3.3 Cardiac muscle, blood, Flashcards

Question

How measure blood vol how distribu various parts system

Answer 1

Indirect - plasma vol / hct direct radiochromium labelled red cells plsams voul - tracer evans blue binds albumin ``` 65% veins 13% artery 2%arterioles 5% capil 15% central blood vol ``` recumbent - less bood peripheral vein 55% more central blood volume 25%

Answer 2

Blood heart and lungs - thorax 350 heart diastole 450 lungs context discuion vasoactive drugs - intense symp stim - periphral vasocn 0 iv adrean tfer peripheral blood to central 0 increase size central volume

Answer 3

Circ close loop return blood periph to heart High compliance - accom lot blood if increase actuley - bbuffer adverse effect increasevol 25x complaince arterial system veins 4x capcity artery cmpliance 6 times artery artery pressure rise 25mmhg accomad same bloood vol that would cause 1mmhg rise venous ca constrict counteract adverse effect hypovol circ fxn

Answer 4

Conduction - function distribution blood to circulation auxiliary pump during diastole body sv - delivery elastic aorta during systole diastole potential energy stored stretched walls - concerted kinetic energy maintain blood flow pressure drop 120-80 where ventricle 120-0 Flow ventricles intermittent flow from aorta large elastic arteries continuous - pulsatile component but still has pulsatile components

Answer 5

Aorta auxil pump obtai contin pulsatile flow muscular artery - distrbute oxygenated blood tot issue arterioles- restiance vessel - system vascular ressistance determine ditrsib co capilarry exhcange vessel - veins capic return blood heart lungs - cotrain central vol - pump and gas exchange all togerhter closed ciruc pump oxygenator designed dsitrub & exchange

Answer 6

change restriance local control flow Local vary resistance allows local control blood flow - match tissue requirement function - autoregulation sum all local organ tissue flow in body co - tissue via change art resist -control co heart act demand pump supply required flow general control pressure Symp control arteriolar resistance maint art bp - stable bp required assist control tissue flow - autoreg

Answer 7

Ohms law - flow equal change pressure divided resistance Q = Delta P/ R Now if pressure relative constant - flow depend only resistance constancy pressure venefecial tissue control local flow - tissue regulatte own ressitance genereally unable affect systemic pressure much if could adjust flow - affect allother organ other adjust new pressure - adjuct local resistance - change bp - facourable level - need altered flow one organ interefre with flow other organ cosntant bp allows each tissue adjust flow - adjust local resitance allows tissue indep each other control local flow - effect system mainta constant bp - nervous sys - sns import tissue - low level neurgoenic control - flow not particularly adversely affected sympatetitc mediate casocon tissue gain benefeit also tissue control o cosneq autoge own supply heart act as demand pump to delvier co nervous sytesm maintsins constant pressure head - arterial pressure allow tissue adjust indep others some adverse affect bascon - impratnt low level nervous otrnol and autoreg both autoregulation sns - achieve effects change arteriolar resitance

Answer 8

generalyl - whole veonous system some hold signif blood - venocon increase vr increaes bv most improtant lungs liver skin resevor spleen only minor blood resevor human large veins limbs - act reservoir - important response change positive splanchnic vcon increase effective blood vol signif

Answer 9

As hb is Major carrier for oxygen blood - anaemia decrease in oxygen content given volume blood Three major mech tresponse maint tissue oxygen avail Icnrease co - delivery Increase oxy extraction - (grad increasr lower po2, increase 2 3 dpg - odc right sift redist flow - adeq o2 deliver more crtiical

Answer 10

Mainta deliver despite lower conent mech 0 autoreg cuases arteriolar vdil - increase lblood flow required supply increase o2 demand All tissue affect - vasdil all tissue - drop svr increase tendency vr co - heart meet demand - pssible provided pump fuction main and not hypovolaemic oxygen flux eqn oxy delivery = CO x Hb X sat x 1.34 Presence acute anaemi - Co one four terms body increase acutely increase CO - increased myocardial o2 consump - corpmoised if hb too - <5 Drop BP - renal retnetion Na & h20 increase blood vol assist achive Co kidney able tolerate decrease blood flow - allow resit EPO increase increase pro new RCC

Answer 11

Red cell 2 3 dpg rise in ameia incrase p50 hb to 30mmhg Doesnt impair o2 uptake in lunsg - flat upper part odc - right shift improve unloading Improve tisseu ability extract more o2 for each gram hb - some increase extraction in response to lower PO2 - even if not right shift - right shift help mintain gradient for diffusion

Answer 12

Loss hb and decrease circ blood vol hypovol mimit amount CO can increase Singif acute blood loss reulst ``` Decrease CVP= 1 Decrease strethc low pressure baro = increase adh increase symp activity -hr vcon ``` 2 Decrease ABP decrease firing rate high pressure baro rec increase sypmathetic activity - vascon aff art increase renin jg cell - increas ang II aldo Reflex symp stim - compensatory change limit drop in BP - help maint CO health adult - nearly fully compensae Redist blood kidney heart and brain improatn Symp med remal vcon - decrease RBF & GFR Urine flow - decrease markedly help conserve volume increase ADH & ALdo - important renal salt and water retention Body response max effective blood vol main co veoncon - reseover vol tfer ISF it IV - change balance starling decrease urine flow Fluid isf - main blood vol - fall hb oxygen content fall vascon - decrease CO important tend maint art pressure -assist redist flow prefernt -> myocard cerebral metabolic autoreg organs - overrides local smypathtic mediated vasocon If excess loss = shock decompensatory mech logner term -plasma pretin sythn 3-4 days epo rcc 4-8 weeks

Answer 13

Pricnple miantin o2 avail tissue - adeq norml function repvent lactic acidos maximise stissue o2 supply minimise oxygen demand CO - volume artifical hb sat - ensure sao2 iron tablets support marrow production oxygen combing power hb

Answer 14

Sedation minmise act artifical vent - muscle relax external measure body temp 36 min inotrops - main co with vol if possible

Answer 15

Acute sym stim - skin cascon avute hb - pale appear redist isf blood - drop tufsion accel soln - csl - restore volume but drops hb patients signif trauma - clothes removed facil manegment - heat loss

Answer 16

Vis a tergo - push from behind Pressure responsible for vr ohms law flow equal pressure diff divdied resitance VR = MAP -RAP/trp Mean sytem pressure - mean pressure at quil if heart stop beating represent measure degree filling system scirc driving force retunr blood to right side icnrease inbcrase blood vol & venocon Guyton curve - equals RAP @ point venous return is 0 VR = MSP-RAP / VR MSP is about +7 - positive value - over filling

Answer 17

Muscle pump throacic pump intrapericardil pressure venous tone artrail cintrib ventric filling posture blood volume factors affect VR - affect msp rap vr neg intratho pressure decrease RAP - increase pressure grad - favour return in rap 0 thoracic pump not have affect VR veins chest collapse when pressure subatomos increase intraperidcard pressure increase RAP - restrain effect for VR Venous tone - ceno increase return Position - pooling blood posutal hyptension

Answer 18

page 99 hyperbvol shift up and right - msp increase overfilling circ cardic function not affect net result in rap and vr - seen new euilib point hypovol - ooppostie decrease msp rap and vr

Answer 19

ABC Clear airway adeq vent - easy intubated lungs normal main prob resus adeq circ not contracting mech cuase blood flow during CPR 2 theoryies cardiac pump hypothesis external chest compression compress heart between sternum and thoracic vertebral colum - inc intracard pressure pressure grad flow valves ensure unidrection alt idea - thacic pump meach - obeser VF cv lab remain concious by repeat coughing some co - obrain whtiout external cardiac comperssion proposed expalnion increase ithratoacic pressure - d/t tmit heart and thoracic vessels increase pressure promote forward flow mech prevent revs3er flow - valve at thaorcic inlet equal tmision venous net pressure gradient accross circ - cause forward flow

Answer 20

Page 101 Radial pulse - transmission pressure wave to periph clearly disting flow blood Pressure wave travels faster than flow blood inded pressure wave recorded even if total disatl occulsion rad arter - no blood flow Radial pressure wave means heart pumping - mech activity presenve evg - presence eletrical activity if elecrotmech dissoc pressent - ecg recorded radial pressure curve abset

Answer 21

Radial curve- delayed onset - time taken travel distorted shape - various factors reflection resonance daping occuring arterial tre - diff speed tmsiion diff component Radial curve Taller - higher systolic pressure Narrow at peak - higer velocity of higher pressure peak does not have incisura -0 d/t damping of high pressure component diastolic hump - reflection and resonance Radial pressure high - mean pressure not much different than mean pressure centrally

Answer 22

change =- decrease compliance aort decreased myocardial perfomrnaace aortic curve- slower upstroke - decrease contractiliy Higher peak - lower aortic compliance if systolic peak partic elevated - systolic htn Lower aortic compliance - pressure wave travel faster - less distorted from contour aortic curve change elderly different younger - diff aortica radial curve less

Answer 23

Theoretical pressure - sometimes represent force promiting VR whole circ - halt asytole without circ reflex equilb pressure measure is mean systemic pressure normal est +7mmHg Positive - degree overfilling circ system driving force promoting VR MSP - increased w/ increase vol, vencon vascular fuxn curve RAP increase - VR decrease RAP so high VR cease RAP equal msp

Answer 24

page 103 `Vascular fuxn - effect increase CO - independ variable on RAP - depend if CO 0 RAP = MSP 7mmHg Periph resistance not altered Max value CO limited RAP becomes neg veins collapse Cardiac function curve shows effect increase RAP - indep vary on CO - dep vary hetreometic autoreg frank starlin mech Rship mech - coupling heart and periph circ Point 2 curve cross equil point CO - RAP @ cvs operates

Answer 25

equil - point state cvs represented by two curve Venocon increase MSP - moves curve up and right - result increase vr @ given RAP Increase blodo vol same effect vendoiln - opposite effect Vascon not much effect on MSP - 2% vol in arterioles increase bp and vent after- fall VR & CO = net result curve rotate down msp not altered

Answer 26

venous tone or blood volume not affect position cardiac fxn curve curve alter positon vasculr function curve and shift position equil point hypervol shift up equil point up and cardiac function so system working high co and hgiher RAP Change Afterload increase art pressure - change position both curve cardiac function curve - different tradition frank staling curve vent function show frank starling rship not affect change after increase contractility - shift up and left diagr page 104

Answer 27

10VC rapid succession breaths bear hug - unconc loss conc - crit low cbf factor - hypocap & valsalsva Hypcap - dec cvf potent linear over wide range pco2 cbf - decrease 4% per mmhg pco2 if hpyernet actuely reduce then cvf decease byy 60-lighthead not enough cause unconc BP pressure falls phase 2 valsalva - impair vr to left heart - increase intratoacic pressure causes increased venous pressure in jugualr jug CPP Decrease decreaed carotid arterial pressure incrase jug venous pressure CBF - CPP/CVR both affected negatively affect cbf cbf crit reduced - unconc occurs - fall limp hypoaxaemia not factor recovery concious rapid conc lost - glottis opens - expiration restores intrathoracic pressure cbf recovers conscious return