What is the difference between the ECF and the ICF?
The intracellular fluid (ICF) compartment is the system that includes all fluid enclosed in cells by their plasma membranes. Extracellular fluid (ECF) surrounds all cells in the body.
How does fluid move between ECF and ICF?
When a hyposmotic fluid is lost from the ECF, the volume of the ECF decreases, and the osmolarity increases. When the osmolarity in the ECF rises compared to ICF, water moves by osmosis from the ICF into the ECF.
Is ECF volume higher than ICF?
Intracellular fluid (ICF) represents about two thirds of the TBW, which is equivalent to 30% to 40% of total body weight. However, the proportion of ECF is much greater than that of ICF in preterm infants and reaches 60% of TBW at term.
Is interstitial fluid and ECF the same?
The main component of the extracellular fluid (ECF) is the interstitial fluid, or tissue fluid, which surrounds the cells in the body. The other major component of the ECF is the intravascular fluid of the circulatory system called blood plasma. The remaining small percentage of ECF includes the transcellular fluid.
How do intracellular fluid differ from intracellular fluid?
The key difference between intracellular and interstitial fluid is that intracellular fluid is the fluid that is contained within cells, while interstitial fluid is the fluid between blood vessels and cells. Human body fluid can be conceptually divided into various fluid compartments.
Is fluid pressure inside the capillary greater or less than the pressure in the ECF?
Due to the pressure of the blood in the capillaries, blood hydrostatic pressure is greater than interstitial fluid hydrostatic pressure, promoting a net flow of fluid from the blood vessels into the interstitium.
How is fluid between interstitial and intracellular compartments distributed?
Additionally, there is a relationship between the interstitial fluid and intracellular fluid. These two environments very closely influence each other, as the membrane of the cell separates them. Generally, nutrients diffuse into the cell with waste products coming out into the interstitial space.
Which part of the capillary has the most hydrostatic pressure?
arteriolar end
Capillary Hydrostatic Pressure (PC ) This pressure drives fluid out of the capillary (i.e., filtration), and is highest at the arteriolar end of the capillary and lowest at the venular end.
How does extracellular fluid affect blood pressure?
In general, the elevation of extracellular fluid (ECF) increases the preload, which eventually contributes to the generation of hypertension. However, the volume of ECF in hypertension has been reported to be diverse (expanded, normal or reduced), and most results were from small-sized studies.
Is extracellular fluid hypotonic?
In a hypotonic solution, the extracellular fluid has a lower osmolarity than the fluid inside the cell; water enters the cell. In a hypertonic solution, the extracellular fluid has a higher osmolarity than the fluid inside the cell; water leaves the cell.
How do the compositions of ECF and ICF difference?
The composition of intracellular and extracellular fluid differs by the presence of high concentration of sodium ions and low concentration of potassium ions in the extracellular fluid.
What is interstitial fluid pressure?
Interstitial fluid pressure is determined by a complex interplay between the fluid influx (blood capillary filtration), the fluid outflow (lymph flow), and the compartment’s ability to expand (tissue compliance). 2. Interstitial fluid pressure is thus regulated locally at the tissue level.
Why is hydrostatic pressure low in the interstitial fluid?
In both tissues under normal perfusion, outflow capacities (venous blood and lymph) are greater than needed for the inflow volume and capillary permeability. Large outflow capacities drain most of the interstitial water and reduce its hydrostatic pressure to 0.
How does fluid move from interstitial to intracellular space?
A cell membrane or plasma membrane functions as a barrier and separates the intracellular compartment from the interstitial space. Water passes through this barrier readily, but small and large molecules do not pass through. Fluids are constantly moving across the capillary membrane, in and out of the cell.
Which fluid compartment contains the greatest fluid volume?
As shown in Figure 1-1, the largest volume of fluid in the body is inside cells. The intracellular fluid (ICF) compartment comprises approximately 40% of body weight (approximately two thirds of total body water).
What is the approximate percentage of fluid in the ECF and ICF fluid compartments?
The extracellular fluid comprises approximately 20% of total body weight and further subcategorizes as plasma at approximately 5% of body weight and interstitial space which is approximately 12% of body weight.
When ECF volume increases what happens?
Conversely, when the ECF volume is excessive, the body increases urinary sodium excretion and hopes that the individual will not eat incredible amounts of salt. In this way, the body can exert control of the total amont of sodium in the ECF by modulating urinary sodium excretion.