chapter 4 - fluids & electrolytes, acids and bases

Question 1

filtration

Answer 1

movement of water and solutes through a membrane because of force on one side of the membrane than on the other side.

Question 2

hydrostatic pressure

Answer 2

mechanical force of water pushing against cellular membrane

Question 3

osmosis

Answer 3

the movement of water “down” a concentration gradient across a semipermeable membrane from a region of higher water concentration to lower concentration.

Question 4

osmolarity

Answer 4

measures the number of mOsm/kg of water, or the concentration of molecules per weight of water.

Question 5

edema

Answer 5

excess accumulation of fluid within the interstitial spaces.
causes: increase capillary hydrostatic pressure, decrease in oncotic pressure, increases in capillary permeability, lymph destruction
localized vs generalized

Question 6

Sodium

Answer 6

primary ECF cation (+ion)

regulates osmotic forces, thus water

Question 7

Chloride

Answer 7

Primary ECF anion (-ion)

provides electroneutrality

Question 8

Sodium and chloride balance regulated by:

Answer 8

Kidneys
RAAS -Aldosterone (Influenced by blood volume, BP and Na and K concentrations)
Natriuretic Peptides - antagonist to aldosterone

Question 9

Anti-Diuretic Hormone (ADH)

Answer 9

maintains water balance,
secreted in response to a water deficit or sodium excess.
Thirst perception - stimulates more water intake

Question 10

Isotonic Alterations

Answer 10

total body water change with proportional electrolyte and water change (no change in concentration)

Question 11

Isotonic fluid loss

Answer 11

causes Hypovolemia - decrease of blood volume in the body. hemorrhage, severe diaphoresis, inadequate fluid intake

Question 12

isotonic fluid excess

Answer 12

causes hypervolemia (fluid overload)

Question 13

hypertonic alterations

Answer 13

caused by too much sodium or not enough water causing cells to shrink.
increase in ECF sodium concentration (hypernatremia) resulting in osmotic attraction of water out of cells with cell shrinkage

Question 14

hypernatremia

Answer 14

Serum sodium is greater than 145mEq/L

causes: increased sodium retention (due to aldosterone oversecretion)

Question 15

hypernatremia

Answer 15

serum sodium level less than 135 mEq/L
causes: 
loss of sodium - excessive sweating, vomiting, hormone imbalance
Excessive water intake/water excess
Manifestations:
intracellular over-dehydration
lethargy and confusion

Question 16

water excess

Answer 16

Causes: compulsive water drinking, decrease urine formation
hyponatremia with hypervolemia
manifestation: weakness, muscle twitching and weight gain

Question 17

Potassium

Answer 17

major cellular cation

Concentration maintained by Na+/K+ pump and kidneys

Question 18

Why is potassium important

Answer 18

Maintains electrical neurality
conduction of nerve impulses
transmission of cardiac rhythms
muscle contraction

Question 19

Hypokalemia

Answer 19

Potassium level below 3.5 mEq/L
Potassium moves out of cells into ECF to maintain balance
causes: 
reduced intake of potassium
increased entry of potassium into cells
increased loss of potassium
Manifestations: 
vary depending on speed and amount
weakness and dysrhthmias

Question 20

hyperkalemia (rare because of efficient renal excretion)

Answer 20

Potassium levels above 5.5 mEq/L
Causes: increased intake 
shift of K+ from ICF into ECF
 cell trauma
Decreased renal excretion
Hormone deficit
Manifestations:
vary with rate and severity, restlessness, dysrhytmias