Bicarbonate
Luminal membrane
175
The proximal tubule has high permeability to:
CO2
176
Bicarbonate production in the tubule is the same as:
Earlier in the nephron
177
Secretion of H+ in the late distal and collecting tubules is by:
Active transport mechanisms (H+ ATPase and H+/K+ ATPase)
178
For every H+ secreted, a bicarbonate is _____.
Reabsorbed
179
Cl-/bicarb exchanger on the basolateral membrane facilitates ___ ___ with the secretion of hydrogen ions..
What does this mechanism do?
Electrical neutrality
It acidified the urine more than earlier parts of the tubule
180
What happens to the excess hydrogen ions after all the bicarbonate is reabsorbed?
They must be buffered by other means— they cannot be secreted in high enough amounts
181
Why can’t excess hydrogen ions be secreted in high amounts?
There is a limit to the amount of free H+ that can be excreted in the urine.
The resp can eliminate volatile acid, but not nonvolatile
182
What is the lowest possible pH in the urine
4.5
183
Phosphate and ammonia buffers are where?
In the kidneys
184
In the phosphate buffer system, H+ is buffered with ____ to form ____. This can form:
Therefore, the reabsorbed bicarbonate inside the tubular cells is:
HPO4-2
H2PO4-
A salt with sodium: NaH2PO4
New
185
Since phosphates are largely reabsorbed in the ___ ____, another buffer system is:
Proximal tubules
Needed later in the nephron
186
The ammonia buffer system combines ammonia with excess ____ ___ to form:
Hydrogen ions
Ammonium (NH4+)
187
The ammonia for the ammonia buffer system comes from the metabolism of _____ in the ____.
This in turn comes from :
Glutamine
Nephron
Liver metabolism of amino acids
188
Precursor of glutamine
It requires what?
Glutamate
ATP and NH+4
189
Review slide 78
Slide 78
190
Ammonia buffer system in the collecting tubule, ___ ___ are actively pumped into the ___ __ where it combines with ___ to form ___
Hydrogen ions
Tubule lumen
Ammonia
Ammonium
191
Ammonia buffer system
In the collecting tubules, the hydrogen ions are generated from ___ ____ as before, and _____ is reabsorbed
Carbonic acid
Bicarbonate
192
Net acid excretion =
NH4+ excretion + urinary titratable acid - bicarbonate excretion
193
Why is NH4+ non-titratable?
Because of its relatively high pK
194
Titratable acid is measured how?
By the emoting of NaOH needed to return pH to 7.4 (includes phosphate buffered acid)
195
Losing an an equivalent of bicarbonate is the same as adding _____ to the ECF
H+
196
PKa =
-log Ka
197
The smaller the the pK, the ____ the acid
Stronger
198
In acidosis, there is a net addition of new ____ in the blood as more ___ and _____ ___ are excreted
Bicarbonate
Ammonium
Titratable acid
199
In alkalosis, ____ __ and ____ excretion decreases to zero, and there is a net loss of _____ in the urine
Titratable acid
Ammonium
Bicarbonate (which is the same as gaining hydrogen ions)
200
Is new bicarbonate produced by the kidneys in alkalosis?
No
You don’t have enough H bc there isn’t enough to get out the bicarb
201
What factors increase H+ secretion and HCO3- absorption?
Increase in..
- PCO2
- H+ (causing decrease in HCO3-)
- Angiotensin II
- aldosterone
Decrease in..
Extracellular fluid volume
Also..
-hypokalemia
202
What causes a decrease in H+ secretion and HCO3- absorption?
Increase in....
Extracellular fluid volume
Decrease in...
- PCO2
- H+ (causing increase in HCO3-)
- angiotensin II
- Aldosterone
Also...
Hyperkalemia
203
CO2 should be though of as (ACID/BASE)
Acid
204
HCO3- increases or decreases are considered a:
Metabolic problem
205
HCO3- should be though of as (ACID/BASE)
Base
206
If the pH decreases because of a fall in HCO3-, then it is a:
Metabolic acidosis
207
If the pH decreases bc of an increase in PCO2, it is a:
Respiratory acidosis
208
Both metabolic and respiratory acidosis cause excess ___ in the renal tubules, which causes a complete reabsorption of _____. Excess H+ is available to bind to _____ and ____ buffers.
H+
HCO3-
Ammonia
Phosphate
(Which also adds to new bicarbonate to the ECF)
209
If pH increases bc of an increase in HCO3-, then it is a :
Metabolic alkalosis
210
If the pH increases bc of a decrease in PCO2, then it is a:
Respiratory alkalosis
211
In both resp and metabolic alkalosis, there is insufficient ____ to reabsorb all the ____, which is subsequently excreted. This is the same as adding ___ to the ___
Acid
Bicarb
Acid
ECF
212
Review slide 86 table
Slide 86
213
Respiratory acidosis is caused by ____ ____ secondary to what conditions?
Decreased ventilation
- damage to resp centers
- emphysema
- pneumonia
214
Condensation of respiratory acidosis
Buffers in the body fluids
Kidneys increase NH4+ and titratable acid secretion, complete reabsorption of HCO3-, and generate new HCO3-
215
Respiratory alkalosis is caused by what?
Over-ventilation
216
Resp alkalosis rarely occurs ____, but can occur due to:
Pathologically
Psychological disturbances
217
Resp alkalosis may occur when:
A person ascends to high altitudes. As they breathe more to get O2, they lose more CO2, causing alkalosis
218
Compensation of resp alkalosis
Chemical buffers in the body fluids
Kidneys increase in HCO3- excretion (i.e decreasing ECF bicarbonate)
219
Metabolic acidosis is caused by:
Decreased extracellular fluid bicarbonate concentration
220
Extracellular fluid bicarb concentration can occur due to what?
Renal tubular acidosis (defect in renal secretion of H+, or reabsorption of HCO3- or both as seen in chronic renal failure, Addison’s dz, and some hereditary disorders
Diarrhea or vomiting from deep intestinal tract
Diabetes mellitus
Ingestion of excess acids (overdose on aspirin, methanol)
221
Compensation of metabolic acidosis
Increased resp rate to eliminate CO2
Renal compensation
222
Metabolic alkalosis is caused by:
Increase in ECF bicarb concentration
223
What cause cause an increase in ECF bicarb concentration
Some diuretics
Excess aldosterone
Vomiting of gastric contents
Ingestion of base (antacids for the tx of peptic ulcers, or gastritis)
224
Compensation of metabolic alkalosis
Decreased resp to increase CO2
Renal compensation
225
Diagnosis of an acid-base disorder begins with ____ ___ ____ analysis of what?
Arterial blood gas (ABG)
- pH
- Plasma bicarb concentration
- PCO2
226
ABG analysis steps
1- pH determines acidosis vs alkalosis
2- distinguish between resp and metabolic by looking at bicarb and PCO2 levels
227
Review slide 92 and 93
Slide 92 and 93
228
Purpose of the anion gap
It is used to give further diagnostic clues as to the cause of metabolic acidosis (ONLY met acidosis)
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Anion gap equation
AG = [Na+] - [HCO3-] - [Cl-]
230
AG represents what?
The unmeasured ions in a patient’s serum
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Normal AG value
8 - 16 mEq/L
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Compensation with an increase in plasma Cl- causes a _____ anion gap (______)
Normal
| Hyperchloremic metabolic acidosis
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Situations that could cause hyperchloremic metabolic acidosis
Diarrhea
Renal tubular acidosis
Carbonic anhydrase inhibitors (acetazolamide)
Addison’s disease (hypoaldosteronism)
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Compensation with an increase in another (unmeasured) anion leads to _____ anion gap (____)
An increased
Normochloremic metabolic acidosis
235
What can cause normochloremic metabolic acidosis
Diabetes mellitus (ketoacidosis)
Lactic acidosis
Chronic renal failure
Aspirin ingestion
Methanol poisoning
Ethylene glycol
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Relevant anatomy of the bladder
Body
Trigone (smooth, no rugae)
bladder neck (post urethra)
Internal sphincter (smooth muscle)
External sphincter (skeletal muscle)
Detrusor muscle (smooth muscle of bladder body)
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Sympathetic Innervation of the bladder
To blood vessels of the bladder
238
Parasympathetic innervation of the bladder
To smooth muscle
239
Pudendal nerve goes to what?
External sphincter (we have control of)
240
Urine from the collecting ducts empty into the what?
Calyces
241
Distention of the calyces initiates:
Peristaltic waves in smooth muscle that spread down the ureters
242
What innervation enhances peristalsis?
Inhibits peristalsis?
Parasympathetic
Sympathetic
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Peristalsis near the Trigone does what?
Opens the ureter as it passes through the detrusor muscle
244
As the bladder distends, what does the detrusor tone do?
Prevents back flow of urine
245
What gets stimulated as the bladder fills?
Sensory stretch receptors
246
Reflex stimulation of parasympathetic nerves cause what?
Intermittent micturition contractions
247
What facilitates the micturition reflex?
Voluntary relaxation of the external sphincter and pressure from abdominal contractions
248
What prevents micturition
Contraction of the external sphincter
249
All diuretics cause ___ ___ of water. Some lead to:
Increase excretion
Excretion of other solutes
250
What are reasons a pt may be prescribed diuretics?
Heart failure
Liver cirrhosis
Hypertension
Water intoxication
Some kidney diseases
251
What do diuretics do?
Make you excrete more water
252
Types of diuretics
Osmotic diuretics
Loop diuretics
Thiazides
Carbonic-anhydrase inhibitors
Competitive inhibitors of aldosterone
Na challenge blockers
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What do osmotic diuretics do?
Decrease water reabsorption by increasing tubular osmotic pressure; diuretic is filtered but poorly reabsorbed
254
What do ;loop diuretics do?
Inhibits Na+/Cl-/K+ cotransporter in ascending loop of henle
255
What does thiazide do
Inhibits Na+/Cl- reabsorption in early distal tubule
256
What do carbonic-anhydrase inhibitors do
Inhibits this enzyme present in the proximal convoluted tubule;
H+ secretion and HCO3- reabsorption is coupled to Na+ reabsorption
257
What do competitive inhibitors of aldosterone do?
Bind to the aldosterone binding site therefore blocking Na reabsorption. These are “potassium sparing” diuretics
258
What do sodium channel blockers do?
Inhibits the sodium channels in the collecting tubules. These are also “potassium sparing” diuretics
259
Types of acute renal failure
Rerenal
Intracranial
Postrenal
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Prerenal failure is due to what
Reduction in renal blood flow
261
Intrarenal failure is due to what?
Abnormalities of the kidney itself
262
Postrenal failure is due to what
Obstruction of the urinary collecting system
263
Causes of prerenal failure
Sudden and severe drop in blood pressure (shock) or interruption of blood flow to the kidneys from severe injury or illness
264
Causes of intrarenal failure
Direct damage to the kidneys by inflammation, toxins, drugs, infection, or reduced blood supply
265
Causes of postrenal failure
Studded obstruction of urine flow due to enlarged prostate, kidney stone, bladder tumor or injury
266
Acute pre-renal failur occurs _____ the kidney, usually due to a diminished ____ __, or ___ ___
Outside
Blood volume
Blood pressure
267
Causes of pre-renal acute failure
Hemorrhage
Diarrhea/vomiting
Burns
Cardiac failure
Anaphylactic shock
Renal artery stenosis/embolism/thrombus
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Abnormality within the kidney such as condition that injure intrarenal vessels, the nephron itself, or the renal interstitium
Intrarenal acute
269
Causes of intrarenal acute failure
Vasculitis (of renal vessels or glomerulus)
Glomerulonephritis
Tubular necrosis (due to ischemia, toxins)
Pyelonephritis (infection)
270
Causes of post-renal acute failure
Bilateral obstruction of the ureters (stones, blood clots)
Bladder obstruction
Urethra obstruction
271
Features of acute renal failure
Retention of water, salt and waste products of metabolism
Leads to edema and hypertension
Retention of potassium can lead to heart arrhythmia and death
Metabolic acidosis
272
Is there is complete Anuria, patients die within:
8-14 days
Before kidneys completely shut down
273
Progressive and irreversible loss of functional nephrons
Chronic renal failure
274
Common causes of chronic renal failure
Diabetes mellitus (most common)
Hypertension
Glomerulonephritis
Vascular disease
Polycystic disease
Renal hypoplasia
Obstructive nephropathy (stones, enlarged prostate)
275
Primary kidney disease causes:
| Cycle
Nephron number to decrease
Hypertrophy and vasodilation of surviving nephrons
And increased in arterial pressure
Increase in glomerular pressure and/or filtration
Glomerular sclerosis
276
When kidney damage is severe enough to require dialysis or transplant
End stage renal disease
