Physiology 3 MCQ Questions for Final - PDF

PHYSIOLOGY QUESTIONS: 1) Which of the following ions is responsible for phase 1 of the action potential of working ventricular cardiomyocytes? 1) Increased sodium conductance (gNA). 2) Increased potassium conductance (gK). 3) Increased chloride conductance (gCl). 4) Increased c...

PHYSIOLOGY QUESTIONS: 1) Which of the following ions is responsible for phase 1 of the action potential of working ventricular cardiomyocytes? 1) Increased sodium conductance (gNA). 2) Increased potassium conductance (gK). 3) Increased chloride conductance (gCl). 4) Increased calcium conductance (gCa). RC: 1 2) Which of the following ions is responsible for phase 1 of the action potential of conduction ventricular cardiomyocytes? 1) Increased sodium conductance (gNA). 2) Increased potassium conductance (gK). 3) Increased chloride conductance (gCl). 4) Increased calcium conductance (gCa). RC: 4 3) Which of the following ions is responsible for phase 2 of the action potential of working ventricular cardiomyocytes? 1) Increased sodium conductance (gNA). 2) Increased potassium conductance (gK). 3) Increased chloride conductance (gCl). 4) Increased calcium conductance (gCa). RC: 4 4) Which of the following ions is responsible for phase 3 of the action potential of working ventricular cardiomyocytes? 1) Increased sodium conductance (gNA). 2) Increased potassium conductance (gK). 3) Increased chloride conductance (gCl). 4) Increased calcium conductance (gCa). RC: 2 5 ) In relation t muscle contraction, which of the following statements is FALSE?  1) The sarcomere consists of thin filaments of actin and thick filaments of myosin. 2) The energy is used for the "rowing stroke" of the contraction. 3) At rest, tropomyosin prevents actin-myosin binding. 4) The actual length of actin and myosin filaments does not vary during contraction. RC: 2 6) Which is the primary function of tropomyosin? 1) ATP hydrolysis to produce the rowing stroke 2) To prevent the actin-myosin binding. 3) To fix the cytosolic free calcium 4) To create strong anchors during muscle contraction (latch mechanism) RC: 2 7) During muscle contraction, the energy obtained from the ATP hydrolysis is used to 1) Achieve a strong binding between actin and myosin filaments. 2) Pump calcium into cytosol. 3) Produce the "rowing stroke" of the myosin. 4) Allow detachment of actin and myosin filaments. RC: 4 8) Which of the following circumstances leads to an INCREASE in cardiac output? 1) Decreased afterload. 2) Decrease in heart rate 3) Decrease of the inotropic state. 4) Decreased preload. RC: 1 9) Which of the following circumstances leads to a DECREASE in cardiac output? 1) Increased afterload. 2) Increase in heart rate 3) Increase of the inotropic state. 4) Increased preload RC: 1 10) You receive a 5-year-old patient with bacterial meningitis in the Pediatric ICU. The patient suffers from septic shock, with a tendency to hypotension and tissue hypoperfusion. Which of the following measures seems LESS appropriate in this patient? 1) To try to increase blood pressure by increasing blood volume with a saline bolus. 2) To increase cardiac inotropy by administration of sympathomimetic drugs 3) To increase peripheral vascular resistance by administration of vasoactive drugs 4) To increase positive expiratory pressure on the ventilator to increase cardiac afterload. 11 ) All of the following lead to a preload increase, EXCEPT for: 1) Atrial contraction 2) Expansion of circulating volume by administration of blood products. 3) Increased venous tone. 4) Valsalva maneuver. RC: 4 12) In relation to the cardiac cycle, which of the following statements is TRUE? 1) Atrial systole contributes in normal conditions to 50% of the ventricular end- diastolic volume. 2) During systole, the opening of the aortic valve precedes the closure of the mitral valve. 3) The maximum ventricular pressure is reached during isovolumetric contraction. 4) The closure of the aortic valve precedes the closure of the pulmonary valve. RC: 4 13) Question related to image. The phase of the cardiac cycle indicated by number 1 represents 1) Isovolumetric contraction  2) Cardiac ejection 3) Diastasis 4) Isovolumetric relaxation RC: 1 14) Question related to image. The phase of the cardiac cycle indicated by number 3 represents 1. Isovolumetric contraction 2. Cardiac ejection 3. Diastasis 4. Isovolumetric relaxation RC: 4 15) Question related to image. The "auricular systole" is represented by number: 1. 1 2. 3 3. 5 4. 6  RC: 4 16) Which of the following statements about the cardiac cycle is FALSE? 1) The closure of the mitral valve takes place before the closure of the tricuspid valve. 2) The closure of the pulmonary valve is delayed during inspiration. 3) The closure of the aortic valve is delayed during inspiration. 4) Branch blocks can lead to a reverse splitting of heart sounds. RC: 3 17) Which is the FALSE statement about the renin-angiotensin-aldosterone system (RAAS)? 1) Angiotensin I is converted to angiotensin II by renin. 2) Angiotensin II induces aldosterone release. 3) PAN inhibits the release of renin. 4) Juxtaglomerular cells can detect a decrease in circulating volume, activating renin release. RC: 1 18) The increase in discharge rate of aortic and carotid baroreceptors leads to: 1) Increased peripheral vascular resistance 2) Increased heart rate 3) Increased cardiac output 4) Decreased blood pressure. 19) In conduction cardiocmyocytes, unlike working cardiomyocytes, phase 0 of the action potential depends mostly on: 1) Increased sodium conductance through rapid channels. 2) Increased calcium conductance. 3) Increased potassium conductance. 4) Increased chloride conductance. RC: 2 20) All of the following situations ones can lead to a DECREASE in blood pressure, EXCEPT for 1) Hemorrhage with significant blood loss. 2) Use of negative inotropic drugs (eg, beta-blockers). 3) Sinus node destruction. 4) Increased venous return to the left heart. RC: 4 21) During a normal cardiac cycle, it is FALSE that: 1) The ventricular pressure is maximal during the ventricular ejection phase. 2) The first cardiac sound corresponds to the closure of the atrioventricular valves. 3) The rapid ventricular filling phase occurs at the beginning of diastole. 4) During isovolumetric relaxation, the atrial pressure is greater than the ventricular pressure. RC: 4 22) Which is the main responsible for airway resistance (or non - elastic resistance) during breathing? 1) The upper airway. 2) The trachea and the first eight bronchial tree divisions. 3) Medium caliber airway. 4) Small caliber airway (