What is Interstitial Fluid?-Composition and Functions

Interstitial fluid (also known as lymphatic fluid) is a clear liquid that surrounds cells and organs throughout the body. It helps regulate temperature and transport nutrients and waste from tissues to bloodstream. It consists of the following substances;

• Water
• Amino acids
• Sugars
• Fatty acids
• Coenzymes
• Hormones
• Neurotransmitter
• Salts
• Cellular products

In blood vessels, The fluid present in the space around the capillaries and tissues is called Interstitial fluid. There is the pressure of blood within the capillaries. This pressure causes leakage of fluid from the blood plasma. This fluid is collected into the spaces around the capillaries and tissues. This fluid is known as interstitial fluid.

It has been observed that interstitial fluid is also secreted by the sweat glands and the tears glands. In the skin, the interstitial fluid collects between the dermal cells and forms a thin layer of fluid which is called the Epidermis.

The Epidermis is composed of keratinocytes, Langerhans cells, melanocytes, fibroblasts, Merkel cells, and sebaceous glands. Skin is an important organ in the human body and protects us from various external damages. Skin provides a barrier to the entry of harmful substances and microorganisms into the body.

Composition Of Interstitial Fluid

The interstitial fluid is primarily composed of water, with dissolved nutrients, hormones, gases, wastes, and small proteins. Large proteins, red blood cells, and platelets cannot pass through the capillary wall. So they remain within the capillaries. But some white blood cells can come out through the intercellular spaces in the wall of the capillaries.

Blood flow to the skin is controlled by a network of small arteries and veins that supply blood to the skin and lymph vessels that return blood and lymph to the circulatory system. The capillaries in the skin are open at both ends and connect with each other and with the surrounding dermis, or skin. Several factors control blood flow in the skin. Blood pressure is one of these factors.

Function Of Interstitial Fluid

The function of interstitial fluid is the medium through which the exchange of materials takes place between the blood and nearby cells.

It is a dynamic fluid, subject to continuous renewal by filtration at the glomerulus in the kidney, and absorption from the blood at the capillaries and other sites. Interstitial fluid is the principal site of action of many hormones, neurotransmitters, and drugs.

Interstitial fluid also serves as a medium for the diffusion of nutrients and wastes between the blood and the cells. Interstitial fluid is the medium through which the exchange of materials takes place between the blood and nearby cells.