👉 The outer fluid, often referred to as the fluid envelope or outer plasma in certain contexts, is a thin, gaseous layer that surrounds and separates cells from their immediate environment. This fluid is composed primarily of ions and small molecules, creating a semi-permeable barrier that facilitates the exchange of substances between cells and their surroundings. It plays a crucial role in maintaining cellular homeostasis, enabling processes such as nutrient uptake, waste removal, and communication between cells through signaling molecules. The outer fluid's composition and properties can vary depending on the specific tissue or organ, but it generally serves to protect and support cellular functions.
