MCQs on Cardiovascular System
1. This is the reason why the SA node acts as heart’s pacemaker
(a) because it has a poor cholinergic innervations
(b) because it has a rich sympathetic innervations
(c) because of its capability of generating impulses
(d) because it generates impulses at the highest rate
Answer:: (d)
2. This about second heart sound is incorrect
(a) it is occasionally split
(b) it is due to the closure of semilunar valves
(c) indicates the commencement of diastole
(d) it has a longer duration than the first sound
Answer:: (d)
3. The reason for the dicrotic notch on the aortic pressure curve is
(a) contraction of aorta
(b) closure of the aortic valve
(c) rapid filling of the left ventricle
(d) closure of the pulmonary valve
Answer:: (b)
4. Rise in the carotid sinus pressure leads to
(a) reflex hypercapnia
(b) reflex hyperpnea
(c) reflex bradycardia
(d) reflex tachycardia
Answer:: (c)
5. Peripheral vascular resistance can be best given by
(a) pulse pressure as it corresponds to aortic compliance and stroke volume
(b) mean arterial pressure as it supplies blood to organs
(c) diastolic blood pressure as it leads to the decrease till mid-thoracic aorta
(d) systolic pressure as it causes an increase in the descending aorta
Answer:: (c)
6. Duration of the absolute period, i.e., when the whole of heart is in diastole is
(a) 0.2 seconds
(b) 0.1 seconds
(c) 0.4 seconds
(d) 0.7 seconds
Answer:: (a)
7. This sets glomerular capillary pressure apart from other capillaries found in the body
(a) Lower filtration pressure
(b) Higher filtration pressure
(c) Both (a) and (b)
(d) none of these
Answer:: (b)
8. The ventricular muscles accepts impulses directly from
(a) AV node
(b) Bundle of His
(c) Right and left bundle branches
(d) Purkinje system
Answer:: (d)
9. This is the similarity between pulmonary and systemic circulation
(a) total capacity
(b) pulse pressure
(c) peripheral vascular resistance
(d) volume of the circulation per minute
Answer:: (d)
10. On the heart, the impact of adrenaline is all of these except that
(a) it increases the uptake of oxygen by the heart
(b) it increases the contraction force
(c) it decreases the myocardial irritability
(d) it increases the heart rate
Answer:: (c)
