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Foreword

Foreword.  In the course of three months - our staff will guide you through the secrets of Me- - dical Biophysics Both lectures , and practicals are obligatory for students.  You will attend Lectures and Practicals according to timetable (your questions

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Foreword

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  1. Foreword  In the course of three months - our staff will guide you through the secrets of Me- - dical Biophysics Both lectures, and practicals are obligatory for students.  You will attend Lectures and Practicals according to timetable (your questions e.g. how to get credit, substitution in the case of illness, etc. are discussed with teachers during Practical sessions ) For Instructions to organization of study and details ask following teachers: Prof. Jakuš - head, Dr. Simera-vicehead Dr Poliacek-Assoc.Prof

  2. Content of study Coversfollowingtopics.:BiophysicsofCell, Transport membranemechanisms, Resting and Actionpotentials , Musclecontraction, Synapse, Basicsofrespiration, Heart and circulatorysys-ems, Senses, Hearing, Vision. Changes in body due to actionofmechanicalanelectromagneticinfluences, EffectsofSound, Infrared and Ultravio-letradiations, Radioactivity, Diagnosticmethods in humanmedicine: X-ray, Utrasound, Computertomography, Magnetictomography, etc. Therapy in humanmedicine, Biocybernetics, ModernMachines, Nanotechnology and manyothers. For more detailslookfor my Lecturesbeingavailable to see and downloadfromourfacultyhomepage: www.jfmed.uniba.sk/index.php?id=3649

  3. Study Literature - Source 1.Lectures– thecontentresultsfromProfessorsexperience, alsofromTextbookofMedicalBiophysics (in Slovak ), alsofromGanong´sTextbookofPhysiology ContentofsomeLectures and Practicals ,ProgrammeofLectures, Requirements and conditionhow to obtaincredits, pointsetc. are available on web.page: www.jfmed.uniba.sk/index.php?id=3649 2.Textbooks- Nave&Nave: PhysicsforHealth Sciences,1985, Ronto,Tarjanetal.:Anintroduction to BiophysicswithMedicalOrientation, 1999, 3. Booklet-Kukurovaetal.:BiophysicalElixir, 1991 4. WorksheetforPracticalsJakus,Poliacek, Simera :PracticalTasks in MedicalBiophysics ,2013 , itcontainstheory and personalprotocol to particulartasks.

  4. Medical Biophysics. Biophysics of a Cell. Transport membrane mechanisms. Resting membrane potential. LECTURE 1 JánJakuš (www.jfmed.uniba.sk/index.php?id=3649) Martin 2014

  5. Medical Biophysics is an interdisciplinary subject of medical scien-ces,explaining basic problems of a human body at a level of atoms, molecules, cells, tissues, and organs answers the physical problems that appear in biology, chemistry, anatomy, physiology... explains effects of radiation, giving rules and recommendations for their use and safety explains and creates new methods and devices for diagnosis and treatment of human diseases

  6. Medical Biophysics - kind of Medicine Science, a part of Biophysics

  7. HUMAN CELL Definition: Cellis a basicanatomical and functionalunitofthe body withtotalnumberof 60.000 bilions and sizefrom 4-120 µm (10-6 m). Numberofcellscomposestissues(206 bones ,600 muscles, thousandsofnerves), numberoftissuesbuildsorgans (heart, lungs, kidney.. ) Typicalsignsoflivingcell: ownmeta-bolism, excitability, reproduction Composition: Cytoskeleton -surfacemembrane,cytoplasm,organelles(fordetailsseeourvideosatPracticalSessionsalsolook a bookofBiology)

  8. SURFACE MEMBRANE

  9. Surface Membrane of RBC

  10. Surface Membrane (SM) Intracellular SM-coverssubcellularstructures(e.g.Nucleus, Golgicomplex, Mitochondria) Plasmatic SM - coversthesurfaceofeachcell Functions:semipermeability,division, protec-tion, integrativeroles, transport ofions, sourceofenzymes, storageofelectriccharges, etc. Composition: SM isPhospholipidbilayer- 45% Hydrophilicheads(consistingofphosphates-soluble in water) Hydrophobictails (consisitingofhydrocarbonfattyacids-insoluble in water- 45%) . Proteinsbilayer (peripheral, integral) - 50% , +Sugar + Cholesterol (5%) Headsare (+) electricallycharged and directedtowardsthemembraneexterior, tailsare chargednegatively (–), beingoriented to membraneinterior

  11. Transport Membrane Mechanisms areresponsibleformovementofwater and solutesacrossthecellmembrane areofvitalimportanceforcellmetabo-lism, forproductionofcellelectricityi.e. (resting and actionmembranepotentials) Types: PASSIVE - itdoesnotneeddeli-veryof a freeenergy. (Simple and Facilita-tedDiffusion, Osmosis, Filtration). ACTIVE - freeenergyfrom ATP isneeded and mustbedelivered(Na-Kpump, Ca-pump, H-pump, exo/ endo-cytosis, and phagocytosis)

  12. Simple Diffusion through cell membrane

  13. Simple Diffusion is a kind of passive membrane transport of H20, solutes, or gases (O2, CO2) from the space with a higher concentration towards the space with lower one (along the concentration gra-dient), untill the equilibrium is established. Total volume of solution does not change in both of spaces. Rate of diffusion:Fick Law: J = - d . conc.grad.[d- koeficient of diffusion] Generally: diffusion depends - linearlyon a conc. gradient, solubility of a matter, and on ambient temperatureNonlinearlydependson a size of particles Types of diffusion: Simple, Facilitated, Throu-gh the protein channels

  14. Scheme of Facilitated Diffusion

  15. Facilitated Diffusion is a passive transport mechanism of bigger molecules (e.g.aminoacids),along a concentration gradient, when substance binds to a protein carrier thecarrier is protein placed within the membrane and undergoes a process of conformation (is a change of its chemistry) afterbinding of moleculeand conformation, the carrier shifts (turns around ) and finally releases substance on an opposite site of a cell membrane

  16. Diffusion through the protein (ion selective) channels is a passive transport of ions Na+, K+, Ca2+, Cl- ,or low molecular soluble sub-stances through the protein channels within the membrane, along the concen-tration gradient Protein channels are :1.“voltage“gated - they are open or closed (gating) due to a membrane electricity,or 2.„ligand“gated-when e.g. a hormone binds to a channel, thus opening it.

  17. „Voltage“ and „ligand“ gated protein (ion selective) channels

  18. Filtration is a passive transport of water and small particles from a space with higher hyd-rostatic pressure to a space with lower one the power that drives Filtration is Pressure gradient of a hydrostatic pressure(not a concentration gradient ! ) examples: filtration and resorption in capillary loop or in kidneys

  19. Osmosis iskindofpassive transport throughthesemipermeablecellmembrane, whenonlywatermovesfrom a spacewithlowerconcentration (lowerosmoticpressure) to a spacewithhigherconcentration (higherosmoticpressure), till to equilibrium.Totalvolumeofsolution in bothcompartmentswillchange. Simply –waterwants to dilute more concentratedsolution(VanHoff´sLaw) normalosmolarity300 mOsm/l- isotonicsolutionwithbloodplasma (e.g. 0.9 % NaCl, or 5% ofglucose)Below 0.9%- hypotonicsolution Above 0.9% - hypertonicsolution example: Osmoticfragilityof RBC ( see practicals)

  20. OSMOSIS – scheme

  21. Changes in sizeof RBC due to osmosis(HAEMOLYSIS)

  22. ACTIVE MEMBRANE TRANSPORTS transport ofmoleculesamongcellsagainsttheconcentration, or electricgradients, a deliveryoffreeenergyfrom ATP iscrucial. Classification:Primaryactive transportthroughtheselectíveionschannels. Pumps : Na +- K+ pump (in allcells),Ca2+- pump (in musclecells), H+- protonpump (in cellsofstomachproducingHCl) Secondaryactive transport when a substance (e.g. glucose)binds on ion (Na+), thenthiscomplex (Na+glucose) iscarriedthroughthemembraneactively (theglucose-Na+contransport), exo-/endo, phagocytosis

  23. Na+-K+ pump (Na+- K+ ATPase)

  24. Na+- K+ pump – scheme

  25. Na+-K+ pump (Na+- K+- ATP-ase) - Itisanenzyme,placedwithinthecellmembrane (number =106 moleculeswithin a membraneofoneneuron) - itcarries3 ionsof Na+frominside to outside, and atthesametime, 2 K+fromoutside to insideofthecell • Itcanexchange max. 200 Na+ and 133 K+ / sec. (maximalcapacityofpump) - Itrequiresdeliveryoffreeenergy (from ATP) • Itisimportantforrenewalofelectriccharges on body cells

  26. Exocytosis, Endocytosis (Phagocytosis)

  27. ACTIVE membrane transports.: Exocytosis and Endocytosis.  Exocytosis - “cell vomiting“ is a release of larger molecules by the protrusion of a cellular membrane, under delivery of energy and Ca2+ ions Endocytosis –“cell eating“ is an uptake of molecules by a cellular membrane, e.g. ingestion of bacteria by leukocytes (phagocytosis). It needs a delivery of energy, too.

  28. Resting membrane potential (RMP) Itisanelectricpotentialdifferencemeasuredbetween (+) chargedcellexterior and (–) chargedcellinterior. Itsvalueisnegative and equals to a SumofEquilibriumPotentialsofall 3 ions (K+, Na+, Cl-). is a resultofmembranesemipermeabilityi.e. differentleakageofcellmembranefor 3 mainions (K+, Na+, Cl-). permeabilityofcellmembraneforionsatrestis: K+ : Na+ : Cl- = 1 : 0.04 : 0.45 K+ : Na+ : Cl- = 100 : 4 : 45 (%) Valueof RMP for nerve cellsis: -70 mV, sceletalmuscle:– 90 mV, heartmuscle:- 80mV, smoothmuscle: -50 mV (non-stabile)

  29. EquilibriumPotential(EP)is a valueofelectricalvoltagethat just stopsthepassivediffusionofions (K+ ,Na+ ,Cl-)alongtheirconcentrationgradientsCellInside (-) chargedCellOutside(+) cha.(because PROTEINS inside) (because Na +outside)

  30. Concentration and electrical gradients of K+, Na+, Cl- ionsOUTSIDE INSIDE

  31. Nernst formulaEach ion has its own Equilibrium Potential (mV) which can be counted: (Nernst counted it only for K+ )

  32. Goldman´sEquationSumationofallEquilibriumpotentials (for K, Na, Cl ) results in a realvalueofRestingMembranePotential ( e.g. V m= -70 mVforneuronalcells)Goldmanncounteditforall 3 ions (theirconcentrationsoutside and inside) +thepermeabilitiesofmembranefor 3 ions

  33. . for comming and attention

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