👉 The term "fluid" in a biological context refers to substances that can move freely within living organisms, unlike solids or gases that have more restricted movement. There are several types of fluids in the body, including blood, lymph, cerebrospinal fluid (CSF), synovial fluid, pleural fluid, and pericardial fluid. Blood is a complex fluid composed of plasma (the liquid component) and cells like red blood cells, white blood cells, and platelets, playing a vital role in transporting oxygen, nutrients, hormones, and waste products. Lymph is a clear fluid that circulates through the lymphatic system, aiding in immune responses and fluid balance. CSF surrounds the brain and spinal cord, cushioning them and removing waste products. Pleural fluid lubricates the surfaces of the lungs during breathing, while pericardial fluid reduces friction between the heart and surrounding tissues. Each type of fluid has unique properties and functions essential for maintaining homeostasis and overall health.
