BME211 Week 2

Function of the Cardiovascular System

Transports oxygen, nutrients, and waste throughout the body and maintains blood circulation.

Pulmonary Circulation

Carries deoxygenated blood from the heart to the lungs and back.

Systemic Circulation

Carries oxygenated blood from the heart to the rest of the body and returns deoxygenated blood.

Stress

Force applied per unit area.

Strain

Deformation or change in shape in response to stress.

1D Deformation

Deformation in a single dimension, such as stretching or compressing along one axis.

Stress-Strain Curve

Shows the relationship between stress and strain; includes elastic region, yield point, plastic region, and failure point.

Viscoelastic Behavior

Materials that exhibit both elastic (spring-like) and viscous (fluid-like) properties, such as biological tissues.

Compact Bone

Dense and strong, supports and protects.

Spongy Bone

Porous and lightweight, found at bone ends, helps absorb impact.

Elastic Arteries

Large, elastic fibers, absorb pressure from heartbeats.

Muscular Arteries

Distribute blood, control flow with smooth muscle.

Arterioles

Small, regulate blood flow into capillaries.

Hydrostatic Pressure

Pressure exerted by a fluid due to gravity.

Hydrostatic Pressure Equation

\( P = \rho g h \) (where \( \rho \) = fluid density, \( g \) = gravity, \( h \) = height).

Viscosity

Measure of a fluid’s resistance to flow.

Shear Rate

Rate at which layers of fluid move past each other.

Newtonian Fluid

Constant viscosity, regardless of stress (e.g., water).

Non-Newtonian Fluid

Viscosity changes with stress (e.g., blood).

Poiseuille’s Equation

Describes laminar flow of fluids in a tube; dependent on tube radius, length, and fluid viscosity.

Reynolds Number

Predicts flow type (laminar vs. turbulent).

Reynolds Number Equation

\( Re = \frac{\rho v D}{\mu} \) (where \( \rho \) = density, \( v \) = velocity, \( D \) = diameter, \( \mu \) = viscosity).

Blood Function

Transports oxygen, nutrients, and waste; flow is regulated by heart and vessel dynamics.

Constituents of Blood

Red blood cells, white blood cells, platelets, and plasma, each serving specific functions like oxygen transport and immune response.

Viscous Behavior of Blood

Blood behaves as a non-Newtonian fluid due to red blood cell interactions, altering flow characteristics.

Vortex Formation

Abnormal blood flow patterns, like vortices, can occur in diseased arteries, leading to plaque formation and increased disease risk.