Previous Year Question Patterns and Exam Strategy

Most tested concept (3+ years): SAN as pacemaker — asked in NEET 2019, 2021, 2023; always choose SAN; never AVN
Most tested exception (3+ years): Pulmonary artery carries deoxygenated blood — tested in NEET 2018, 2020, 2022; pulmonary vessels are the exception to artery/vein conventions
High-yield ECG question (2 recent years): QRS complex = ventricular DEPOLARIZATION not contraction — tested in NEET 2020, 2024; this is the #1 ECG trap
Blood group universality: Universal donor = O-negative; universal recipient = AB-positive; tested directly and in clinical reasoning scenarios
Cardiac cycle timing: Values 0.1 s (atrial systole), 0.3 s (ventricular systole), 0.4 s (joint diastole), 0.8 s (total) are directly asked; joint diastole is the longest
Erythroblastosis fetalis mechanism: Rh-neg mother sensitized at first delivery → antibodies in second pregnancy; prevention = RhoGAM within 72 hours
WBC differential: Know that neutrophils are most abundant (60-65%), basophils are least (0.5-1%), and their specific functions distinguish them in MCQs
Valve names and locations: Tricuspid = right AV; bicuspid/mitral = left AV; semilunar valves at ventricular exits — confusing right vs. left valve is a common source of error
Strategy insight: This chapter has predictable question patterns. Master the 6 "trap" facts (SAN pacemaker, pulmonary artery exception, QRS = depolarization, RBC site of formation vs. destruction, universal donor vs. recipient, erythroblastosis fetalis timing) and you can confidently claim 4-5 NEET marks
Assertion-reason format: Increasingly common in NEET for this chapter; practice distinguishing true/true + correct explanation vs. true/true but incorrect explanation, especially for AVN delay and pulmonary circulation