Physio 31: Blood as a Circulatory Fluid & the Dynamics of Blood & Lymph Flow

The heart may generate pressure, but circulation depends on the properties of the fluid being moved and the vessels that carry it. Blood is not just a carrier—it is a living fluid whose behaviour shapes resistance, delivery, and exchange. Alongside it, lymph quietly maintains balance, returning what circulation leaves behind.In this episode, Medlock Holmes explores blood as a circulatory fluid and the principles governing blood and lymph flow. We examine viscosity, laminar versus turbulent flow, resistance, compliance, and how vessel structure determines distribution. Lymphatic flow is explored as a complementary system—slow, pressure-independent, and essential for volume regulation and immune surveillance.This episode reframes circulation as a dynamic partnership between force, fluid, and form.Here, physiology reminds us that movement is shaped as much by medium as by motive power.Key Takeaways* Blood flow depends on viscosity, vessel radius, and pressure gradients* Laminar flow enables efficient transport; turbulence disrupts delivery* Vascular resistance is a key determinant of circulation* Lymphatic flow supports fluid balance and immune function* Circulation reflects interaction between heart, vessels, and fluid This is a public episode. If you'd like to discuss this with other subscribers or get access to bonus episodes, visit drmanaankarray.substack.com/subscribe