UNDERSTANDING PATHOPHYSIOLOGY
UPDATED COMPLETE QUESTIONS AND
ANSWERS VERIFIED PREPARATION
RESOURCE
●● Intracellular fluid
Answer: all the fluid within cells, about 2/3 of TBW
●● Extracellular fluid (ECF)
Answer: all the fluid outside the cells (about 1/3 of TBW)
●● What are the two main compartments of extracellular fluid?
Answer: interstitial fluid (the space between cells and outside the blood
vessels) and intravascular fluid (blood plasma)
●● Other ECF compartments are there?
Answer: lymph and transcellular fluids (synovial, intestinal, cerebral
spinal, sweat, urine, pleural, peritoneal, pericardial and intraocular)
●● Why do people with more body fat have proportionately less TBW
and tend to be more susceptible to dehydration?
Answer: Fat is hydrophobic and very little water is contained in adipose
cells
,●● How is fluid distribution maintained?
Answer: hydrostatic pressure (pushes water) and osmotic pressure (pulls
water)
●● What is an average infants TBW?
Answer: 75%
●● What is an average adult male's TBW?
Answer: 60%
●● What is an average adult female's TBW?
Answer: 50%
●● What is an average older adult's TBW?
Answer: 45-55%
●● Why do the elderly have lower TBW?
Answer: decreased muscle mass
increased fat%
decreased ability to regulate fluid levels (thrist and renal function)
, ●● What are the primary sources of body water?
Answer: water obtained by drinking, ingested in food and derived from
oxidative metabolism
●● Normally, the largest amounts of water are lost through...
Answer: renal excretion, with lesser amounts lost through stool and
through vaporization from the skin and lungs
●● Symptoms of dehydration in newborn infants include:
Answer: increased thirst, decreased urine output, decreased body weight,
decreased skin elasticity, sunken fontanels, absent tears, dry mucous
membranes, increased heart rate and irritability
●● Which plasma protein doesn't move across the capillary membrane
and is responsible for generating plasma oncotic pressure?
Answer: Albumin
●● As plasma flow from the arterial to the venous end of the capillary,
which four forces determine if fluid moves out of the capillary and into
the interstitial space (filtration) or if fluid moves back into the capillary
from the interstitial space (reabsorption)?
Answer: 1. Capillary hydrostatic pressure (blood pressure)
2. Capillary (plasma) oncotic pressure
3. Interstitial hydrostatic pressure
UPDATED COMPLETE QUESTIONS AND
ANSWERS VERIFIED PREPARATION
RESOURCE
●● Intracellular fluid
Answer: all the fluid within cells, about 2/3 of TBW
●● Extracellular fluid (ECF)
Answer: all the fluid outside the cells (about 1/3 of TBW)
●● What are the two main compartments of extracellular fluid?
Answer: interstitial fluid (the space between cells and outside the blood
vessels) and intravascular fluid (blood plasma)
●● Other ECF compartments are there?
Answer: lymph and transcellular fluids (synovial, intestinal, cerebral
spinal, sweat, urine, pleural, peritoneal, pericardial and intraocular)
●● Why do people with more body fat have proportionately less TBW
and tend to be more susceptible to dehydration?
Answer: Fat is hydrophobic and very little water is contained in adipose
cells
,●● How is fluid distribution maintained?
Answer: hydrostatic pressure (pushes water) and osmotic pressure (pulls
water)
●● What is an average infants TBW?
Answer: 75%
●● What is an average adult male's TBW?
Answer: 60%
●● What is an average adult female's TBW?
Answer: 50%
●● What is an average older adult's TBW?
Answer: 45-55%
●● Why do the elderly have lower TBW?
Answer: decreased muscle mass
increased fat%
decreased ability to regulate fluid levels (thrist and renal function)
, ●● What are the primary sources of body water?
Answer: water obtained by drinking, ingested in food and derived from
oxidative metabolism
●● Normally, the largest amounts of water are lost through...
Answer: renal excretion, with lesser amounts lost through stool and
through vaporization from the skin and lungs
●● Symptoms of dehydration in newborn infants include:
Answer: increased thirst, decreased urine output, decreased body weight,
decreased skin elasticity, sunken fontanels, absent tears, dry mucous
membranes, increased heart rate and irritability
●● Which plasma protein doesn't move across the capillary membrane
and is responsible for generating plasma oncotic pressure?
Answer: Albumin
●● As plasma flow from the arterial to the venous end of the capillary,
which four forces determine if fluid moves out of the capillary and into
the interstitial space (filtration) or if fluid moves back into the capillary
from the interstitial space (reabsorption)?
Answer: 1. Capillary hydrostatic pressure (blood pressure)
2. Capillary (plasma) oncotic pressure
3. Interstitial hydrostatic pressure
