👉 The stack fluid, also known as the interstitial fluid, is a critical component of the body's circulatory system, functioning as a medium that facilitates the exchange of nutrients, gases, and waste products between the bloodstream and various tissues. It resides within the spaces between cells (interstitial spaces) and blood vessels, acting as a bridge that connects the vascular system to the cellular environment. This fluid plays a vital role in maintaining homeostasis by transporting oxygen, glucose, and other essential molecules to cells while also removing metabolic waste products like carbon dioxide and urea. The composition of stack fluid closely mirrors that of plasma, ensuring efficient and effective cellular function throughout the body.