Physio 1

Question 1

what happens to body fluid as you age?

Answer 1

decreases from approx 75% of weight in newborns to 50% in aged adults. extracellular fluid goes from 50% to 33%

Question 2

relationship between total body water and body fat

Answer 2

inversely proportional.

Question 3

body fluid balance

Answer 3

the kidneys maintain and monitor plasma volume and osmolarity which in turn maintains total body water and osmolarity due to water and solute exchange between ECF and ICF compartments

Question 4

what does unregulated water and salt loss from TBW occur through?

Answer 4

sweat, feces, and insensible skin and lung loss (H20 only)

Question 5

what drives fluid distribution between plasma and interstitial fluid?

Answer 5

balance between hydrostatic pressure and osmotic pressure differences across the capillary wall. depends on starling forces.

Question 6

filtration or reabsorption rate formula

Answer 6

Lp [(Pc-Pi)-(piC-piI)]

Question 7

solute distribution

Answer 7

similar between ISF and plasma with exception of negatively charged plasma proteins, which are impermeable to the capillary wall and remain within the intravascular compartment. accordingly, osmotic pressure is higher in plasma than ISF due to the absence of protein in the ISF

Question 8

edema

Answer 8

excess accumulation of fluid in the interstitial space due to cardiac, renal, hepatic, or endocrine dysfunction

Question 9

regulatory functions of the kidneys

Answer 9

extracellular fluid volume, fluid osmolarity, and fluid ion composition. clearance of metabolic end products, toxins, and drugs. endocrine functions such as erythropoietin, active vitamin D, and renin

Question 10

isosmotic fluid expansion

Answer 10

intravenous isosmotic fluid gain to ECF

Question 11

what happens to ICF and ECF volume and osmolarity when a volume of isosmotic solution is added to ECF?

Answer 11

intravenous isosmotic fluid gain to the ECF

Question 12

what happens during isosmotic volume contraction?

Answer 12

diarrhea, isosmotic/isotonic fluid loss from the ECF

Question 13

what happens during hyperosmotic volume contraction

Answer 13

profuse sweating and water deprivation (loss of water in excess of solute from the ECF)

Question 14

what happens during hyperosmotic volume expansion?

Answer 14

high NaCl intake without fluids, gain of solute in excess of water in the ECF

Question 15

what happens during hypoosmotic volume expansion

Answer 15

syndrome of inappropriate antidiuretic hormone (SIADH) - gain of water in excess of solute in the ECF. an inappropriate excess of circulating ADH causes an increase in water reabsorption from the renal tubule into ECF

Question 16

what happens during hypoosmotic volume contraction

Answer 16

adrenal insufficiency and decreased renal NaCl reabsorption (loss of solute in excess of water). aldosterone insufficiency iresults in decreased return of NaCl to the ECF

Question 17

what happens during hypoosmotic volume contraction

Answer 17

adrenal insufficiency and decreased renal NaCl reabsorption (loss of solute in excess of water). aldosterone insufficiency iresults in decreased return of NaCl to the ECF

Question 18

cell volume regulation

Answer 18

cells use solute transport mechanisms to change ICF volume.

Question 19

cell shrinking in response to an increase in ECF osmolarity

Answer 19

cells activate solute uptake mechanisms to increase ICF osmolarity, driving water into cells (regulatory volume increase RVI)

Question 20

cell swelling in response to a decrease in ECF osmolarity

Answer 20

cells activate solute efflux mechanisms to decrease ICF osmolarity driving water out of cells to restore volume to normal

Question 21

basic renal filtration

Answer 21

separation of an ultrafiltrate from the blood. done through glomerular capillaries

Question 22

basic renal reabsorption

Answer 22

directional movement of solutes and water from the lumen of the kidney tubule to the peritubular surface (blood side)

Question 23

basic renal secretion

Answer 23

directional movement of solutes from the peritubular side of the kidney tubule to the lumenal surface

Question 24

basic renal synthesis

Answer 24

metabolism within kidney cells degrading and creating organic solutes or hormones appearing in the blood or in the urine

Question 25

basic renal excretion

Answer 25

solute and water eliminated in the urine. not a renal process, but the end result of renal processes

Question 26

transport of water

Answer 26

filtration and osmosis

Question 27

transport of solute

Answer 27

passive diffusion and active transport