Tissues- Biology Past Paper PDF

Tissues Slide13 EpithelialTissues Layers of cells that cover body surfaces Epithelial Cells coverouterskinsurface skinairways EndothelialCells coverinnersurface bloodvessels Cells form sheets for protection or absorption or formglands forsecretion Functions ofepithelial 1...

Tissues Slide13 EpithelialTissues Layers of cells that cover body surfaces Epithelial Cells coverouterskinsurface skinairways EndothelialCells coverinnersurface bloodvessels Cells form sheets for protection or absorption or formglands forsecretion Functions ofepithelial 1 Absorption ofsmallintestine lining 2 Secretion glands 3 Transport kidneytubules STAPS 4 Protection skin 5 Sensory receptors tastebuds Structure 1 Layer arrangement a Simple Singlelayerof cells used for absorption filtration b Pseudostratified Singlelayerwith varyingcell heights c Stratified Multiplelayers of cells Provides protection 2 CellShape a Squamous FlatcellsAllowfor diffusion filtration lungs bloodvesse b Cuboidal Cubeshapedcells Forsecretion corontkidneytubules c Columnar Tall rectangularcells Forsecretion absorption intestines stratified Pseudo Singlelayerof cells Nuclei at basalend of cells Nuclei atdifferent levels Happens becells are so tightly packed it displacesthenuclei  Cillia on surfacehelpsmovemucusandtrapped particles in respiratory tract Foundin airwaysto cleardebris layer multilayer Single flat Cube astratigtielayer appears tall ConnectiveTissue Mostabundant and widely distributed tissue in thebody Characterized bylowcelldensity andlargeextracellularmatrix 1 Loose connectivetissue Ex Adiposetissue fatstorage Loosely wovenfibresthatsurround andcushionorgans 2 Dense Regular Found in ligamentsandtendonsfibres arranged in parallel forstrength 3 Dense Irregular Found in dermisandprotective capsules around organs Fibres randomlyarranged forstressresistancein multipledirections 4 SupportiveConnective Tissues A Cartilage Hyalinecartilage providessupport w flexibility b Bone Compactbonefor structuralsupport mineral storage  5 Fluid ConnectiveTissue Blood Lymph involved in transporting nutrientsoxygen immunecells Connective Tissues Blood 1 Red blood cells Erythrocytes Transport oxygen using hemoglobin Disc shaped no nucleus 2 Platelets Thrombocytes Blood clotting Small irregularlyshaped 3 White blood cells Leukocytes Forimmune defence Agranulocyte a Monocyte Engulfpathogens bLymphocytes Produceantibodies destroyinfectedcells C Eosinophil Defendagainst parasites allergic rxn mutates d Basophil Releasehistamines during allergic in e Neutrophil Firstresponders to infections engulf bacteria Havegranulesin cytoplasm Lackgranulesin cytoplasm MuscleTissues 1 Skeletal Voluntary Attached to bones provides motion heat protection Long cylindrical fibres 2 Smooth involuntary In walls of holloworgans and bloodvessels Slow rhythmical contraction Spindleshaped non striated fibres 3 Cardiacinvoluntary Only found in heart largenumbers ofmitoch so resistant tofatigue Branched striated fibres NervousTissue Responsible for sensing stimuli and transmitting signals throughout body 1 Neurons a Dendrites Receivesignalsfromotherneurons b CellBody Containsnucleus processesinfo C Axon Transmits signals to other neurons muscles or glands 2 Neuroglia CNS and SchwannCells PNS surround Ogliodendrocytes axons and secrete myelin Myelinis a fattyinsulatingsheaththatwrapsaround axonsincreasingthe speeds of electricalimpulses Neurons 1 Sensory afferentneurons Sendssensoryinfofromreceptors to CNS brainspinalchord Ex touch 2 Motor efferentneurons Send infofrom CNS tomuscles 3 Interneurons Relaysignals between sensory motor neurons In CNS Brain Spinal chords Cranial SpinalNerves Cranial Nerves Connectbrain to periphery Spinal Nerves Connect spinal chord toperiphery Tracts Connect neurons in spinal chord brain Organs and Organ System Combinations of tissues thatperform coordinated complextasks areorgans Organs thatfunction together are called organ systems 11 MajorOrgansystems 1 Cardiovascular 7 Endocrine 2 Respiratory 8 Lymphatic 3 Nervous 9 Digestive 4 Skeletal 10 Urinary 5 Muscular 11 Reproductive 6 Integumentary 1 Cardiovascular Blood heart and blood vessels Components Functions Heart pumps blood through blood vessels Blood transports 02 nutrients to cells while removing CO2 and waste Blood defends against diseaseandrepair damaged blood vessels 2 Urinary System Components Kidneys ureters urinary bladder urethra Functions Produces stores eliminates urine eliminates waste and regulates volume chemical compositionof blood Helpsmaintain theacidbase balance of body fluids Maintains body's mineral balance Regulates production of red blood cells 3 Lymphatic System Components Lymphatic fluid lymph andvessels Spleen thymus lymph nodes and tonsils Functions Returns proteins and fluid toblood tract to blood Carries lipidsfrom gastrointestinal Includes structures wherelymphocytes thatprotect against disease causing microbes mature proliferate 4 Skeletal System Components Bones andjoints of body andtheir associated Cartilages Functions Supportsandprotects the body surface area for muscle attachments Provides a Aids body movement Stores minerals and lipids 5 Integumentary System Components Skin and structuresassociated w it Hair nails sweatglands oilglands Functions Protectbody Helpregulate bodytemp Eliminates some wastes Helps make vitamin D Detects sensations suchas touch painwarmth colo Planes Frontal front and back MidSagital left and right Transverse top and bottom Dirqff.fr osieio front vs back Superior Inferior toward head us toward fee Medial Lateral towardmidlineus awaymidline Directions Relative Proximal Distal Closerus Fartherfromattachment point Adduction Abduction Movement to odd orawayabd midline Flexion Extension Decreasing us increasing angle ofjoint Cardiovascular CoronaryArteryDisease Narrowing or blockage ofcoronaryarteries Arrythmias Heartrhythmproblems Functionsof cardiovascularsystem 1 Delivers nutrients hormones signalling molecules 2 Removes metabolic wasteproducts fromtissues 3 Regulatesbody temp Blood circulation Humanbody contains 5L of blood Everycellwithin 100mm of a blood vessel Thisproximity allowsfor diffusion of CO2O2 smallsolutes Pulmonary and Systemic Circulation RightSide movesdeoxygenated blood to lungs Left Side moves oxygenated blood to body Circulatory Systems Pulmonary Vessels Transportblood to andfrom lungs Systemic Vessels Transportbloodto and frombody Arteries Carry blood awayfrom heart Veins Carry blood back to heart 2 Atria Leftand Right receive blood 2 Ventricles LeftandRight pumpblood 4 One way flowvalves tricuspid pulmonary mitral aortic SystemicCirculation Arterial Leftventricle ejects 80mL of blood intoaorta largestartery bolus Bloodflows intomedium sizedarteries and aerioleswhichbranchoff aorta Vessels furtherdivideinto capillaries 1 Aorta 5 Venules 2 Arteries 6 Veins 3 Arterioles 7 VenaCava Capillaries Slowblood flow allowsforexchange ofnutrients metabolicwaste products gases hormones etc btw tissue blood Systemic Circulation Venous return Deoxygenated blood collects in venue Venules lead to medium sized then large veins then finally the Lacava largestvein VenaCava delivers deoxygenatedblood toheart via right trium Blood is pushed back to heart bymuscleaction on veins One values in veins prevent backflow dueto gravity way Systemic Circulation In going tosmallerarteries diameters velocity decrease but the overall area of vascularbed increases Cardiac Cycle 1 Bloodreturns to heartfrom circulation collects in the atrium 2 Atrium contracts pushes blood into ventricle 3 Ventricle contracts ejecting bloodinto circulation Cardiovascular system Electrical Autorhythmic Cells Heart tissuemade of twotypes of heartmuscles 1 Myocardial contractile cells heart contractions 2 Myocardial conductile cells 11 butgenerate spread elecsignals tocontro Characteristics heartbeats Selfexcitable don'trequireexternal signal to fireactionpotential Unstablerestingmembranepotential Spontaneously depolarizeat a set rate Function Pacemaker setrightmicelectrical excitation thatstimulatesheartbeat Conduction System Ensures coordinated contraction of atrial ventricles 1 Sinoatrial SA Node Function Natural pacemaker rhythmiccellsthatgenerateelectrical impulse action potentia Contains auto Ensurescoordinatedcontraction Signalstravel 1mis throughmusclefibres Actionpotential Rise fallofelecpotential across cellularmembrane 2 Atrioventricular AV Node Yo of a secondafter SAnodegenerates an impulsesignalreaches AVnode Function AV regulatesventricularcontractionby delayingimpulse AV is theonly electricallinkbtwatria ventricles AVslowsdownimpulse preventingventriclesfromcontractingtooquickly 3 Bundleof His Afterpassingthrough AVnode signal reaches Bundle ofHis Bundle transmits signal through thecardiacmuscles ofbothventricles Splitsintoleft rightbundlebranches  5 PurkinjeFibres Specialized musclecells w very fast conductionspeeds Theyrelaysignal tothe ventricular walls ensuringventriclescontract Actionpotential in Contractile Cardiaccells Nat ktpumpstuff Actionpotential inAutorhythmicCardiaccells Electrocardiogram ECG ECGmonitors electricalactivity ofcardiacmusclesusingplacementofelectrodes ventricles fullydepolarize P WaveSAnodeinitiates Atriadepolarizes contracts AVnodedelay ventriclesrepolarizecausing T Ventricles depolarize causing the QRSAtria Heartreturnstoresting cycle repolarizes ECGs can diagnose 1 Arrythmias irregularheartrhythms Tachycardia fast Brachychardia slow Fibrilation rapidirregular 2 HeartBlocks Issuesin electricalconduction 3 Myocardial Infraction Damagedheartmuscleduetolackof 02 Pacemakers ICDs Used totreatbrachycardia ICD for highrisk of ventriculartachycardia or fibrilation Detectsirregularheartcontractions delivers elecimpulsetorestore righthm Cardiovascular System Thermodynamics Cardiac cycle blood pressure Cardiac cycle has 2 phases 1 Diastole Ventricles relax and fill w blood 2 Systole Ventricles contractand pumpbloodout BP BPdropsfurtherfromheart ysff.fi heathy 9818 Inflowphase AB BC Ventricularfilling Phase1 Phase2 IsovolumetriccontractionCD Pressure volumestays Phase3 OutflowphaseDE EF Aorticvalveopens blood eject Phase4 Isovolumetric relaxation FA Presure volumestays Systole CDEF Diastole FABC CardiacCycle OpenAV Fillventricle closeAV Emptyventricle relax 1 VentricularFilling Ventriclerelaxed w lowpressure Bloodgoes Atria Ventricle dueto higheratrial pressure AV valvesopen toallow flow 2 Atrial Contraction Final pushofbloodintoventridebefore contraction End of diastole 3 Ventricular Contraction Start of systole Ventricular pressure rises to begreaterthanatrial AVvalves close topreventbackflow Semilunarvalues aortic pulmonary remainclosed Isovolumetric contraction 4 Ventricular Ejection Ventricularpressure exceeds thepressure in aorta pulmonaryarteries forcing semilunarvalues to open Blood ejectedintocirculation End ofsystole 5 Ventricular Relaxation Beginning of diastole Ventricular pressuredrops semilunarvalves close i When t.sicise tiE.Y valvesopen and ventricles start filling again Cardiac cycle Thermodynamics Thermodynamic assumptions neglect changesin kinetic potentialenergy flow steadystate adiabatic isentropic steady Modelling Cardiac Cycle Wi L P P I it in P2 Systolic Pressure Pi Atrialfilling pressure ustg.im PumpingPower Pw V2 End diastolicvolume Pw Wnet h h heartrate V End systolicvolume Cardiac Output CO Volumetricoutputfrom leftventricle co h su h V2 v Ejection Fraction Fraction ofventricularvolumeejected EF 100 EDUEnd DiastolicVolume Eg ExEstimate cardiacoutput co work LV and powerformale P2 112.5 125100 2 112.5 Pa P us Is 4 45 P assume 4 70 V V2 CO Work 0 70 145 45 Wnet 7000 o iY 45 10250mmHgmL 13310 6 1.36J  Bterwnet EF h EF 100 1.36 70 Ef 95.45min 69 10 LeftVentricle Heart Failure Systolic Dysfunction Reducedejectionfraction and enlarged ventriclechamber strokevolume ventricle contractility tvÉniiÉiafÉ diastolic pressure DiastolicDysfunction Increasedresistance to fillin w increasedfilling pressures ventricularcompliance fillingandstrokevolumestrokew enddiastolic pressure LeftVentricular AssistDevice LVADs Mechanical circulatory support for heart failure Bridge to transplant Supportcardiacfn health Destination therapy Longtermtreatment Bridge to recovery Prolonged LUAD can lead to recovery Pumps fraction of blood from leftventricle to aort Axial or centrifugal  Blood Rheology Study ofmaterials w solid fluid characteristics Fluid Rheology Comparesfluids based on shearstress E us shear rate duldy behaviour Newtonian Fluid 2 M qty MJ eg water airmostsimple M fluid viscosity liquids u velocity Binghan Fluid kg eg toothpaste behaves likesolidbelowto but flows like Newtonian above it Casson Ely 2 a key a non newtonian yieldstress pseudoplasticlike behaviour Blood Blood Erythrocytes RedBloodcells make up 95 cellularcontent WhiteBloodCells 0.1 Platelets 4.9 Plasma Liquidcomponent ofblood Contains salt sugars proteins aminoacids fats Main plasmaprotein is Albumin then fibrinogen Newtonian fluid viscosity 1.16 1.35MPa's CP 37 Increase in plasmaviscosity over waterdueto globularproteins Water is 0.69CP at 37C  YieldStressarises duetopresenceof RBCand Fibrinogen H O1 H Hematocrit Ceto5 11jan 8 CF Fibrinogen conc Mp Plasmavelocity ax proteindependentparam E To Sheerstress yieldstress Fibrinogen Protein thatinteracts w RBC In saline RBCs act as newtonian fluid butfibrinogen binds RBCstogether Hematocrit Proportion of blood volume occupied byRBCs RBCstend to sticktogetherwhenclose Normal hematocrit levels 0.35 0.50 Fibrinogen Hematocritcontributeto bloodsnon Newtonian behaviour by yield stress Bloodviscosity 2blood increases w hematocrit Tricky Telformation Nblood decreases with increasing shear rate  some othergraphs I don'tthink is important Mblood decreases as radius of conduit it flowsthrough decreases Forlargevessels 2 is independent ofvesseldiameter As diameter 1 decreases to a point Effectof hematocrit and tube diameter on viscosity At givendiameter hematocrit viscosity Forgiven hematocrit tubediameter viscosity until min point is reached mum Below 7mm viscosity rises sharply as RBC deform squeeze through capillaries so Fahreous Lindquist Effect Observationthatblood viscosity steeply at lowerradii is called th Fahreous LindquistEffect 4 factorsinfluencing AxialAccumulation RBCs migrate towardcenter leavingcellfreeplasma near wall Reducesfriction btwwalls RBC lowering viscosity Limited Number of Laminae Insmallvessels number of fluidlayers lower Moreefficientflow Tanktreading of RBC RBCsspin w plasmamoving liketanktreads Minimizesenergy loss Deformation of RBC RBCbecome bulletshaped insmallvessels Reducesviscosity  For Newtonianfluids For Non Newtonian fluids