airns ase Hspital mergency epartment Part 1 FM MQs 1 ncerning the cardiac actin ptential Phase 1 is due t rapid sdium influx Resting membrane ptential is typically -90mV Phase 2 results frm slw prlnged pening f sdium channels The actin ptential lasts 20ms Phase 3 is due t ptassium efflux nly 2 ncerning the cardiac cnductin system The sinatrial nde is the cardiac pacemaker due t its anatmical lcatin The delay at the V nde is O.Sms The bundle f His has the highest cnductin rate The cnductin rate thrugh the S and V ndes is 1m/s The cnductin rate thrugh the Purkinje system is 4m/s 3 Regarding pacemaker ptentials eplarisatin is initiated by pening f calcium channels lng-lasting calcium channels pen t prduce the pre-ptential The resting membrane ptential is -90mV Replarisatin is caused by pening f ptassium channels Sympathetic stimulatin results in hyperplarisatin 4 Ventricular ejectin is phase 2 f the cardiac cycle 8 is f cnstant rate thrughut the phase results in peak left ventricular pressure f 120mmHg ejects 120ml f bld immediately precedes isvlumetric cntractin 5 ncerning the cardiac cycle 70% f ventricular filling ccurs as a result f atrial cntractin 8 Phase 1 crrespnds t isvlumetric cntractin Phase 2 lasts O.OSs Phase 4 is ventricular filling Mst crnary bld flw ccurs in systle Physilgy - heart, circulatin and cardivascular hmestasis
airns ase Hspital mergency epartment Part 1 FM MQs 6 Regarding the jugular venus pulse The a wave is caused by atrial diastle 8 The c wave is due t atrial cntractin The v wave is caused by pening f the V valve annn waves ccur in tricuspid insufficiency cmplete heart blck des nt cause a wave abnrmalities 7 Regarding heart sunds The 3rd sund is always pathlgical 8 The 2n d sund is shrter than the 1st The 4 th sund is due t nrmal rapid ventricular filling Splitting f the 2" sund is pathlgical rtic insufficiency will cause a systlic murmur 8 The fllwing cnditins affect cardiac utput XPT Pregnancy High envirnmental temperature Sitting frm a lying psitin ating Sleep 9 The Frank-Starling curve shifts t the right as a result f irculating catechlamines Sympathetic stimulatin igxin Hypxia lkalsis 10 ncerning the percentage f bld vlume cntained in the cardivascular system, which f the fllwing is crrect? Venus system - 54% rta -12% apillaries - 23% rteriles - 5% Heart - 25% PhYSilgy- heart, circulatin and cardivascular hmestasis
airns ase Hspital mergency epartment Part 1 FM MQs 11 ncerning arterial circulatin rtic flw is 10m/s Negative artic flw may ccur in diastle The windkessel effect describes the effect f gravity n arterial pressure Mst resistance ccurs in the large arteries rterial pressure in the ft during standing exceeds 250mmHg 12 Functins f the lymphatic system include all f the fllwing except transprt f lng chain fatty acids frm the intestine transprt f prtein remval f cltting factrs cntrl f interstitial fluid vlume carriage f bacteria t lymph ndes 13 Substances secreted by the endthelium include all lthe fllwing XPT Prstacyclin Thrmbxane 2 Nitric xide ndthelins ngitensin cnverting enzyme 14 Vaspressin is prduced by the anterir pituitary decreases the permeability f the cllecting ducts t water exerts its antidiuretic effect via Vz receptrs exerts its vascnstrictr effect via Vl receptrs is released in respnse t reduced plasma smtic pressure 15 Which f the fllwing is the mst ptent vascnstrictr radykinin ngitensin II Nradrenaline drenaline Neurpeptide V Physilgy- heart, circulatin and cardivascular hmestasis
airns ase Hspital mergency epartment Part 1 FM MQs 16 The fllwing factrs cause vasdilatin ndthelin-1 Hypkalaemia Hypthermia Neurpeptide Y Substance P 17 The rgan with the greatest bld flw per gram is rain Heart muscle Liver Kidney Skeletal muscle 18 The percentage f cardiac utput received by the brain is 3% 13% 23% 33% 43% 19 ncerning the cerebral circulatin The capillaries cntain n fenestratins, thus maintaining a bld/brain barrier It is nt pssible t measure cerebral bld flw by the Fick methd Hypertensin assciated with the cushing respnse is due t ischaemia The Mnre-Kelly dctrine states that cerebral bld vlume is inversely prprtinal t (SF vlume utregulatin is ineffective abve 120mmHg 20 The fllwing rgans lie utside the XPT nterir pituitary Psterir pituitary rea pstrema OVLT Subfrnical rgan Physilgy - heart, circulatin and cardivascular hmestasis
airns ase Hspital mergency epartment Part 1 FM MQs 21 The fllwing substances passively crss the SS with ease Free hydrgen min acids icarbnate hline arbn dixide 22 ncerning SF 1500ml is prduced per day 70% is frmed by the chrid plexus icarbnate is higher than in plasma ph is usually 7.50 r higher Glucse is higher than in plasma 23 ncerning barreceptrs arreceptrs are spray-type nerve endings in the walls f arteries arreceptrs are nly lcated in the cartid sinus and artic arch Respnse t statinary pressure is greater than t rapidly changing pressure Impulses are transmitted t the vasmtr centre lcated in the midbrain Impulses lead t stimulatin f the tractus slitarius 24 ncerning nervus cntrl f circulatin The ainbridge reflex is peripheral vasdilatin in respnse t atrial stretch The NS ischaemic respnse activates belw loommhg rterial chemreceptrs prvide minute t minute P cntrl in nrmal circumstances trial stretch causes reflex renal vasdilatin fferents frm barreceptrs reach the medulla via the vagus and phrenic nerves 25 ncerning crnary bld flw In keeping with ther rgans, bld flw is greatest in systle Subendcardial flw is greater than epicardial flw at all times f the cardiac cycle rnary artery flw is largely dependent n sympathetic cntrl densine is released in respnse t hypxia utregulatin is less imprtant than nervus cntrl f bld flw Physilgy - heart, circulatin and cardivascular hmestasis
airns ase Hspital mergency epartment Part 1 FM MQs 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Physilgy - heart, circulatin and cardivascular hmestasis