kidneys, water balance, electrolytes

Question 1

water is filtered and reabsorbed by…

Answer 1

osmosis

Question 2

4th most abundant cation in the body

Answer 2

magnesium

Question 3

what is the major site of water reabsorption

Answer 3

proximal tubule

Question 4

what is reabsorbed in loop of henle

Answer 4

ions

Question 5

this hormone controls the isertion of aquaporin water channels necessary for water reabsorption in the collecting duct

Answer 5

ADH

Question 6

other names of ADH

Answer 6

argipressin
vasopressin
arginine vasopressin

Question 7

these are looped blood vessels which maintain the concentrated nature of the medullary interstitium

Answer 7

vasa recta

Question 8

this is best to use in kidney function test because it is a 100% waste product

Answer 8

creatinine

Question 9

what are the things to consider when doing creatinine clearance test to ensure accurate results

Answer 9

start collection with empty bladder
urinate in 24 hour period

Question 10

this is the most ideal substance for GFR

Answer 10

inulin or lothalamate (lo)

Question 11

___ is a polymer of fructose which is obtained from plants (dahlias, onions, garlic)

Answer 11

inulin

Question 12

the problem of this test is that it requires IV infusions and are more laborous and expensive

Answer 12

inulin or lotholamate clearance test

Question 13

clearance of this substance is the most accurate for GFR determination

Answer 13

inulin

Question 14

the reference method for GFR determination

Answer 14

inulin or lotholamate clearance test

Question 15

this measures the effective renal plasma flow (ERPF) in the absence of a tubular functional impairment

Answer 15

PAH clearance

Question 16

this substance is the most commonly used to assess secretory function of renal tubules

Answer 16

PAH clearance

Question 17

PAH clearance is dependent on the…

Answer 17

volume of blood perfusing the kidney (total renal blood flow)

Question 18

this is the reference method for ERPF determination

Answer 18

PAH clearance

Question 19

what are the two important properties of the ECF

Answer 19

volume and osmolality

Question 20

ECF volume is directly dependent on what substance

Answer 20

sodium

Question 21

ECF volume is maintaned by (2)

Answer 21

regulation of renal excretion of sodium or GFR, and aldosterone via the RAA system

Question 22

percentage of filtered sodium reabsorbed by the earlier parts of the renal tubules

Answer 22

70%

Question 23

what is the role of aldosterone in maintaining ECF volume

Answer 23

Sodium reabsorption
Release of potassium and hydrogen ions
because it is a vasoconstrictor

Question 24

what situations/conditions stimulates the juxtaglomerular cells of the kidneys to release renin

Answer 24

Hyponatremia
Hyperkalemia
Hypotension

Question 25

what kind of dehydration causes increased ECF osmolality

Answer 25

Pure water loss or deficit

Question 26

this type of dehydration have a normal sodium levels

Answer 26

pure water loss or deficit

Question 27

this type of dehydration have a less effect on plasma or ECF volume because the body easily compensates for the fluid loss by recruiting water from the ICF

Answer 27

pure water loss or deficit

Question 28

this type of dehydration have a greater effect on ECF or plasma volume

Answer 28

water and sodium loss

Question 29

what readily takes place in water and sodium loss especially in isotonic fluid loss

Answer 29

hypovolemia

Question 30

what are the different types of water and sodium loss and what causes them

Answer 30

Hypernatremic dehydration: water and food deprivation, excessive sweating, osmotic diuresis Normonatremic dehydration: vomiting, diarrhea Hyponatremic dehydration: diuretic therapy, salt-wasting renal disease, adrenocortical insufficiency

Question 31

this is the measure of solute/water ration (amount of dissolved particles)

Answer 31

osmolality

Question 32

what causes overhydration

Answer 32

Excessive intake of water (polydipsia) Excessive water reabsorption: SIADH and ectopic ADH secretion

Question 33

ECF osmolality is regulated by these substances

Answer 33

Na Cl HCO3 Glucose Urea Proteins

Question 34

what provides colloid osmotic pressure or oncotic pressure at te tissue interstitial fluid

Answer 34

proteins (globulin)

Question 35

what increases in pure water loss? And what does it trigger

Answer 35

ECF osmolality increases, which triggers release of ADH (released by posterior pituitary) or vasopressin via hypothalamic osmoreceptors, stimulation of the hypothaamic thirst center, and redistribution of water from the ICF

Question 36

where can serum hyperosmolality found and serum hypoosmolality

Answer 36

hyper- excessive water loss hypo- polydipsia

Question 37

this refres to the difference between the calculated osmolality using the equation (lower) and the measured osmolality using any of the above direct methods (higher)

Answer 37

delta osmolality

Question 38

this is used to evaluate acutely ill or comatose patients

Answer 38

delta osmolality

Question 39

what value suggests poor prognosis in delta osmolality

Answer 39

>40 mOsmol/kg H2O

Question 40

delta osmolality is increased in what situations

Answer 40

Ingestion of poison Ethanol overdose Azotemia

Question 41

this causes a large osmolar gap but does not cause an anion gap metabolic acidosis

Answer 41

isopropyl alcohol

Question 42

an osmolal gap of >10 is caused by...

Answer 42

Toxic alcohols Mannitol Lorazepam infusions

Question 43

they are used ot differentiate between pre-renal and renal causes of acute renal failure

Answer 43

RFI and FeNa

Question 45

this evaluates the concentration and diluting ability of the kidneys

Answer 45

osmol clearance

Question 46

it measures the amount of water cleared from the plasma resulting in urine that has the same osmolality as the plasma

Answer 46

osmol clearance

Question 47

this is used for the concentration and dilution ability of the kidneys

Answer 47

free water clearance

Question 48

this is calculated as the difference between the total urine volume and the osmol clearance

Answer 48

free water clearance

Question 49

if the free water clearance is positive....

Answer 49

the urine is dltuted compared to serum

Question 50

if free water clearance is negative...

Answer 50

the urine is more concentrated than serum

Question 51

enumerate situations where plasma osmolality is increased

Answer 51

dehydration alcohol intoxication hypercalcemia diabetes insipidus osmoticaly active drugs (mannitol)

Question 52

when is plasma osmolality decreased

Answer 52

water intoxication (polydipsia) inappropriate wtaer retention in kidneys (SIADH in asthma and pneumonia; ectopic secretion of ADH) bronchogenic cancer lymphosarcoma

Question 54

this is an indirect measure of ADH content

Answer 54

overnight water department test

Question 55

in overnight water department test, water is withheld from the patient for ___ hours

Answer 55

8

Question 56

in overnight water department test, patients with ADH deficiency have ___ serum osmolality and ___ urine osmolality over time

Answer 56

increasing, decreasing

Question 57

most abundant cation in the body

Answer 57

calcium

Question 58

major extracellular fluid anion

Answer 58

chloride

Question 59

most abundant cation in extracellular fluid

Answer 59

sodium

Question 60

major intracellular cation

Answer 60

potassium