electrolyte/ pH balance

Question 1

how are fluid, electrolyte, and ph’s balanced?

Answer 1

mainly be adjusting urine concentration and volume!

Question 2

2 fluid compartments?

Answer 2

ICF and ECF

Question 3

what is ICF?

Answer 3

intracellular fluid

• in the cytosol
• lots of K+, protein, magnesium, HPO4

Question 4

what is ECF?

Answer 4

extracellular fluid

• interstitial fluid (sodium, chloride, HCO3)
• plasma (sodium, chloride, HCO3, protein)

Question 5

can water move between the compartments?

Answer 5

yes, osmolarity is similar in all compartments

Question 6

what is osmolarity

Answer 6

moles of solute contributing to osmotic pressure

Question 7

todal body fluid?

Answer 7

25 L of ICF
15 L of ECF
total 40L

Question 8

fluid is inputed by?

Answer 8

drinks, food, metabolism

Question 9

fluid output?

Answer 9

urine, exhalation, sweat, feces

Question 10

dehydratione effect on plasma osmolarity and plasma volume?

Answer 10

plasma osmolarity increases, plasma volume decreases

Question 11

effect of plasma osmolarity increasing from dehydration?

Answer 11

osmoreceptors in hypothalamus—> THIRST

Question 12

effect of plasma volume decreasing from dehydration?

Answer 12

baroreceptors in arterioles —> THIRST

Question 13

THIRST has 2 possible effects?

Answer 13

increased ADH release, or increased fluid intake (which results in rapid H20 reabsorption from small intestine)

Question 14

increased ADH release and the baroreceptors in arterioles begins what system?

Answer 14

renin angiotension aldosterone system in the kidneys

• aldosterone increases sodium reabsorption
• water reabsorption increases

Question 15

result of RAAS?

Answer 15

decreased urine volume (less water lost)

Question 16

electrolyte balance is important in?

Answer 16

• water balance (blood volume and pressure)
• acid base balance (H+ concentration)
• electrochemical gradients (neuromuscular function)
• cellular metabolism

Question 17

sodium affects?

Answer 17

blood volume and nerve/muscle function

Question 18

natriuretic peptides causes on sodium

Answer 18

decreased Na+ reabsorption and decreased aldosterone secretion

Question 19

aldosterone effect on sodium

Answer 19

increases Na+ reabsorption from DCT

Question 20

cortisol and estrogen effects on sodium

Answer 20

alodsterone like effects on sodium levels

Question 21

hypernatremia?

Answer 21

high levels of sodium in the blood

Question 22

hyponatremia?

Answer 22

low levels of sodium in the blood

Question 23

what does potassium affect?

Answer 23

nerve and muscle function (electrochemical gradients)

Question 24

when is K+ secreted?

Answer 24

when Na+ is reabsorbed (na/k exchange pump) increases potassium lost in urine

Question 25

when filtrate is acidic, NaCl is exchanged for?

Answer 25

H+ instead, so Na/H exchange pump decreases the potassium lost in urine must replenish with dietary sources

Question 26

hyperkalemia?

Answer 26

high potassium levels, medical emergency

Question 27

hypokalemia?

Answer 27

low potassium levels

Question 28

what is calcium important for?

Answer 28

neuromuscular function, coagulation, intracellular signalling, coenzyme

Question 29

hormonal regulation of calcium is by?

Answer 29

parathyroid hormone and calcitonin | -parathyroid hormone increases calcium reabsorption in DCT and absorption in intestine to increase calcium in blood

Question 30

hypercalcemia?

Answer 30

increased calcium levels

Question 31

hypocalcemia?

Answer 31

decreased calcium levels

Question 32

what is also regulated by PTH and affects calcium levels?

Answer 32

phosphate levels | -increased phosphate decreases PTH, more calcium excretion

Question 33

what is pH a measure of

Answer 33

concentration of hydrogen ion

Question 34

increased concentration of H+ effect on pH?

Answer 34

pH is less than 7, acidic

Question 35

decreased concentration of H+ effect on pH?

Answer 35

pH is more than 7, basic (alkaline)

Question 36

normal pH of plasma and ECF?

Answer 36

7.35-7.45, slightly basic

Question 37

what is acidosis

Answer 37

lower than normal pH, pH is less than 7.35

Question 38

what is alkalosis

Answer 38

abnormally high pH, pH is more than 7.45

Question 39

pH in the blood is tightly regulated so deviations?

Answer 39

are extremely dangerous!

Question 40

metabolic processes typical effect on blood pH?

Answer 40

lower blood pH, main problem is acidosis

Question 41

metabolic processes that lower blood pH?

Answer 41

respiration: increases CO2- carbonic acid anaerobic metabolism: lactic acid lipid metabolism: fatty acids protein metabolism: amino acids/ keto acids

Question 42

what are the 3 main buffering systems to maintain pH?

Answer 42

buffers respiratory system urinary system

Question 43

buffers function?

Answer 43

to reduce changes in pH by binding or releasing hydrogen

Question 44

protein buffer system=

Answer 44

most common buffering mechanism in plasma and ICF | -amino acids in proteins can accept or release hydrogen

Question 45

phosphate buffer system=

Answer 45

monohydrogen phosphate buffers acid in ICF and urinary filtrate

Question 46

bicarbonate buffer system=

Answer 46

main buffering mechanism in ECF, | -HCO3- (bicarbonate ion) mops up H+

Question 47

respiratory system as a buffering system?

Answer 47

acidosis stimulates resp centers, increases resp rate and "blows off" CO2

Question 48

urinary system as a buffering system?

Answer 48

pH of urine varies (4.5-8) - renal correction of acidosis is an increase in secretion of H+ to excrete acidic urine and reabsorption bicarbonate iron - renal correction of alkalosis is an increase in reabsorption of H+ and secretion of bicarbonate iron to excrete alkaline urine