Hemorheology | EPFL Graph Search

Are you an EPFL student looking for a semester project?

Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.

Hemorheology, also spelled haemorheology (from Greek ‘αἷμα, haima 'blood' and rheology, from Greek ῥέω rhéō, 'flow' and -λoγία, -logia 'study of'), or blood rheology, is the study of flow properties of blood and its elements of plasma and cells. Proper tissue perfusion can occur only when blood's rheological properties are within certain levels. Alterations of these properties play significant roles in disease processes. Blood viscosity is determined by plasma viscosity, hematocrit (volume fraction of red blood cell, which constitute 99.9% of the cellular elements) and mechanical properties of red blood cells. Red blood cells have unique mechanical behavior, which can be discussed under the terms erythrocyte deformability and erythrocyte aggregation. Because of that, blood behaves as a non-Newtonian fluid. As such, the viscosity of blood varies with shear rate. Blood becomes less viscous at high shear rates like those experienced with increased flow such as during exercise or in peak-systole. Therefore, blood is a shear-thinning fluid. Contrarily, blood viscosity increases when shear rate goes down with increased vessel diameters or with low flow, such as downstream from an obstruction or in diastole. Blood viscosity also increases with increases in red cell aggregability. Blood viscosity is a measure of the resistance of blood to flow. It can also be described as the thickness and stickiness of blood. This biophysical property makes it a critical determinant of friction against the vessel walls, the rate of venous return, the work required for the heart to pump blood, and how much oxygen is transported to tissues and organs. These functions of the cardiovascular system are directly related to vascular resistance, preload, afterload, and perfusion, respectively. The primary determinants of blood viscosity are hematocrit, red blood cell deformability, red blood cell aggregation, and plasma viscosity. Plasma's viscosity is determined by water-content and macromolecular components, so these factors that affect blood viscosity are the plasma protein concentration and types of proteins in the plasma.

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related concepts (12)

Vascular resistance is the resistance that must be overcome to push blood through the circulatory system and create blood flow. The resistance offered by the systemic circulation is known as the systemic vascular resistance (SVR) or may sometimes be called by the older term total peripheral resistance (TPR), while the resistance offered by the pulmonary circulation is known as the pulmonary vascular resistance (PVR). Systemic vascular resistance is used in calculations of blood pressure, blood flow, and cardiac function.

Hemodynamics or haemodynamics are the dynamics of blood flow. The circulatory system is controlled by homeostatic mechanisms of autoregulation, just as hydraulic circuits are controlled by control systems. The hemodynamic response continuously monitors and adjusts to conditions in the body and its environment. Hemodynamics explains the physical laws that govern the flow of blood in the blood vessels.

Related courses (7)

ME-481: Biomechanics of the cardiovascular system

This lecture will cover anatomy and physiology of the cardiovascular system, biophysics of the blood, cardiac mechanics, hemodynamics and biomechanics of the arterial system, microcirculation and biom

CIVIL-708: UHPFRC for structures - Fundamentals & Properties

This course aims at giving students the fundamental knowledge necessary to design, model, and apply Ultra High Performance Fiber Reinforced Concretes (UHPFRC) in structures, in a sustainable way. It p

MSE-206: Rheology and fluid mechanics

Ce cours est une introduction à la rhéologie des solides viscoélastiques linéaires, aux phénomènes d'écoulements des fluides, et aux méthodes utilisées en rhéologie. Les fluides Newtoniens ou non, la

Related lectures (54)

Arterial Flow Modeling ME-484: Numerical methods in biomechanics

Covers arterial flow modeling, shear stress, boundary conditions, viscosity impact, and non-Newtonian blood flow.

Suspension Viscosity and Flow Regimes

Explores suspension viscosity, flow regimes, formulas by Einstein and G. I. Taylor, and experimental setups.

Polymer Viscoelasticity MSE-431: Physical chemistry of polymeric materials

Explores the viscoelastic behavior of polymeric materials, covering stress relaxation, mechanical models, molecular dynamics, and rheology concepts.