Final Exam review Flashcards
Safety factors that prevent edema include all except:
A.
Accumulation of interstitial proteins.
B.
Washdown of interstitial fluid proteins.
C.
Variable lymphatic drainage.
D.
Low interstitial compliance.
A.
Accumulation of interstitial proteins.
The kidneys normally receive about what percentage of cardiac output?
A.
14%
B.
21%
C.
29%
D.
10%
B.
21%
The functions of the kidney are many and varied. Which of the following is NOT a function of the kidney?
A.
Regulation of fluid volume and body fluid composition.
B.
Release of ADH.
C.
Excretion of metabolic waste and foreign chemicals.
D.
Secretion of certain hormones.
B. Release of ADH
What percent of nephrons are juxtamedullary?
A.
They are 50-50 split with cortical nephrons.
B.
In humans, about 15% are juxtamedullary nephrons.
C.
In humans, there are no juxtamedullary nephrons.
D.
In humans, about 85% of the nephrons are extramedullary.
B.
In humans, about 15% are juxtamedullary nephrons.
Hypoglycemia is more likely to occur in the diabetic surgical patient with which of the following diseases?
A.
Manic-depressive disorder treated with lithium
B.
Chronic obstructive lung disease treated with a terbutaline inhaler and aminophylline
C.
Rheumatoid arthritis requiring high-dosage prednisone
D.
Renal disease
D.
Renal disease
The osmolarity of plasma is primarily due to:
A.
Potassium
B.
Magnesium
C.
Sodium
D.
Protein
E.
Calcium
C.
Sodium
Hyponatremia due to cortisol and aldosterone deficiency, aldosterone deficiency causes sodium wasting, and cortisol deficiency results in the increased antidiuretic hormone. Which pathology is the most likely cause?
A.
Addison’s disease
B.
Diabetes insipidus
C.
Delirium or dementia
D.
Trauma with long bone fractures
A.
Addison’s disease
Differences between intracellular and extracellular fluid composition include all of the following except:
A.
Sodium levels are higher in the extracellular fluid.
B.
Potassium levels are much higher in the intracellular fluid.
C.
Phosphate levels are greater in the extracellular fluid.
D.
The osmolarity of intracellular and extracellular fluids are similar.
E.
All the above are correct.
C.
Phosphate levels are greater in the extracellular fluid.
A serum sodium of 120mEq/liter is?
A.
Normal
B.
An indication of hyponatremia
C.
Due to hypertonic irrigating solutions
D.
An indication of hypernatremia
B.
An indication of hyponatremia
The major reabsorptive area of the nephron (where most reabsorption occurs) is:
a.
The proximal tubule
b.
The thick ascending limb of Henle’s loop
c.
The distal convoluted tubule
d.
The collecting ducts
e.
None of the above
a.
The proximal tubule
Because protein molecules are too large to be reabsorbed by normal mechanisms, a special mechanism called ________________ is used to save proteins.
a.
Symport
b.
Secondary active transport
c.
Pinocytosis
d.
Passive transport
c.
Pinocytosis
Net filtration pressure favoring filtration into Bowman’s space is closest to:
a.
40 mm Hg
b.
20 mm Hg
c.
10 mm Hg
d.
60 mm Hg
c.
10 mm Hg
All the following statements are true about the glomerular basement membrane except
a.
Large molecules easily pass through
b.
Maintains a strong negative charge
c.
Plasma protein filtration is prevented due to the strong negative electrical charge
d.
The membrane charge is due to glycoproteins
a.
Large molecules easily pass through
Decreased glomerular filtration causes overabsorption of sodium ions (Na+) and chloride ions (Cl − ) in the ascending limb of the loop of Henle resulting in a reduction in the delivery of these ions in the ultrafiltrate to the ________________, which are specialized cells designed to detect small changes in osmolality.
a.
Macula densa
b.
Afferent arteriole
c.
Mesangial cells
d.
Vasa recta
a.
Macula densa
Active transport of Cl is a feature of:
a.
The descending limb of Henle’s loop
b.
The thick ascending limb of Henle’s loop
c.
The proximal tubule
d.
The distal tubule
b.
The thick ascending limb of Henle’s loop
Glomerular filtration is also dependent on the following physiologic factors except:
a.
The pressure in the Bowman capsule
b.
The level of ADH present in the ultrafiltrate
c.
The colloid osmotic pressure of the plasma proteins
d.
The pressure inside the glomerular capillaries
b.
The level of ADH present in the ultrafiltrate
Which of the following statements about creatinine is/are true?
a.
Clearance can be used to estimate GFR.
b.
It is a byproduct of skeletal muscle metabolism.
c.
It is secreted in the proximal tubule to a limited extent.
d.
All the above
e.
None of the above
d.
All the above
Increased sodium delivery to the macula densa will:
a.
Increase water loss in collecting tubules.
b.
have no effect on GFR.
c.
increase GFR.
d.
decrease GFR.
d.
decrease GFR.
Filtration, which results from pressures forcing fluids and solutes through the glomerulus, is the first step in the formation of urine. The quantity of glomerular filtrate formed each minute in all nephrons is called the glomerular filtration rate (GFR). Normal GFR is approximately:
a.
5-6 L/min
b.
1.0-1.2 L/min
c.
125ml/min
d.
20-25% of cardiac output
c.
125ml/min
Urea passively diffuses from medullar collecting duct during water deficits when?
A.
The macula densa releases ADH
B.
In the presence of ADH
C.
Blood glucose levels are high
D.
The cortical osmolarity is 300mOsmol/L
B.
In the presence of ADH
Following this quiz, you go to the local pub drown your sorrows. After eating 2 bowls of the saltiest popcorn ever and drinking several cheap brews you are surprised that you have a strong urge to visit the restroom several times during your time there. Perplexed (because you didn’t study), you ask your wiser friend who explains why - despite a large sodium load - you still must urinate. The reason is:
A.
The alcohol has destroyed the hypertonic interstitium of the renal medulla.
B.
Alcohol has inhibited the release of ADH.
C.
Alcohol has inhibited the renin angiotensin pathway.
D.
Alcohol has inhibited angiotensin-converting enzyme.
B.
Alcohol has inhibited the release of ADH.
For which situations below would you expect to see increased stimulation for the release of ADH? (Pick all that apply)
A.
Ethanol, alpha-adrenergic agonists, and atrial natriuretic peptide.
B.
Hypovolemia
C.
Hypernatremia
D.
Elevations in osmolarity
B.
Hypovolemia
C.
Hypernatremia
D.
Elevations in osmolarity
The minimal obligatory urine volume of a normal 70 kg human is:
A.
50ml/day
B.
1200ml/day
C.
1L/day
D.
0.5L/day
D.
0.5L/day
________________ is a potent vasoconstrictor cleaved from angiotensin I primarily in the _______________ by the action of angiotensin-converting enzyme:
A.
Arginine Vasopressin, adrenal gland
B.
Cortisol, spleen
C.
Angiotensin II, primarily in the pulmonary endothelium
D.
Epinephrine, liver
C.
Angiotensin II, primarily in the pulmonary endothelium
Osmoreceptors which help regulate ADH secretion are mainly found where?
:A.
Hypothalamus
B.
Aorta and carotid vessels
C.
Left ventricle
D.
Adrenal medulla
A. Hypothalamus
RAAS activation produces which result in the body? (Pick 3)
A.
Increases circulating fluid volume.
B.
Promotes H2O and Na+ retention.
C.
Increases GFR.
D.
Increases blood pressure.
A.
Increases circulating fluid volume.
B.
Promotes H2O and Na+ retention.
D.
Increases blood pressure.
The renal medullary interstitial fluid is hyperosmolar compared to cortical interstitial fluid. Which factor contributes to this?
A.
Urea
B.
Active transport mechanisms
C.
ADH level
D.
All influence medullary osmolarity
E.
None of the above.
D.
All influence medullary osmolarity
Which statement about the macula densa is FALSE?
A.
It is in the proximal tubule.
B.
Specialized cells detect sodium concentration of the fluid in the tubule.
C.
Decreased fluid flow and sodium delivery and the macula densa responds by increasing renin release to increase GFR.
D.
Elevated tubule sodium triggers contraction of the afferent arteriole, reducing glomerular filtration rate.
A.
It is in the proximal tubule.
In which of the patients below would you expect to see decreased aldosterone secretion?
A.
A thirsty patient walking in the desert
B.
A patient with Conn’s syndrome
C.
A patient with hyperkalemia
D.
A patient taking Lisinopril
E.
None of the above
D.
A patient taking Lisinopril
Where is bicarb reabsorbed at?
Proximal tubule
Potential causes of metabolic alkalosis?
sodium depletion
long term diuretic
decreased aldosterone
Affects of acidosis
Decreased cardiac contractility,
Rightward shift in oxy-hemoglobin dissociation curve,
decreased responsiveness to catecholamines, K increases 0.6mEq/L for each 0.1 unit decrease in pH
The following 7.32, hco3 25, paco2 50
acidotic acute respiratory acidosis
Possible effective treatments for someone who has metabolic alkalosis
stop NG suction
IV hydrochloric acid
discontinue diuretics
Spironolactone if increased mineralocorticoid activity
Administer K
Name some body buffers
Bicarb
Hemoglobin
Intracellular proteins
Phosphate
Ammonia
Hydrogen ion pump exists in which tubule and is able to create a large hydrogen ion gradient
Distal tubule
Acidosis will have what effect on serum potassium
increases K 0.6 mEq/L for each 0.1 unit decrease in pH
Something that facilitates the hydration of carbon dioxide in plasma and erythrocytes. Carbonic acid which then spontaneously dissociates which spontaneously dissociates to hydrogen ion and bicarb. What do you need for this process.
Carbonic anhydrase
what do diuretics lead to?
Contraction alkalosis
What causes alkalosis?
The loss of acids through various things we do…like suctioning OG tubes, vomiting and diuretic administration.
Where in the tubule does carbonic anhydrase work?
The proximal tubule
Where is the majority of filtered bicarb reabsorbed?
80-90% of filtered bicarbonate is reabsorbed in the proximal tubule….with 10-20% reabsorbed in the distal tubule
Where is the sodium chloride symporter?
Distal convoluted tubule
How do most clinically used diuretics work?
By decreasing the rate of sodium reabsorption from the tubules which causes sodium output to increase (natriuresis) which then results in diuresis (water output)
What are osmotic diuretics
Mannitol/urea, glycerin, isosorbide, work in the proximal tubule by drawing fluid into the tubules
For AKI, HTN, acute oliguria
Causes increased intravascular volume which may cause pulmonary edema in CHF patients
What are loop diuretics?
Furosemide/bumetanide/ethacrynic acid… inhibit the Na-2Cl-K co-transporter in the TAL of Henle….the countercurrent multiplier gets disrupted and the interstitium cannot become hyperosmolar
Causes metabolic alkalosis, decreased lithium clearance, decreased K, decrease Ca, hypovolemia
What is the most used diuretic?
Thiazides (HCTZ)
How do thiazide diuretics work?
Inhibit sodium chloride reabsorption in the early distal tubule by affecting the NaCl cotransport mechanism
Cause Increased Ca, hyperglycemia, decreased K, and Hypochloremic metabolic alkalosis
What are carbonic anhydrase inhibitors?
Acetazolamide….Reduce reabsorption of Na+ in the proximal convoluted tubule by decreasing HCO3 and H2O reabsorption.
Causes mild metabolic acidosis
What is mainly used to treat glaucoma?
Carbonic anhydrase inhibitors
What is the disadvantage of carbonic anhydrase inhibitors?
It causes acidosis through bicarbonate loss in the urine.
What are aldosterone antagonists?
spironolactone (Aldactone), potassium-sparing, Decreases reabsorption of Na+ and decreases K+ secretion by competing for aldosterone (inhibits aldosterone) binding sites in the distal segment of the distal tubule.*
How are Na+ Channel blockers used for diuresis?
amiloride and triamterene….Decrease activity of Na/K ATPase in the collecting tubules and thereby decrease Na+ reabsorption
What is the #1 cause of renal failure?
DIABETES, 2nd leading cause is hypertension
What is the muscle relaxant of choice for renal patients?
Cis-atracurium as it is degraded by Hoffman elimination
Succinylcholine is safe in patients with K<____ mEq/L, will transiently increase K+ by almost ____ mEq/L
Safe with K < 5, will increase K by 0.5-1
What muscle relaxant should you avoid?
Pancuronium
What is the best analgesic because it doesn’t have any active metabolites?
Fentanyl
How does ANP work?
Decrease renin release, thereby decreasing circulating levels of angiotensin II and aldosterone. Promotes natriuresis and diuresis.
What is counter-regulatory to the RAAS system?
Natriuretic peptides
What are the actions of ANP
Inhibits renin release, increased GFR/vasodilation to promote diuresis, inhibits aldosterone secretion, inhibits ADH release, Acts directly on the collecting duct to decrease NaCl reabsorption
Where does ANP directly act to decrease NaCL reabsorption
The collecting duct
What is NOT in dialyzing fluid?
Phosphate, urea, urate, sulfate, or creatinine
What is High in dialyzing fluid?
Bicarb and glucose
What is low in dialysis fluid?
K, Na, Cl
Where does chloride transportation occur?
Active Na and Cl transport in the TAL increases the osmolality of the interstitial space
Where are the macula densa cells?
The TAL and distal tubule
What do the macula densa do
They are epithelial cells in the high cortical TAL and distal convoluted tubule that detect sodium concentration of the fluid in the tubule.
In response to elevated sodium, the macula densa trigger _____ of the afferent arteriole, reducing flow of blood to the glomerulus and the glomerular filtration rate.
Constriction
What cannot cross Bowman’s capsule?
Cells and proteins more than 60 to 70 kDa cannot cross.
What does the basement membrane block?
Negatively charged proteins are thus repelled and are unable to pass through it. Molecules greater than 50-100 angstroms will not pass through
What are the two major determinants of filtration pressure?
Glomerular capillary pressure (PGC) and glomerular oncotic pressure (pgc).
Renal blood flow is around ____% of cardiac output
20%
What are the two major regulatory functions performed by the juxtaglomerular apparatus?
The high distal tubular [NaCl]-induced afferent arteriolar vasoconstriction
the low tubular [NaCl]-induced renin release
What does a decrease in sodium chloride concentration initiate in the macula densa/JG?
1) It increases renin release from the juxtaglomerular cells of the afferent and efferent arterioles, which are the major storage sites for renin, and,
2) It decreases resistance to blood flow in the afferent arterioles, which raises glomerular hydrostatic pressure and helps return GFR toward normal.
When renin is released in response to decreased NA, it ____ the efferent arteriole, thus increasing GFR.
Constricts
Renin ___ the efferent arteriole in response to decreased NA to the JG apparatus.
Constricts
ANP ____ the afferent arteriole and also does what to the efferent?
vasodilates the afferent
Constricts the efferent
What would you see in a preop uremic patient?
Increased bleeding risk, Anorexia, nausea, vomiting, pruritus, anemia, fatigue, coagulopathy, edema, pericarditis, acidosis, high nitrogenous wate products (urea, uric acid, creatine), increase in K, anemia, a compensatory increase in C.O
When are buffers the most efficient?
When pH = pKa
What does the the Henderson–Hasselbalch equation describe?
The relationship between pH, PaCO2, and serum bicarbonate.
The solubility coefficient for CO2 is what?
0.03 mmol/mm Hg
What is by far the most powerful of the acid-base regulatory systems?
Kidneys
What are the buffers for acidosis?
Brain/arterial receptors, increased RR, decrease co2, decrease H2CO3 (carbonic acid), increase PH
What are the buffers for alkalosis
Decreased RR, increase co2, increase H2CO3, decrease PH
The _____ _____ _____ is the most powerful extracellular buffer in the body.
Bicarbonate buffer system
What type of cells are especially important in eliminating hydrogen ions while reabsorbing bicarbonate in acidosis?
Type A intercalated cells
What cells have functions opposite to those of type A cells and secrete bicarbonate into the tubular lumen while reabsorbing hydrogen ions in alkalosis?
Type B intercalated discs
what are the three primary systems that regulate the H+ concentration in the body fluids to prevent acidosis or alkalosis?
1) Chemical acid base buffer systems
2) respiratory center
3) Kidneys (Most important)
What causes metabolic alkalosis?
Na Depletion: more Na absorbed in proximal tubule, contraction alkalosis with long term diuretic use
Increased aldosterone (mineralcorticoid): increases Na reabsorption and H secretion in distal tubule
What causes an elevated anion gap in metabolic acidosis?
Three diseases (uremia, ketoacidosis, lactic acidosis)
Toxins (methanol, ethylene glycol, salicylates, paraldehyde)
Due to decreased excretion of non-volatile acids
What conditions of metabolic acidosis have a normal anion gap?
Anything with HCO3 loss:
Renal tubular acidosis
Diarrhea
Carbonic anhydrase inhibition
Ureteral diversions
Early renal failure
Hydronephrosis
HCl administration
Saline administration
What is considered a high anion gap?
> 13mEq/L
When is Sugammadex not indicated?
Severe renal insufficiency/failure
Peds
ICU patients
How is the Sugammadex complex mainly excreted?
Excreted by the kidneys mainly
Forms a stable complex with Roc that is then eliminated by the kidneys. In ESRD this complex remains in circulation for days
What is the key factor in causation of perioperative renal failure
Hypovolemia
When is gout most common?
When diet is rich in protein, fat, and alcohol
Signs and symptoms of uremic syndrome?
Anorexia
Nausea
Vomiting
Pruritus
Anemia
Fatigue
Coagulopathy
Acidosis
Increase in K, Phos, Phenols
Increased CO
Rate of movement of a solute across a membrane in dialysis depends on these three things
Concentration gradient of solute
Permeability of surface area of membrane
Length of time they remain in contact
Four components of the JGA
Smooth muscle in afferent
Smooth muscle in efferent
Extraglomerular mesangial
Macula densa in DISTAL TUBULE
Conn’s syndrome
Aldosterone secreting tumor that causes HTN, hypernatremia, hypokalemia
2 functions of the vasa recta
Remove reabsorbed fluid from the interstitium
Minimize solute uptake from the medulla (maintain hypertonicity)
Osmolality is defined as:
Answers:A.
Gram molecular weight per liter of solution
B.
Number of particles per 22.14 liters
C.
Osmoles per liter of solution
D.
Osmoles per kilogram of solution
D.
Osmoles per kilogram of solution
The proximal tubule does bulk reabsorption of what 2 things?
Solutes and H2O
The descending loop of Henle is highly permeable to what and utilizes what mechanism?
Utilizes the countercurrent mechanism and is highly permeable to H2O
The Ascending loop of Henle uses what mechanism and is not permeable to what?
Uses the countercurrent mechanism and is NOT permeable to H2O
The distal convoluted tubule is the location for what important part of the kidney and fine tunes the concentration of what?
Location of JGA
Fine tunes solute concentration
The collecting duct regulates the final concentration of what and has what three things working in that area?
Final concentration of urine
ADH, aldosterone, ANP work here
What can be used to treat glaucoma, high altitude sickness and central sleep apnea
Carbonic anhydrase inhibitors
What medications are bad to use in combination with potassium sparing diuretics?
NSAIDs, Beta blockers, ace inhibitors
What labs assess GFR
BUN
Serum Cr
CrCl
What labs assess tubular function?
FxNa
Osmolality
Gravity
Concentration
True or false: BUN goes through both filtration and reabsorption?
True
True or false: CrCl goes only through filtration?
True
What can excessive administration of 0.9% NaCl cause?
Hyperchloremic metabolic acidosis
What do alpha 1 agnonists cause in the kidneys?
Decreased renal blood flow
Which is constricted with vasopressin: afferent or efferent arterioles?
Efferent arterioles
How can you decrease K via ventilation?
Hyperventilate
Decreases K by 0.5mEq/L
When is dialysis indicated?
Severe metabolic acidosis
volume overload
hyperkalemia
symptomatic uremia
overdose with a drug that can be cleared
What narcotics should not be given with renal disease?
Morphine
Meperidine
