Biology IGCSE - Circulation Summary Notes

Transport in humans Circulation
Acirculatory systemconsistsofbloodapumpandbloodvessels
wastes
Circulatory systemstransportoxygen andNutrients
God heartwithadoublecirculation
ArteriesAway
fromthe
heart toforeveryonecircuittheblood
theheart
Veinstowards thehearttwice
through
passes
Capillariessmallest
bloodvessels toveins
connectarteries



Thisisgoodforgettingbloodtocapillariesbutthepressurewould
damage itpumpstothelungs pulmonarycirculation
thecapillariessosmallmuscularbloodvesselsArteriolesreducethepressure
whenbloodleavesthecapillariesit isevenlower Theleftsidereceivesoxygenatedblood
Therearesemilunar
valuesinreinstopreventbackflow itpumpsbloodtothebody systemiccirculation
Eachvalvehas3pockets



4
p g theyclosewhenthereisbackflowtofilltheirpockets


heartwherebloodleavestheheartchamberstoenter
Therearevalvesinthe

thechambersoftheheart
arteriesandbetween
fishhaveatwochambered
heartwitha singlecirculation
Loforeveryonecircuittheblood
theheartonce
passesthrough

throughthevena
cava newoxygenated
bloodisreturnedtoheart Pulmonary
by Theheart
veinsintoleftAtrium
beats so
timesper
minuteaverage
Atriacontractforcingbloodintoventricles
throughatrioventricularvalues
Hasitsownblood
supplyoxygencoronary
artery
Deoxygenatedbloodisforcedinto
thepulmonary
therightventricle
arteryfrom
Consists
of uchambersurblood
vessels2pairs valves
into
of
bloodisforced
oxygenated theaortafrom
leftventricle
Bloodfromtheaorta
goestothe
body
Bloodfrompulmonaryarterygoestolungs
Theseptumpreventsoxygenatedanddeoxygenated
bloodfrommixing


Thewalloftheleftventricleisthickertoallowastrongercontractionformorepressurethisallowbloodtobedeliveredtothebodyfasteras itrequiresGlucoseandoxygenforrespirat
therightventricleisthinnerforpressuretobelowerasthelungsarecloserandnottodamagethepulmonarycapillaries
Theheartpumpswhenthemusclescontracttheatriasqueezebloodintotheventriclestheventriclessqueezethebloodintothearteries

Theelectrocardiogram ECG
usedtomonitorheartactivity
bymeasuringpulserateorlistening
tothe ofvalvesclosingusing a stethoscope
sounds

go Thecontroloftheheartdependsuponelectricalactivity
TheEcacandetectdefectsanddisorders
increaseof co removal
Pwaveshowsatriacontracting

ifÉi QRSspikeshowsventriclesrelaxing musclescould'vebeenrespiring
Twaveshowsventriclesrelaxing anaerobicallyduringexercisecreatingan

Heart
rate pulseratearemeasuredinbpm oxygendept

of Duringexercisemuscles
needmore from
energy
Extraoxygen is usedtobreakdownbu
min up lacticacidfromanaerobicrespiration
me

, Hepaticarterysuppliesoxygenatedbloodtoliver
Hepaticportalveinfromgastrointestinaltractspleen
Renalarterysupplieskidneywithoxygenatedblood
Renalveinfromkidneystovena
cava
hardHeartDisease
Asarteriesandveins dividemoretheygetnarrower coronaryarteries
canbecomepartiallyorfullyblocked Poor
diet
Arterioles thenarrowvesselsconnectingarteriestocapillaries peg get
andcap
w esse'sconnectingveins w
Exerciseregularly
LoleadstoCHD Genetics
Shuntvesselsredistribute
bloodtospecific
bodyareas Partial
blockagecausesseverechest
painsangina Age
ExDuringexercisemorebloodtomusclesthandigestivesystem Fullblockagemeanstheheartcan'trespireor go
thelungstoformoxy
haemoglobin




g Aspirintakendailytoreducebloodclotsforminginarteries Itformsasbloodthroughthecapillariesinthe
Pieceofblood takenfrom
vessel alveoli
armorleg
patient's
usedtocreateanewpassagefor
blood
flow Oxy outoxygenasbloodflow
haemoglobingives

throughcapillariesinbody
tissues
Blood


waterhormonesprotein Narrowcathetertubeplaced
Redbloodcellsbio diskspackedwithhaemoglobin
concave inartery o aballooninflates
White
bloodcells ittopress
theplaquetothe
Plateletsinvolvedin theclottingofbloodprotectnewskinasitgrows walls
artery ostentsare
bloodclottingisaseriesofenzymecontrolled thatresultin
reactions placedtokeep
theminplace
theconversionof fibrinogenintofibrin canbecoatedwithdrugs

BloodinDefenseActionofwhitebloodcells
Platelets

Whitebloodcellsdestroypathogens intwoways madeinthe
bone
marrow
Preventcontinuedsignificant
1Phagocytosisphagocytesengulfpathogensanddigestthem loss
blood

usingdigestiveenzymesFragmentofthedigested
pathogen




iii
couldcauseinfection




mi
arereleasedfrom thewhite bloodcell bloodcannotpass
througha capillarybut
other
liquids
can
when
thereis awoundplateletsreleasechemicals
capillarywallsarepermeable
whichhave acomplementaryshapetothepathogenAntibodies thatcausesolublefibrinogentoconverttoinsoluble bloodpressureforcespartoftheplasmathrough
thewalls
bindtothepathogenrenderingitharmless fibrinandformaninsolublemeshtrappingred notalltissuefluidreturnstocapillariessomeentersblindended
Antibodiesattackpathogensinseveral
ways
lactealsfromthevilli inthesmallintestine
makingthemstick
together Agglutinate joinupwiththelymphaticsystem
theircellmembranes
dissolving LymphThefluidinthelymphaticvesselssimilarincompositiontotissuefluid
Neutralising thetoxinssomeofthemexbacteria Mostlymphflowsfrom
thevesselsbeingcompressedwhenmusclescontractinmovementexbreathingwalking
produce Therearevalvesin lymphaticstokeepaoneway flowtowardstheheart
Thereis adifferenttypeofantibodyforeachpathogen lymphnodesswellingsinlymphaticvesselswherelymphocytes pagocytesarestoredrealsedintolymph obloodsystem
lymphocytes
toproducethecorrectantibodiesif
areready Ifbacteriacannotbeingestedbythebloodorlymphitwillbecarriedtolymphnodes
the entersagainmaking
pathogen
you immune Thelymphnodesareapartofthebody'sdefencesystemagainstinfection