BSN 346 FINAL EXAM QUESTIONS AND
CORRECT ANSWERS!!
What physiologic and pathophysiologic conditions predispose an individual to disturbances
in fluid intake?
- habit
- social factors
- thirst
- trauma, infection, neoplasia, surgery --> disruption in physiological signals of thirst
- altered level of consciousness
- inability to acquire or physically drink fluids
- increasing age; cerebral osmoreceptor-mediated thirst diminishes in older adults
additional routes for fluid intake:
- IV
- tube in GI tract and other body cavities
- subcutaneous tissue or bone marrow
- rectal intake
- lungs (drowning)
How do the compositions of plasma and interstitial fluids differ? How are they similar?
Different:
- Plasma contains many proteins whereas interstitial fluid contains few proteins
Similar:
- relatively rich in sodium, chloride, and bicarbonate ions
- relatively low in potassium, magnesium and phosphate ions
What regulates water and electrolyte movement between plasma and interstitial fluids?
Across cell membranes?
,Between plasma and interstitial fluids:
- Water and electrolytes move across capillary walls by filtration, which is the net result of
opposing hydrostatic and colloid osmotic pressures in the capillary and the interstitial fluid
Across cell membranes:
- Water moves in and out of cells by osmosis, which is driven by unequal particle concentrations
on the two sides of the semipermeable cell membrane
- Electrolytes move across cell membranes through membrane channels or ion pumps
What are the usual and pathologic routes of fluid exit from the body?
Usual:
- urinary tract
- bowels
- lungs
- skin
Pathologic:
- emesis (vomiting)
- tubes in GI tract or other body cavities
- hemorrhage
- drainage from fistulas, wounds, or open areas of the skin
- paracentesis (the perforation of a cavity of the body or of a cyst or similar outgrowth, especially
with a hollow needle to remove fluid or gas)
Under what conditions are extracellular volume deficit and excess likely to occur, and what
are the characteristic clinical findings?
Extracellular fluid volume (ECV) deficit is likely to occur when there is removal of a sodium-
containing fluid from the body, such as with excessive gastrointestinal or renal excretion, or
other losses such as hemorrhage
Clinical findings of ECV deficit:
- sudden weight loss
,- postural blood pressure with increased heart rate
- flat neck veins
- oliguria
ECV excess can occur with excessive intravenous infusion of sodium-containing isotonic fluids,
and with renal retention of sodium and water
Clinical findings of ECV excess:
- sudden weight gain
- edema
- manifestations of circulatory overload
Under what conditions are the hypernatremia (water excess) and hyponatremia (water
deficit) likely to occur, and what are the characteristic clinical findings?
Hypernatremia:
- excessive antidiuretic hormone secretion
- hypotonic fluid intake
Clinical findings of hypernatremia:
- low serum sodium concentration
- confusion
- lethargy
- seizure
- coma due to cell swelling
Hyponatremia:
- inadequate water intake
- excessive water excretion or loss
Clinical findings of hyponatremia:
- high serum sodium level
, - confusion
- lethargy
- seizure
- coma due to cell shriveling
What physiologic and pathophysiologic conditions can lead to alterations in electrolyte
intake, absorption, distribution, or excretion? How do these differ between specific
electrolytes?
- General conditions that can lead to alterations in electrolyte intake and absorption include
altered composition of the diet, composition of intravenous fluids, and surgical removal of
portions of the gastrointestinal tract
- Potassium and phosphate are absorbed more easily from the gastrointestinal tract than are
calcium and magnesium
- Additional factors that alter calcium and magnesium absorption include medications and other
agents such as undigested fat in the intestines
- Absorption of calcium also is influenced by duodenal pH and by availability of vitamin D
- General conditions that alter electrolyte distribution and excretion include hormone disorders,
medications, the flow rate of renal tubular fluid, and the consistency and composition of feces
- Specific hormones and medications affect the distribution and excretion of different electrolytes
What are the characteristic clinical findings of plasma excesses and deficits of potassium,
calcium, magnesium, and phosphate ions?
Hyperkalemia --> hypopolarization
Hypokalemia --> hyperpolarization
Potassium imbalance:
- skeletal muscle weakness
- flaccid paralysis
CORRECT ANSWERS!!
What physiologic and pathophysiologic conditions predispose an individual to disturbances
in fluid intake?
- habit
- social factors
- thirst
- trauma, infection, neoplasia, surgery --> disruption in physiological signals of thirst
- altered level of consciousness
- inability to acquire or physically drink fluids
- increasing age; cerebral osmoreceptor-mediated thirst diminishes in older adults
additional routes for fluid intake:
- IV
- tube in GI tract and other body cavities
- subcutaneous tissue or bone marrow
- rectal intake
- lungs (drowning)
How do the compositions of plasma and interstitial fluids differ? How are they similar?
Different:
- Plasma contains many proteins whereas interstitial fluid contains few proteins
Similar:
- relatively rich in sodium, chloride, and bicarbonate ions
- relatively low in potassium, magnesium and phosphate ions
What regulates water and electrolyte movement between plasma and interstitial fluids?
Across cell membranes?
,Between plasma and interstitial fluids:
- Water and electrolytes move across capillary walls by filtration, which is the net result of
opposing hydrostatic and colloid osmotic pressures in the capillary and the interstitial fluid
Across cell membranes:
- Water moves in and out of cells by osmosis, which is driven by unequal particle concentrations
on the two sides of the semipermeable cell membrane
- Electrolytes move across cell membranes through membrane channels or ion pumps
What are the usual and pathologic routes of fluid exit from the body?
Usual:
- urinary tract
- bowels
- lungs
- skin
Pathologic:
- emesis (vomiting)
- tubes in GI tract or other body cavities
- hemorrhage
- drainage from fistulas, wounds, or open areas of the skin
- paracentesis (the perforation of a cavity of the body or of a cyst or similar outgrowth, especially
with a hollow needle to remove fluid or gas)
Under what conditions are extracellular volume deficit and excess likely to occur, and what
are the characteristic clinical findings?
Extracellular fluid volume (ECV) deficit is likely to occur when there is removal of a sodium-
containing fluid from the body, such as with excessive gastrointestinal or renal excretion, or
other losses such as hemorrhage
Clinical findings of ECV deficit:
- sudden weight loss
,- postural blood pressure with increased heart rate
- flat neck veins
- oliguria
ECV excess can occur with excessive intravenous infusion of sodium-containing isotonic fluids,
and with renal retention of sodium and water
Clinical findings of ECV excess:
- sudden weight gain
- edema
- manifestations of circulatory overload
Under what conditions are the hypernatremia (water excess) and hyponatremia (water
deficit) likely to occur, and what are the characteristic clinical findings?
Hypernatremia:
- excessive antidiuretic hormone secretion
- hypotonic fluid intake
Clinical findings of hypernatremia:
- low serum sodium concentration
- confusion
- lethargy
- seizure
- coma due to cell swelling
Hyponatremia:
- inadequate water intake
- excessive water excretion or loss
Clinical findings of hyponatremia:
- high serum sodium level
, - confusion
- lethargy
- seizure
- coma due to cell shriveling
What physiologic and pathophysiologic conditions can lead to alterations in electrolyte
intake, absorption, distribution, or excretion? How do these differ between specific
electrolytes?
- General conditions that can lead to alterations in electrolyte intake and absorption include
altered composition of the diet, composition of intravenous fluids, and surgical removal of
portions of the gastrointestinal tract
- Potassium and phosphate are absorbed more easily from the gastrointestinal tract than are
calcium and magnesium
- Additional factors that alter calcium and magnesium absorption include medications and other
agents such as undigested fat in the intestines
- Absorption of calcium also is influenced by duodenal pH and by availability of vitamin D
- General conditions that alter electrolyte distribution and excretion include hormone disorders,
medications, the flow rate of renal tubular fluid, and the consistency and composition of feces
- Specific hormones and medications affect the distribution and excretion of different electrolytes
What are the characteristic clinical findings of plasma excesses and deficits of potassium,
calcium, magnesium, and phosphate ions?
Hyperkalemia --> hypopolarization
Hypokalemia --> hyperpolarization
Potassium imbalance:
- skeletal muscle weakness
- flaccid paralysis
