„Secret fluids” - biological fluidsoverview, modelling, problems

Anna Kucaba-PiętalRzeszów University of Technology,

Poland

School of Engineering, University of Liverpool Liverpool L69 3GH, UK , May 13th 2013

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Overview of biological fluids, contents, modelling, problem formulation• Fundamental

• biofluid• rheology

• Blood • rheological parameters of blood• factors which effect on blood viscosity• diaseses

• Synovial fluid • rheological parameters of s.f• factors which effect on s. f. viscosity• diaseses

• Plasma and lymph as Newtonian fluid• Conclusion

Contents

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Questions:What influences the change of rheological propertiesof biological fluids and what are the consequences?

Why is it important to predict rheologicalparameters of biofluid?

Answers:Due to the formulation bioflow equations

To maintain nonbiological fluids that hasrheological properties comparble to real biofluid

To use it in diagnostics of clinical disorders

Aim of Lectures

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• Total amount of fluid in the human body is approximately 70% of body weight

• Body fluid has been divided into two compartments – – Intracellular fluid (ICF)

• Inside the cells• 55% of total body water

– Extracellular fluid • Outside the cells• 45% of total body water

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1Body Fluids

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Intracellular

Extracellular

Interstitial

Plasma

Body fluids

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Extracellular fluid includes: • Interstitial fluid

» Present between the cells » Approximately 80% of ECF

• Plasma » Present in blood » Approximately 20% of ECF

• Also includes » Lymph » synovial fluid » aqueous humor » cerebrospinal fluid» vitreous body » endolymph » perilymph » pleural, pericardial and peritoneal fluids

Body fluid compartments

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Body fluid compartments

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Body fluid compartments

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• Plasma membrane • Separates ICF from surrounding interstitial fluid

• Blood vessel wall • Separate interstitial fluid from plasma

Barriers separate ICF, interstitial fluid and plasma

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Organic substances Glucose Amino acids Fatty acids Hormones Enzymes

Inorganic substances Sodium Potassium Calcium Magnesium Chloride Phophate Sulphate

Composition of body fluids

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• Most abundant cation - Na+,– muscle contraction – Impulse transmission– fluid and electrolyte balance

• Most abundant anion - Cl- – Regulates osmotic pressure– Forms HCl in gastric acid

• Most abundant cation - K+

– Resting membrane potential– Action potentials – Maintains intracellular volume– Regulation of pH

• Anion are proteins and phosphates (HPO4

2-)

Na+ /K+ pumps play major role in keeping K+ high inside cells and Na+ high outside cell

Difference

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• In health the volume and composition of various body fluid compartments are maintained within physiological limits even in face of wide variations in intake of water and solutes .

Control of body fluid volume (Homeostasis)

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• Amniotic fluid• Aqueous humour and vitreous humour• Bile• Blood • Breast milk• Cerebrospinal fluid• Cerumen (earwax)• Chyle• Chyme• Endolymph and perilymph• Feces - see diarrhea• Female ejaculate• Gastric acid• Gastric juice• Lymph

• Mucus (including nasal drainage and phlegm)

• Pericardial fluid• Peritoneal fluid• Pleural fluid• Pus• Rheum• Saliva• Sebum (skin oil)• Semen• Sputum• Sweat• Synovial fluid• Tears• Vaginal secretion• Vomit• Urine

Body fluids

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• Lymph• Milk• Cerebrospinal fluid• Amniotic fluid• Aqueous humor• Sweat• Tears

Specialized fluids of the body

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Microscopic level• Transport Mechanisms• Membrane Transport• Intracellular membrane

transport• ICF-ECF Exchange• ISF-Plasma Exchange• Capillary Pressures

Macroscopic level• Blood Flow CFD simulation • synovial fluid

Transport problems

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• Wstawie pozniej

Navier-Stokes equations

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• The viscosity and elasticity determine the pressure required to produce bioflows.

• Viscosity is an assessment of the rate of energy dissipation

• Elasticity is an assessment of the elastic storage of energy

• How is relations between shear stress and deformation?

Rheological parameters, a constitutive equation

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Body fluid percentages

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Rheology(of Liquids)

PhysicsChemistry

Mechanics of

Continuum

Technology/Engineering

Rheology as an interdisciplinary science

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dUτ μ μγ

dy

Viscosity = F(S,T,p,s,t, V)

S- physico-chemical properties of substances,T-temperature, p- pressure, s-velocity of shear, t-time, V-voltage

Viscosity

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NEWTONIANFLUID

NON-NEWTONIANFLUID

F

y u(y)

= t f( )g.

Models

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Blood is a concentrated suspension of Red Blood Cells; outside the range of dilute suspension

Particles change their shape in response to the fluid forces

The nature of RBC membrane and its deformation stress/strain is much less established

RBC tends to form agregates known as rouleaux

Blood

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Constituents of Blood % Plasma proteins 3.2 – 4.4Red blood cells 40 – 54White blood cells 0.03 - 0.05Water 42 –58Electrolytes < 0.001Organic nutrients < 0.001Organic wastes < 0.001Platelets ~ 0.1

Blood - components

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TYPES OF LEUKOCYTES

RBCs

PLATELETS

Blood – formed elements

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RANGE

Density (g/cm3) 1.050-1.064

Viscosity (cP) 2.18-3.59

pH 7.35-7.45

Factors affecting the blood rheology:

a) hematocritb) deformation and agregation of red blood cellsc) biochemical properties of plasmad) temperaturee) the geometry and flow parameters

Physical properties of blood

PROPERTY

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Plasma is the straw-colored liquid in which the blood cells are suspended.

Composition of blood plasma:

Component PercentWater ~92Proteins 6–8Salts 0.8Lipids 0.6Glucose (blood sugar) 0.1

Plasma

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• Water : 90%• Solids: 10%• organic constituents: proteins, lipids,

carbohydrates , hormones, enzymes,Ketone bodies , and other organic compounds.Inorganic compounds: Na, K Ca,Cl,and CO2.

Plasma

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Comparison of Newtonian plasma and blood viscosity

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• Clear and colorless fluid• 96% water and 4% solids• Solids –

– Proteins • 2-6% of solids• albumin, globulin, fibrinogen, prothrombin, clotting factors, antibodies,

enzymes– Lipids

• 5-15% • Chylomicrons• Lipoproteins

– Carbohydrates• Glucose mainly

– NPN• Urea and creatinine

– Electrolytes• Sodium, calcium, potassium, chloride, bicarbonates

Lymph

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• Return protein from tissue spaces into blood• Redistribution of fluid• Removal of bacteria, toxins and other foreign bodies from

tissues• Maintain structural and functional integrity of tissue• Route for intestinal fat absorption• Transport lymphocytes

Functions of lymph

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• What is it? It is a fluid that resembles plasma but with a much lower concentration of suspended proteins

• Functions? Transports hormones, nutrients, and waste products

from peripheral tissues to the general circulationReturns fluid and solute from peripheral tissues to the

bloodMaintains blood volume and eliminates local variations

in the composition of the interstitial fluid

Lymphatic fluid

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Newtonian fluid: constant viscosity at all shear rates at a constant pressure and temperature. Relationship between shear stress and shear rate is linear.

Newtonian behavior

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Synovial fluid

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Contents value

Dry matter 0,133,5

Density(20oC) 1,00811,015

pH 7,27,4

viscosity (20oC)

water, g/kg 960988

hyaluronic acid(HA )

2-3%

The content of dry matter g/kg1240

Albumins, globulins g/lPhospholipids,glycoprotein's

10,721,310,20,5

Mucyns, g/l 0,681,35

Glucoses, g/l jak w surowicy krwi

Urynial Acid, mg/l

73,4

Synovial fluid

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• Minimise the friction between during bones movement or weight bearing

• Provides nutrition for cartilage.• 0.15-3.5ml

Functions

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Sodium Hyaluronate, Hyaluronan• Made up of repeating glucuronic acid and N-acetylglucosamine subunits• High molecular weight: 0.2 to 10 million Dalton• Major component of synovial fluid• Exhibits viscoelastic properties

Main Factors affecting the rheological properties:a) Hyaluronic Acid concentationc) Molecular weigh of Hyaluronic Acidd) Temperature

Synovial fluid

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• Pathophysiological significance of biofluid rheology

• Develop an understanding of how the micro- and nano-structure of blood influences its rheology

• Explore to use of rheological parameters in diagnostics and menagement of clinical disorders and inoptimisation of blood processing

• Explore new methods of measurement suited for clinical application

• Maintain new type apparatus for such measurements

Perspectives

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Thank you

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