👉 Fluid, particularly blood, presents several challenges due to its unique properties and the dynamic environment in which it operates. One major challenge is maintaining proper viscosity, which ensures efficient circulation and prevents clotting or excessive resistance in blood vessels. Another issue is the need for fluidity to navigate through narrow capillaries and avoid mechanical damage, requiring a balance between flexibility and structural integrity. Additionally, fluid must efficiently transport oxygen, nutrients, and waste products while dealing with varying temperatures, pH levels, and the presence of various substances like proteins and cells. These factors collectively make fluid dynamics a complex and critical aspect of biological systems, requiring precise regulation to ensure optimal physiological function.