Rheological Properties of blood

Rheology is the study of the flow of matter, primarily in a liquid state, but also as "soft solids" or solids under conditions in which they respond with the plastic flow rather than deforming elastically in response to an applied force. Rheology is the science of deformation and flows within a material.

1. BIOMECHANICS
Rheology of
Blood
Prepared By Atheena Pandian

2. Today's Presentation
POINTS OF DISCUSSION
What is Rheology?
Properties
Density
Viscocity
Osmotic Pressure
Oncotic Pressure
1.
2.
3.
4.
5.
6.

3. The branch of physics that deals with the
deformation and flow of matter, especially the
non-Newtonian flow of liquids and the plastic
flow of solids.
What is Rheology?

4. Rheology

Rheology is defined as the study of flow behavior. It is normally
applied to fluid materials (or materials that exhibit a time-
dependent response to stress).

Flow is typically measured using shear and the shear parameters
of stress (τ) and strain rate ( ) are calculated from measurements
of torque and flow rate.

5. Meaning of Rheological
Properties

The material properties that govern the specific way in which
these deformation or flow behaviors occur are
called rheological properties.

6. Fluidity of blood is strongly influenced by
flow conditions. More specifically, ηb
depends on shear rate, decreasing with
increased shear rate.

This property is known as shear-thinning
and is characteristic of a non-Newtonian
fluid.
BLOOD VISCOSITY (ΗB)

7. 1. DENSITY OR SPECIFIC GRAVITY
Factors affecting the Blood
Flow
2. VISCOCITY
3. PRESSURE

Osmotic Pressure
Oncotic Pressure
1.
2.

8. Density of Blood

Density is a measure of mass per volume. The average density of an
object equals its total mass divided by its total volume.

The density of blood plasma is approximately 1025 kg/m3 and

the density of blood cells circulating in the blood is approximately 1125
kg/m3.

Blood plasma and its contents is known as whole blood.

The average density of whole blood for a human is about 1060 kg/M3.
Blood density changes with body posture.

9. Viscosity
The state of being thick, sticky, and semi-fluid in
consistency, due to internal friction."cooling the fluid raises
its viscosity

In pascal-seconds (Pa·s), the viscosity of blood at 37 °C is
normally 3 × 10−3 to 4 × 10−3, respectively 3 - 4 centipoise
(cP) in the centimetre gram second system of units.

10. Osmotic
Oncotic
Blood Pressure

Blood pressure is the pressure of circulating blood on the walls of
blood vessels.

Rheology Pressure of Blood

1.
2.

11. Osmotic Pressure
The pressure that would have to be
applied to a pure solvent to prevent it
from passing into a given solution by
osmosis, often used to express the
concentration of the solution

12. FORMULA FOR CALCULATION OSMOTIC PRESSURE

13. Range of Osmotic Pressure in Blood
Osmotic Pressure of the blood
that has values approximating
300 mOsm /L

14. Oncotic pressure
Oncotic pressure, or colloid osmotic pressure, is a
form of osmotic pressure exerted by proteins,
notably albumin, in a blood vessel's plasma
(blood/liquid) that usually tends to pull water into the
circulatory system

It is the opposing force to hydrostatic pressure.

15. Oncotic pressure
values are
approximately 290
mOsm per kg of
water
Oncotic pressure

16. Thank You