fluid, electrolyte, acid-base balance Flashcards
(116 cards)
1
Q
3 types of homeostatic balance:
A
fluid balance, electrolyte and acid-base balance
2
Q
major fluid compartments of the body
A
65% intracellular fluid
35% extracellular fluid
3
Q
water moves easily through __, osmotic gradients never last long
A
membranes
4
Q
if __ of the tissue fluid rises, water moves out of the cell
A
osmolarity
5
Q
if osmolarity of the tissue fluid falls, __
A
water moves in the cell
6
Q
sodium salts in
A
ECF
7
Q
potassium salts in
A
ICF
8
Q
plays the role of governing the bodys water distribution and total water content
A
electrolytes
9
Q
bodys two sources of water
A
preformed and metabolic water
10
Q
water ingested in food and drink
A
preformed water (2,300 mL/day)
11
Q
water formed by aerobic metabolism and dehydration synthesis
A
metabolic water (200 mL/day)
12
Q
sensible water loss is observable:
A
urine, feces, sweat
13
Q
insensible water loss is unnoticed:
A
expired breath, cutaneous transportation
14
Q
water output that is unavoidable
A
obligatory water loss:
expired air, cutaneous transportation, sweat, fecal moisture, and minimum urine output
15
Q
hypothalamic osmoreceptors produce signals in response to increased ECF osmolarity, antidiuretic hormone is produced
A
regulating water intake
16
Q
only way to control water output is through variation in __
A
urine volume
17
Q
cannot replace water or electrolytes
A
kidneys
18
Q
water output is slowed through action of
A
ADH
19
Q
ADH secretion is triggered by hypothalamic osmoreceptors in response to
A
dehydration (water output)
20
Q
in water output, __ are synthesized in response to ADH
A
aquaporins
21
Q
important for electrical signaling in nerve and muscle cells, sodium ions bound to the proteoglycans of cartilage retain water
A
sodium
22
Q
principal cation in ECF
A
sodium (Na+)
23
Q
source of energy for cotransport of other solutes
A
sodium
24
Q
generates body heat, major role of buffering pH in ECF
A
sodium
25
adult needs how much sodium per day
0.5 g
26
typical american diet contains how much sodium per day
3 to 7 g
27
kidneys reabsorb almost
no sodium
28
urine contains up to
30 g of sodium per day
29
natriuretic peptides inhibit
sodium reabsorption
30
plasma sodium concentration greater than 145 mEq/L, causes water retension, hypertension, and edema
hypernatremia
31
plasma sodium concentration less than 130 mEq/L, person loses large volumes of sweat or urine, replacing it with drinking water
hyponatremia
32
electrical signaling in nerve and muscle cells, responsible for resting membrane potential and repolarization and hyperpolarization of the action potential
potassium
33
most abundant cation of ICF
potassium
34
greatest determinant of intracellular osmolarity and cells volume
potassium
35
important for thermogenesis
Na+-K+ pump
36
90% of potassium in glomerular filtrate is reabsorbed by PCT, rest is excreted in
urine
37
stimulates renal secretion of K+
aldosterone
38
most dangerous types of electrolyte imbalances
potassium imbalances
39
plasma potassium concentration above 5.5 mEq/L, can produve cardiac arrest, nerve and muscle cells become less excitable
hyperkalemia
40
plasma potassium concentration less than 3.5 mEq/L, loss of muscle tone, decreased reflexes, and arrhythmias
hypokalemia
41
most abundant anion in ECF, major contribution to ECF osmolarity
chloride, CL-
42
required for the formation of stomach acid, accompanies C)2 loading and unloading in RBCs
chloride
43
major role in regulating body pH
chloride
44
as sodium is retained, __ ions follow
chloride
45
chloride imbalances disturb
acid base balance
46
result of dietary excess or administration of IV saline
hyperchloremia of chloride
47
lends strength to skeleton, activates sliding filament mechanisms of muscle contraction
calcium (Ca2+)
48
second messenger for some hormones and neurotransmitters, essential factor in blood clotting
calcium
49
activates exocytosis of neurotransmitters
calcium
50
cells maintain very low intracellular Ca2+ levels to prevent calcium phosphate
crystal precipitation
51
__ levels are high in the ICF
phosphate
52
cells must pump what out
calcium
53
protein that binds calcium and keeps it unreactive
calsequestrin
54
chiefly regulated by PTH, calcitriol (vitamin D), and calcitonin
calcium homeostasis
55
plasma calcium greater than 5.8 mEq/L, inhibits depolarization of nerve and muscle cells, reduces membrane Na+ permeability
hypercalcemia (calcium imbalance)
56
less than 4.5mEq/L calcium, increases membrane Na+ permeability
hypocalcemia
57
about 54% is in bone, and 45% in intracellular fluid
magnesium (Mg2+)
58
most intracellular Mg2+ is complexed with
ATP
59
serves as a cofactor for enzymes, transporters, and nucleic acids
magnesium
60
blood levels of magnesium
1.5 to 2.0 mEq/L
61
magnesium is lost in
feces and urine
62
plasma deficiency of magnesium
hypomagnesium
63
excess of magnesium in blood
hypermagnesium
64
relatively concentrated in ICF due to hydrolysis of ATP and other phosphate compounds
phosphate (Pi)
65
equilibrium mixture of phosphate, monohydrogen phosphate, and dihydrogen phosphate
inorganic phosphates
66
activates many metabolic pathways by phosphorylating enzymes and substrates such as glucose
phosphates
67
acts as a buffer that helps stabalize the pH of body fluids
phosphates
68
continually lost by glomerular filtrartion
phosphate
69
if plasma concentration drops, __ reabsorbs all filtered phosphate
renal tubules
70
increases excretion of phosphate which increases concentration of free calcium in the ECF
parathyroid hormone of phosphate
71
body can tolerate broad variations in
phosphate levels
72
what raises both Na+ and Cl-
blood plasma and ECF
73
aldosterone, ADH, ANP can all regulate what
sodium concentration
74
mostly reabsorbed by nephron, can secrete into nephron to lower blood levels, aldosterone can trigger this
potassium
75
passively follows anions
chloride
76
hormones affect bone deposition, maintains very low ICF levels
calcium
77
average diet provides enough of this, kidney can reabsorb __ if it gets low
phosphate
78
__ depends on enzymes, and enzymes are sensitive to pH
metabolism
79
slight deviation from __ can shut down entire metabolic pathways, alter structure and function of macromolecules
normal pH
80
pH of a solution is determined by its
hydrogen ions (H+)
81
any chemical that releases H+ in solution
acids
82
any chemical that accepts H+
bases
83
normal pH of blood and tissue fluid
7.35 to 7.45
84
any mechanism that resists changes in pH, converts strong acids or bases to weak ones
buffer
85
system that controls output of acids, bases, or CO2
physiological buffer
86
substance that binds H+ and removes it from solution as its concentration begins to rise or releases H+ into solution as its concentration falls
chemical buffer
87
3 major chemical buffers
bicarbonate, phosphate, and protein systems
88
buffer systems are mixtures composed of
weak acids and bases
89
coordinates with the lungs and kidneys to help control pH and CO2
bicarbonate buffer system
90
important buffering in the ICF and renal tubules
phosphate buffer system
91
more concentrated than bicarbonate or phosphate systems, especially in the ICF
proteins
92
the addition of C02 to the body fluids raises the H+ concentration and
lowers pH
93
increased pH inhibits
pulmonary ventilation
94
increased CO2 and decreased pH stimulates
pulmonary ventilation
95
respiratory system neutralizes two or three times as much __ as chemical buffers
acid
96
the addition of CO2 to the body fluids raises H+concentration and
lowers pH
97
renal tubules secrete H+ into the
tubular fluid
98
less CO2 =
high pH, more alkaline
99
more C02=
low pH, more acidic
100
blood pH below 7 or above 7.7 person will
die
101
__ can neutralize more acid or base than either the respiratory system or chemical buffers
kidneys
102
H+ binds to
bicarbonate, ammonia, and phosphate buffers
103
free H+ are excreted in the __
urine
104
membrane hyperpolarization, nerve and muscle cells are hard to stimulate
acidosis- pH of ECF below 7.35
105
membranes depolarized, nerves overstimulated, muscles causing spasms, tetany, convulsion, respiratory paralysis
alkalosis- pH abover 7.45
106
occurs when rate of alveolar ventilation fails to keep pace with the body's rate of CO2 production
respiratory acidosis
107
results from hyperventilation, CO2 eliminated faster than its produced
respiratory alkalosis
108
increased production of organic acids in anaerobic fermentation, and ketone bodies seen in alcoholism, ingestion of acidic drugs
metabolic acidosis
109
rare, but can result from overuse of bicarbonates, loss of stomach acid (chronic vomiting)
metabolic alkalosis
110
either the __ compensate for pH imbalances of respiratory origin, or the __ compensates for pH imbalances of metabolic origin
kidneys, respiratory system (compensated acidosis or alkalosis)
111
a pH imbalance that the body cannot correct without clinical intervention
uncompensated acidosis or alkalosis
112
changes in pulmonary ventilation to correct changes in pH of body fluids by expelling or retaining CO2
respiratory compensation
113
(excess CO2) stimulates pulmonary ventilation, alimating co2 and allowing pH to rise
hypercapnia
114
(deficiency of co2) reduces pulmonary ventilation to allow co2 to accumulate, which lowers pH
hypocapnia
115
slow, but better than restoring a normal pH, adjusted by changing rate of H+ secretion in kidneys
renal compensation
116
cannot act quickly enough to compensate for short term pH imbalances
kidneys
