👉 Fluid, in the context of biology and physiology, refers to any substance that exists in a liquid state within living organisms. This includes blood, which is a vital fluid composed primarily of water, red blood cells, white blood cells, platelets, and various proteins, electrolytes, and gases. Blood circulates throughout the body via the cardiovascular system, transporting oxygen, nutrients, hormones, and waste products between different tissues and organs. Other examples of bodily fluids include synovial fluid that lubricates joints, mucus that protects mucous membranes and traps particles in the respiratory and digestive tracts, and cerebrospinal fluid that cushions the brain and spinal cord. These fluids play crucial roles in maintaining homeostasis, facilitating cellular functions, and protecting the body from damage.
