Tissue Fluid Formation

The medium in which cells are submerged is called tissue fluid. It is sometimes called interstitial fluid and forms 20% of ECF or extracellular fluid. Here, let us learn about the formation of tissue fluid in detail.

Table of Contents

Tissue Fluid Formation

The formation of tissue fluid comprises two major processes:

  1. Filtration
  2. Reabsorption

Filtration

Filtration is the primary mechanism by which tissue fluid is created.

  • In the arterial end of the capillary, the blood pressure or hydrostatic pressure is typically around 32 mm Hg. The filtration of water and other chemicals from the blood into tissue compartments is fueled by this hydrostatic pressure.
  • This pressure steadily decreases along the capillary’s length, peaking at 15 mm Hg at the venous end.
  • Large molecules, especially plasma proteins, cannot pass through the capillary membrane. As a result, these proteins continue to circulate in the blood and exert colloidal osmotic pressure of about 25 mm Hg.
  • The circulatory system’s colloidal osmotic pressure works against the filtration of water and other substances from capillary blood into the tissue space. However, the osmotic pressure is less than the hydrostatic pressure (32 mm Hg) in the artery end of the capillary.

Reabsorption

  • The fluid that was filtered at the arterial end is returned to circulation at the venous end of the capillaries. The pressure gradient is crucial in this situation as well.
  • The hydrostatic pressure is lower (15 mm Hg) and the oncotic or colloidal osmotic pressure is much higher (25 mm Hg) near the venous end of capillaries.
  • The fluid is reabsorbed into the capillaries together with waste products from the tissue fluid because of the pressure differential of 10 mm Hg. The lymphatic veins receive about 10% of the filtered fluid.

As a result, the filtration process at the capillaries’ arterial end aids in the creation of tissue fluids, while the reabsorption process at the capillaries’ venous end aids in maintaining the volume of tissue fluid.

Also Check:What is Plasma in Blood?

Factors that influence the formation of tissue fluid

The three factors that influence the quantity of tissue fluid formed are:

  1. Capillary permeability.
  2. The pressure difference between tissue fluid and the capillary.
  3. The difference between colloidal osmotic pressure in the tissue fluid and blood.

Significance of Tissue Fluid

Blood and cells are not in direct touch because of the capillary membrane. Additionally, tissue fluid serves as a conduit for the exchange of different chemicals between the blood and cells in the capillary loop.

From the artery end of the capillary, oxygen and nutrients flow through the tissue fluid and enter the cells. Also through this fluid, carbon dioxide and other waste products diffuse from the cells into the capillary’s venous end.

Keep exploring BYJU’S Biology to learn more such exciting topics.

See more:

Recommended Video:

Frequently Asked Questions

Q1

How are the tissue fluids formed?

A process of filtration and reabsorption creates tissue fluid from blood plasma. This fluid fills the intracellular space and serves as a passage for the movement of gases, metabolic waste products and nutrients between lymph, tissue cells and blood capillaries.
Q2

What is colloidal osmotic pressure?

Colloidal osmotic pressure, also known as oncotic pressure, is a type of osmotic pressure brought on by the plasma proteins in blood vessels that force fluid back into the capillaries.
Q3

What is hydrostatic pressure?

Hydrostatic pressure is the force produced by any liquid when it is contained. A common example of hydrostatic force in daily life is the pressure that blood exerts on the walls of blood vessels.
Q4

What is oedema?

Oedema is characterised as swelling brought on by an excessive buildup of fluid in the tissues. The buildup of fluid inside the cell is called intracellular oedema and it is caused by poor metabolism and malnutrition. The accumulation of fluid outside the cell is known as extracellular oedema. It mainly results from aberrant fluid leakage into the interstitial space from capillaries.