Part One Physiology Practice MCQ's

Transcription

1 ,, Part One Physilgy Practice MQ's 1. In the GIT: The salivary glands secrete 1500mls f fluid per day The cln resrbs 2500mls per day The ttal fluid input by diet and secretin is 5000mls per day Remval f the ilecaecal valve, in the human, causes a significant reductin in the absrptin in the small intestine runner's glands are stimulated by the hrmne VIP t secrete alkaline mucus 2. With respect t gastrin, which f the fllwing is FLS? It stimulates gastric acid and pepsin secretin It stimulates grwth f the mucsa f the stmach It stimulates insulin secretin after a prtein meal trpine inhibits the gastrin respnse t a test meal It stimulates gastric mtility 3. With regard t the GIT < which f the fllwing statements is TRU? The inic cmpsitin f ductal saliva is istnic cmpared with plasma The inhibitry cntractin f the external anal sphincter is mediated via the parasympathetic nervus system Secretin stimulates secretin f enzyme and bicarbnate rich pancreatic juice Glucse transprt frm entercyte t interstitium is via faciltated diffusin and GLUT 2 ile salts, secretin and K are chlretics 4. With respect t bdy fluid cmpartments: The cncentratin f sdium in intracellular fluid is 152 meq/i xtracellular fluid is divided int tw cmpartments - plasma and SF Ttal bdy water is 40% f bdy weight Ttal bld vlume can be calculated frm plasma vlume and haematcrit uffers maintain intracellular and extracellular ph cnstant at 7.2 +/- 0.05

2 5. In in transfer acrss the cell membrane all f the fllwing are true XPT: The Gldman quatin indicates that the external cncentratin f Na+ is the mst imprtant factr in resting Sdium mves acrss the cell membrane by passive and active transprt Na+K+TPase is an electrgenic pump and acts as an antiprt cmp is a secnd messenger which prduces its effect via prtein kinase cell may secrete messengers that bind t receptrs n its cell surface 6. Regarding circulatin: The brain has the highest 02 cnsumptin (ml/1 Og/min) f all rgans Renal bld flw (ml/min) and 02 cnsumptin (ml/1 Og/min) is greater than hepatic bld flw and 02 cnsumptin The Mnr Kellie ctrine helps explain why a fall in cerebral venus pressure results in an increase in cerebral bld flw The ushing's reflex describes increased systlic bld pressure, bradycardia and tachypnea in respnse t increased intracranial pressure Nradrenaline has a vascnstrictive effect in all tissues except the liver and skeletal muscle 7. Regarding cardivascular regulatin, which f the fllwing statements is FLS? Increased discharge f atrial stretch receptrs results reduced bld pressure, vasdilatin, and bradycardia. Increased discharge frm the buffer nerves results in a reductin f bld pressure ctin ptentials in the cardiac cnducting system are primarily due t a++ channel pening hlinergic stimulatin f the sinatrial nde causes decreased firing due t increased cnductance f ptassium in the ndal tissue The phenmenn f autregulatin is prbably due t metablic and mygenic mechanisms 8. In the cnductive system f the heart: The time taken fr an actin ptential t pass alng the interndal pathways f the atrium is 0.03 secs The atriventricular nde delay f the cardiac impulse is <0.1 Purkinje fibres transmit impulses at 0.3 m/sec Vagal stimulatin causes the resting membrane ptential f the sinatrial nde t drp t -90mV Fast sdium channels are activated in self excitatry actin ptentials

3 9. With respect t bld flw dynamics, all f the fllwing are true XPT: ccrding t Piseuille's Law, the rate f bld flw is prprtinal t the furth pwer f the radius patient with plycythemia exhibits faster bld flw in the capillaries than an anaemic patient Increasing arterial bld pressure between 70 and 175mmHg causes nly a 30% increase in bld flw Reactive hyperaemia can be explained by the vasdilatin effect f adensine Nitric xide has a rle t play in dilatatin f large vessels after release frm endthelial cells 10. With respect t regulatin f bld pressure, which f the fllwing statements is TRU? arreceptrs are active until arterial pressure is belw The cartid and artic bdies are imprtant arterial pressure cntrllers between mmhg The lw pressure receptrs in the atria cause a small rise in pressure in respnse t declining pressure The cartid sinus elicits the ainbridge reflex which causes and increase in heart rate and cardiac cntractility The NS ischaemic respnse is caused by 02 accumulatin in the vasmtr centre 11. ardiac utput can be measured by which f the fllwing methds? linical assessment Via an arterial line Via a central venus catheter Via an esphageal dppler prbe Via a pulse ximeter 12. ncerning bdy fluid cmpartments in an average 60 yr ld man, which f the fllwing statements is TRU? Ttal bdy water is -70% bdy weight The ttal bld vlume is -8% bdy weight part frm water, 15% f bdy weight is prtein, 25% fat and 7% minerals The intracellular cmpnent f bdy water accunts fr 60% f ttal bdy water The extracellular cmpnent f bdy water accunts fr 40% f ttal bdy water

4 13. With regard t bdy slutes, which f the fllwing is FLS? The cncentratin f OH ins in water at ph 7 and 25 degrees elsius is 107 mlll 1 N slutin f saline cntains 58.5 gil The ph f IF is in health Osmlality is nt affected by the temperature f the slute 1 sm slutin f NaI = 58.5g/2 14. Which f the fllwing is TRU f Na/K TPase? It helps t maintain the resting membrane ptential f neurnal cells at -gomv It is imprtant in the maintenance f nrmal cell pressure It is inhibited be digitalis and calcium antagnists It has phsphrylatin sites n the beta-subunit The mvement f Na and K thrugh it's channel is simultaneus (ie. an anti prt 15. Which f the fllwing statements abut thyrid hrmnes is FLS? Thyrid hrmnes increase R 2,3 PG Mypathy can be a feature f thyrid hrmne excess r deficiency Thyrid hrmnes lwer circulating chlesterl levels by increasing the number f hepatic ll receptrs T3 is mre ptent than T 4 erebral 02 and glucse cnsumptin are reduced in hypthyridism 16. Which f the fllwing statements regarding insulin and glucagn is FLS? Stimulatin f beta receptrs stimulates the secretin f insulin and glucagn lanine and serine stimulate glucagn secretin Gluccrticid excess causes increased affinity f insulin receptrs fr insulin bld glucse f mml/l is likely t cause cnvulsins and brain damage Reduced hepatic glucse utput and increased glycgen synthesis are features f insulinma 17. Insulin is released in respnse t decreased intracellular TP cnsists f 63 amin acids reduces circulating free fatty acids reduces muscle glycgen stres is released in respnse t sympathetic stimulatin t the

5 18. [n renal bld flw: Prstaglandins reduce bth crtical and medullary flw Kidneys receive 40% f cardiac utput ngitensin II has a greater cnstrictr effect n efferent than afferent arteriles Sympathetic stimulatin will increase flw via a[pha1 High prtein diets have n effect n renal bld flw 19. Which f the fllwing statements abut pancreatic activity is TRU? xcrine pancreatic secretin is largely under vagal cntrl Lw flw rates are asssciated with a less alka[ine prduct as a result f H03/I exchange in the ducts Pancreatic juice cntains trypsingen, pre[astase, lipase and enterpeptidase K results in the prductin f a watery, enzyme pr, H03 rich prduct Secretin is a prmter f pancreatic secretin that als acts n the stmach t inhibit gastric acid prductin and relax the pylric sph incter 20. Which f the fllwing statements abut plypeptides secreted by neurns in the enteric nervus system is TRU? VIP causes inhibitin f gastric acid secretin Substance P stimulates pepsin secretin GRP causes the release f gastrin Smatstatin stimulates intestinal mtility K prmtes gastric emptying 21. Gastrin is mainly prduced in the: Fundus f the stmach cells f the pancreas G cell in antrum f the stmach G cells f the pancreas dy f the stmach 22. Which f the fllwing statements abut bile and its cmpnents is FLS? i[iary secretin f chlester[ is an imprtant means f regulating chlesterl stnes Lecithin is a cmpnent f bile exych[ic acid is a secndary bile salt hlecystkinin (K) is the majr hrmne regulating bile prductin 90-95% f bile salts in the small intestine are reabsrbed

6 Regarding ttal bdy water, which f the fllwing is FLS? (] TW in males 18-40yrs is 61% TW in males 40-60yrs is 55% TW in females 18-40yrs is 57% TW in females ver 60yrs is 46% TW in males ver 60yrs is 52% 24. Which f the fllwing is TRU f Iyssmes? Frmed by the endplasmic reticulum apable f breaking dwn mst cell cmpnents except N Mre acidic than the rest f the cytplasm Zellweger syndrme is a lyssmal strage disease ntains abut 40 different xidative enzymes 25. Which f the fllwing statements abut synapses is TRU? Spatial summatin f synapses may be present when activity is present in mre than ne synaptic knb at the same time Presynaptic faciliatatin is prduced when a2+ channels are clsed Occlusin is an increase in expected respnse due t presynaptic fibres sharing pstsynaptic neurns Renshaw cells are excitatry interneurns IPSPs (inhibitry pstsynaptic ptentials) are prduced by clsing K+ channels 26. With regard t smth muscle: Z lines are prminent Micrscpically striatins are prminent It has trpnin n increase in tensin varies accrding t the Starling's law Tensin is variable fr any given length 27. With regard t tubulglmerular feedback: GFR increases when the flw thrugh the distal tubule The macula densa n the efferent arterile is the sensr The afferent arterile is cnstricted by thrmbxane 2 It is designed t maintain sdium reabsrptin GFR is influenced by minr changes in bld pressure

7 28. Which f the fllwing statements cncerning neurnal cells is FLS? The number f ins respnsible fr the membrane ptential is a minute fractin f the ttal number present. The cell membrane is mre permeable t Na+ than t K+ ins. The ttal cncentratins f psitive and negative ins are equal everywhere except alng the membrane. The cncentratin gradient fr I- acrss the cell membrane is exactly balanced by the ppsitely directed electrical Na+-K+TPase causes bth an electrical and cncentratin gradient acrss the cell membrane. 29. Select the mst crrect sequence in prtein synthesis. N ->mrn->trn->amin acids->prtein N->pre mrn->mrna->trn->amin acids->prtein N->fRN->mRN->amin acids->prtein pre mrn->n->mrn->trn->amin acids-> prtein mrn->n ->amin acids-> prtein 30. Which f the fllwing statements is FLS? The nrmality f a slutin is the number f gram equivalents in ne litre F in Iitres can be apprximated t 20% f bdy weight The altn is a dimensinless measurement Osmlality is the number f smles per kg f slvent Inulin can be used t measure F vlume 31. Which f the fllwing statements is FLS? The nuclelis is the site f synthesis f ribsmes trn attaches amin acids t mrn c-fs is a result f an immediate early gene Heat shck prteins bind t sterid receptrs llid smtic pressure is abut 15mmHg 32. Which f the fllwing statements is FLS? Methylxanthines inhibit phsphdiesterase and s decrease cmp denylyl cyclase is a transmembrane prtein ndplasmic reticulum is an intracellular stre fr a++ ytplasmic calcium is usually - 1 On mil Small G prteins are invlved in vesicle transprt in cells

8 33. Which f the fllwing factrs is NOT affected by warfarin? IX VII Prtein Prthrmbin Kallikrein 34. Regarding ernulli's Principle: rtery end pressure is higher than the side pressure by the amunt f kinetic energy f flw The greater the velcity f flw in a vessel, the higher the lateral pressure distending its walls The pressure drp in any segment f the arterial system is due principally t cnversin f ptential int kinetic energy The ernulli Principle relates transmural pressure t the tensin in the wall and the radius f the vessel. When a vessel is narrwed by a pathlgic prcess, the lateral pressure at the cnstrictin is increased 35. With regard t chemreceptrs, which f the fllwing statements is FLS? entral chemreceptrs are mst imprtant in altering ventilatin resulting frm changes in bld p02 Hypxaemia stimulates ventilatin mre by peripheral than central chemreceptrs ecreasing bld ph stimulates ventilatin predminantly by its effect n peripheral chemreceptrs entral chemreceptrs respnd mre t changes in F than SF Rutine minute-t-minute adjustments in ventilatin are mediated via peripheral chemreceptrs 36. Lung cmpliance is INRS: at high lung vlumes with increasing pulmnary pressure by diseases causing fibrsis f the lung with increasing age if the lung remains unventilated fr a lng perid 37. hemreceptrs in the brainstem are directly affected by: arbn dixide Hydrgen ins Oxygen Neural input arbnic acid

9 38. Renal bld flw is NOT directly affected by: drenaline Renin Sympathetic nervus system ngitensin II utregulatin 39. Which f the fllwing plasma cnstituents is nrmally cmpletely reabsrbed by the kidney? H03- Na+ I a2+ K+ 40. Regarding typical nephrns: There are apprximately 1.3 millin nephrns in the bdy. The glmerulus is apprximately 100 micrns in diameter Mesangial cells are lcated between the pdcytes and basal lamina The distal cnvluted tubule is apprximately 5mm lng The ttal area f all glmerular capillary endthelium fr filtratin is abut 8 metres square 41. Pressure sensatin is carried n: fibres beta fibres delta fibres fibres gamma fibres 42. Osmtic pressure: depends upn the number rather than the type f particles in slutin. is the pressure necessary t prevent slute migratin. is directly prprtinal t the vlume f the slutin. is nt influenced by the temperature f the slutin. all f the abve

10 43. Which f the fllwing rganelles is NOT surrunded by a membrane? Lyssmes ndsmes Mitchndria entrismes ndplasmic Reticulum 44. Which f the fllwing is NOT a majr cntributr t plasma smlality? I- Urea K+ Glucse Na+

11 ,.. ' Part One Physilgy Practice MQ's NSWRS