Sodium and Water Balance

Question 1

What is BUN?

Answer 1

Blood, urea, nitrogen

Measurement of kidney function

Question 2

What are the normal values of BUN?

Answer 2

6-20 mg/dl

Question 3

What is formed in the liver as a by-product of protein metabolism and is excreted by the kidney?

Answer 3

BUN

Question 4

What is Creatinint?

Answer 4

Marker of GRF, product of creatine metabolism in the muscle

Question 5

What are normal creatinine values?

Answer 5

0.6-1.2 mg/dl

Question 6

What are normal sodium values?

Answer 6

135-145 meq/L

Question 7

What are normal K values?

Answer 7

3.5-5 meq/L

Question 8

What are normal Cl values?

Answer 8

98-106 meq/L

Question 9

What is normal values for HCO3?

Answer 9

24-31 meq/L

Question 10

What is the normal value of anion gap?

Answer 10

8-12 meq/L

Question 11

Osmosis is driven by what?

Answer 11

Concentrations, from high to low

Question 12

Solutes that freely cross the membrane do not create what?

Answer 12

osmotic or oncotic pressure gradient

Question 13

What is the equation for serum osmolarity?

Answer 13

(2x Na + B.S. / 18) + BUN/2.8

Question 14

What usually determines serum osmolarity?

Answer 14

serum Na

Question 15

What are ineffective osmolytes?

Answer 15

Na, B.S., BUN

Question 16

Why are some osmolytes ineffective?

Answer 16

Because they flow freely across the vascular endothelium

Question 17

What is an example of an effective osmolyte?

Answer 17

Albumin

Question 18

Why is albumin an effective osmolyte?

Answer 18

It does not readily cross teh endothelium

Question 19

What is responsible for clinical manifestations of hyponaturemia or hypernaturemia?

Answer 19

Changes in brain cell volume, celluar edema, or cell dehydration

Question 20

Water and sodium balance are regulated ________?

Answer 20

independently

Question 21

What is the clinical manifestation of having too much water?

Answer 21

hyponatremia (low plasma sodium concentration)

Question 22

What is the clinical manifestation of having too little water?

Answer 22

hypernatremia (high plasma sodium concentration)

Question 23

What is the clinical manifesation of having too much sodium?

Answer 23

volume expansion (edema)

Question 24

What is the clinical manifestation of having too little sodium?

Answer 24

Volume depletion

Question 25

The concentration of fluid describes the relationship of what, but doesn't tell us what?

Answer 25

Describes the relationship of the number of particles and the volume of fluid Doesn't tell us about the total amount of particles and water

Question 26

If you added particles in a compartment that had a fully permeable membrane, where would the particles and water distribute?

Answer 26

Equally across both sides

Question 27

If you added particles in a compartment that had a semipermeable membrane, where do the water and particles distribute?

Answer 27

Only the water can cross, but the particles can't, but water follows the particles, so the water comes from across the semipermeable membrane to equal out the water concentration

Question 28

What makes up extracellular fluid?

Answer 28

Interstitial fluid and plasma

Question 29

How much % of total body water is our weight?

Answer 29

60%

Question 30

How much of our total body water is from our intracellular fluid?

Answer 30

40%

Question 31

How much of our total body water is in the extracellular fluid?

Answer 31

20%

Question 32

Efferent arterioles, as they leave the glomerular capillaries, give rise to what? And what does that do?

Answer 32

peritubular capillaries; form venules to return blood to the system circulation (IVC)

Question 33

The nephron is responsible for what, in regards to our chemical environment? How can we measure this?

Answer 33

Our internal chemical environment; Measured by serum BUN and Creatinine

Question 34

Normal renal function requires what?

Answer 34

adequate blood flow to nephrons AND an adequate number of functioning nephrons

Question 35

What is the filtration pressure at the arteriolar end of the capillar?

Answer 35

30

Question 36

What is filtration?

Answer 36

Movement of fluid into teh interstitum

Question 37

What controls filtration pressure?

Answer 37

metarterioles

Question 38

If systemic BP increases, what will happen to the arterioles?

Answer 38

the arterioles vasoconstrict to maintain a constant filtration pressure

Question 39

If arterioles don't maintain a constant filtration pressure?

Answer 39

Edema formation will result (excessive fluid in the interstitial space)

Question 40

Albumin favors movement of fluid how in relation to the capillary?

Answer 40

Favore movement of fluid into the capillary

Question 41

At the arteriolar end of the capillary, filtration pressure favors movement of fluid where?

Answer 41

into teh tissues

Question 42

At the venous end of the capilary, oncotic or osmotic forces favor fluid movement where?

Answer 42

back into the circulation for absorption

Question 43

As fluids move from the capillary to the interstitial space, what happens to the filtration and osmotic pressures?

Answer 43

Filtration pressure decreases, osmotic pressure increases

Question 44

What happens to the remaining fluid in the interstitial space?

Answer 44

it's returned to the venous circulation by the lymphatic vessels

Question 45

Fluid exchange across the capillaries refers to what kind of forces?

Answer 45

Starling

Question 46

Glomerular capillary hydrostatic pressure is what compared to systemic capillary pressures?

Answer 46

Higher

Question 47

Glomerular capillary is more what compared to the systemic capillary?

Answer 47

permeable