McCance 8th ed Ch.3 The Cellular Environment:
Fluids and Electrolytes, Acids and Bases Exam
Study Questions Answered Correctly
Intracellular fluid (ICF) - Answer fluid within cells comprises 2/3 of the body's water content
extracellular fluid (ECF) - Answer body fluids located outside of cells. Remaining 1/3 of body's water
content.
2 main ECF:
1. Interstitial Fluid
2. Intravascular fluid (plasma)
Other ECF:
Lymph
Transcellular fluid
Total Body Water (TBW) - Answer The sum of fluids within all body compartments; 60% of body weight
Infant: 70-80%
Child: 60-65%
TBW decreases with age and as fat content increases
Water movement - Answer water moves between ICF And ECF compartments through osmosis
Moves freely through the lipid bilayer cell membrane and through aquaporins
Osmolality of TBW is normally at equilibrium
,Sodium is responsible for osmotic balance of the ECF space
Potassium maintains the osmolotic balance of the ICF space.
Aquaporins - Answer channel proteins that facilitate the passage of water
Water movement between plasma and interstitial fluid - Answer distribution of water and the
movement of nutrients and waste products between the plasma in the tissue capillaries and interstitial
space occur as a result of changes in hydrostatic pressure and osmotic forces at the arterial and venous
ends of the capillary.
plasma proteins maintain the effective osmolality, do not cross the capillary membrane, and generate
plasma oncotic pressure.
Albumin is the plasma protein primary responsible for plasma oncotic pressure.
Osmotic forces within the capillary are balanced by hydrostatic pressure which is primarily determined
by blood pressure and blood volume.
4 forces determine filtration vs reabsorption in the capillary:
1. capillary hydrostatic pressure (blood pressure)
2. Capillary oncotic pressure
3. Interstitial hypdrostatic pressure
4. Interstitial oncotic pressure
Capillary hydrostatic pressure (blood pressure) - Answer facilitates the outward movement of water
from the capillary to the interstitial space
capillary oncotic pressure - Answer osmotically attracts water from the interstitial space back into the
capillary
, interstitial hydrostatic pressure - Answer facilitates the inward movement of water from the interstitial
space into the capillary
interstitial oncotic pressure - Answer osmotically attracts water from the capillary into the interstitial
space
Starling hypothesis - Answer Net filtration = forces favoring filtration - forces opposing filtration
Forces favoring filtration=Capillary hydrostatic pressure and interstitial oncotic pressure
Forces opposing filtration=Capillary oncotic pressure and interstitial hydrostatic pressure
net filtration - Answer the movement of fluid back and forth across the capillary wall
Alteration in water movement: EDEMA - Answer DEFINITION: excessive accumulation of fluid within the
interstitial spaces.
PATHOLOGICAL PROCESS: related to an increase
in the forces favoring fluid filtration from the
capillaries or the lymphatic channels into
tissue.
4 most common mechanisms:
1. Increased capillary hydrostatic pressure
2. Decreased capillary oncotic pressure
3. Increased capillary membrane permeability
4. Lymphatic obstruction
PATHOPHYSIOLOGY:
1. Increased capillary hydrostatic pressure
Fluids and Electrolytes, Acids and Bases Exam
Study Questions Answered Correctly
Intracellular fluid (ICF) - Answer fluid within cells comprises 2/3 of the body's water content
extracellular fluid (ECF) - Answer body fluids located outside of cells. Remaining 1/3 of body's water
content.
2 main ECF:
1. Interstitial Fluid
2. Intravascular fluid (plasma)
Other ECF:
Lymph
Transcellular fluid
Total Body Water (TBW) - Answer The sum of fluids within all body compartments; 60% of body weight
Infant: 70-80%
Child: 60-65%
TBW decreases with age and as fat content increases
Water movement - Answer water moves between ICF And ECF compartments through osmosis
Moves freely through the lipid bilayer cell membrane and through aquaporins
Osmolality of TBW is normally at equilibrium
,Sodium is responsible for osmotic balance of the ECF space
Potassium maintains the osmolotic balance of the ICF space.
Aquaporins - Answer channel proteins that facilitate the passage of water
Water movement between plasma and interstitial fluid - Answer distribution of water and the
movement of nutrients and waste products between the plasma in the tissue capillaries and interstitial
space occur as a result of changes in hydrostatic pressure and osmotic forces at the arterial and venous
ends of the capillary.
plasma proteins maintain the effective osmolality, do not cross the capillary membrane, and generate
plasma oncotic pressure.
Albumin is the plasma protein primary responsible for plasma oncotic pressure.
Osmotic forces within the capillary are balanced by hydrostatic pressure which is primarily determined
by blood pressure and blood volume.
4 forces determine filtration vs reabsorption in the capillary:
1. capillary hydrostatic pressure (blood pressure)
2. Capillary oncotic pressure
3. Interstitial hypdrostatic pressure
4. Interstitial oncotic pressure
Capillary hydrostatic pressure (blood pressure) - Answer facilitates the outward movement of water
from the capillary to the interstitial space
capillary oncotic pressure - Answer osmotically attracts water from the interstitial space back into the
capillary
, interstitial hydrostatic pressure - Answer facilitates the inward movement of water from the interstitial
space into the capillary
interstitial oncotic pressure - Answer osmotically attracts water from the capillary into the interstitial
space
Starling hypothesis - Answer Net filtration = forces favoring filtration - forces opposing filtration
Forces favoring filtration=Capillary hydrostatic pressure and interstitial oncotic pressure
Forces opposing filtration=Capillary oncotic pressure and interstitial hydrostatic pressure
net filtration - Answer the movement of fluid back and forth across the capillary wall
Alteration in water movement: EDEMA - Answer DEFINITION: excessive accumulation of fluid within the
interstitial spaces.
PATHOLOGICAL PROCESS: related to an increase
in the forces favoring fluid filtration from the
capillaries or the lymphatic channels into
tissue.
4 most common mechanisms:
1. Increased capillary hydrostatic pressure
2. Decreased capillary oncotic pressure
3. Increased capillary membrane permeability
4. Lymphatic obstruction
PATHOPHYSIOLOGY:
1. Increased capillary hydrostatic pressure
