CH 14: Fluid and Electrolytes Flashcards Preview

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Flashcards in CH 14: Fluid and Electrolytes Deck (40):
1

Acidosis

an acid-base imbalance characterized by an increase in H+ concentration (decreased blood pH).

2

Metabolic acidosis

A low arterial pH due to reduced bicarbonate concentration.

3

Respiratory acidosis

A low arterial pH due to increased PCO2.

4

Active transport

physiologic pump that moves fluid from an area of lower concentration to one of higher concentration; requires ATP for energy.

5

Alkalosis

an acid-base imbalance characterized by a reduction in H+ concentration (increased blood pH).

6

Metabolic alkalosis

A high arterial pH with increased bicarbonate concentration.

7

Respiratory alkalosis

A high arterial pH due to reduced PCO2.

8

Diffusion

the process by which solutes move from an area of higher concentration to one of lower concentration; does not require expenditure of energy.
Ex: the exchange of oxygen and carbon dioxide between the pulmonary capillaries and alveoli and the tendency of sodium to move from the ECF compartment, where the sodium concentration is high, to the ICF, where its concentration is low.

9

Homeostasis

maintenance of a constant internal equilibrium in a biologic system that involves positive and negative feedback mechanisms.

10

Hydrostatic pressure

the pressure created by the weight of fluid against the wall that contains it. In the body, hydrostatic pressure in blood vessels results from the weight of fluid itself and the fore resulting from cardiac contraction.

11

Hypertonic solution

A solution with an osmolality higher than that of serum.

12

Hypotonic solution

a solution with an osmolality lower than that of serum.

13

Isotonic solution

A solution with the same osmolality as serum and other body fluids. Osmolality falls within normal range for serum; 280-300 mOsm/kg.

14

Osmolality

the number of osmoles per kilogram of solution. Used to evaluate serum and urine.

15

Osmolarity

the number of osmoles per liter of solution; describes the concentration of solutes or dissolved particles.

16

Osmosis

the process by which fluid moves across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration; the process continues until the solute concentrations are equal on both sides of the membrane.

17

Tonicity

-fluid tension within the extracellular fluid or intracellular fluid that describes the relationship between the solutes and water, primarily determined by fluid osmolality.
-is the ability of all the solutes to cause an osmotic driving force that promotes water movement from one compartment to another.

18

S/S of 3rd spacing

decreased urine output despite adequate fluid intake
increased hr
decreased BP
decreased central venous pressure
edema
increased body weight
I/O imbalance

19

3rd spacing

loss of ECF into a space that does not contribute to equilibrium between the ICF and the ECF.

20

3rd spacing is common in patient's with....

hypocalcemia
decreased iron intake
severe liver diseases
alcoholism
hypothyroidism
malabsorption
immobility
burns
cancer

21

Major cations in body fluids are....

sodium
potassium
calcium
magnesium
hysdriogen

22

Major anions of body fluids are...

chloride
bicarbonate
phosphate
sulfate
proteinante ions

23

Osmotic pressure

the amount of hydrostatic pressure needed to stop the flow of water by osmosis. It is primarily determined by the concentration of solutes.

24

Oncotic pressure

The osmotic pressure exerted by proteins. (albumin)

25

Osmotic diuresis

the increase in urine output caused by the excretion of substances such as glucose, mannitol, or contrast agents in the urine.

26

Sodium-Potassium Pump

actively moves sodium from the cell into the ECF. Potassium is also pumped into the cell.

27

Chief solutes in sweat are...

Sodium
Chloride
Potassium

28

Osmolality measures....

the solute concentration per kilogram in blood and urine. It is also a measure of a solution's ability to create osmotic pressure and affect the movement of water.

29

Urine osmolality is determined by....

urea, creatinine, and uric acid.

30

Serum osmolality primarily reflects...

the concentration of sodium, although blood urea nitrogen (BUN) and glucose also play a major role in determining serum osmolality.

31

Normal osmolality in health adults

Serum osmolality is 280-300 mOsm/kg
Urine osmolality is 200-800 mOsm/kg

32

Urine specific gravity

Measures the kidneys' ability to excrete or conserve water. Normal range of urine specific gravity is 1.010 to 1.025.

33

Factors that increase BUN

decreased renal function
GI bleeding
dehydration
increased protein intake
fever
sepsis

34

Factors that decrease BUN

end-stage liver disease
low-protein diet
starvation
any condition that results in expanded fluid volume (pregnancy)

35

Normal serum creatinine

0.7 - 1.4 mg/dL
Levels increase as renal function decreases.

36

Hematocrit

measures the volume percentage of red blood cells in whole blood and normally ranges from 42% to 52% men; 35% to 47% women.

37

Major functions of the kidney in maintaining normal fluid balance include the following:

-regulation of ECF volume and osmolality by selective retention and excretion of body fluids.
-regulation of normal electrolyte levels in the ECF by selective electrolyte retention and excretion
-regulation of pH of the ECF by retention of hydrogen ions
-Excretion of metabolic wastes and toxic substances.

38

ADH

-manufactured by the hypothalamus
-is stored in the posterior pituitary gland and released as needed to conserve water.

39

Aldosterone

-a mineralocorticoid
-secreted by the zona glomerulosa (outer zone) of the adrenal cortex
-has profound effect on fluid balance
-increased secretion causes sodium retention and potassium loss
-decreased secretion causes sodium and water loss and potassium retention

40

Parathyroid glands

-embedded in the thyroid gland
-regulate calcium and phosphate balance by means of PTH
-PTH influences bone resorption, calcium absorption from the intestines, and calcium reabsorption from the renal tubules.