Bulleted High-Yield NEET Facts

Blood = 6-8% body weight; Plasma = 55%; Formed elements = 45%
Plasma proteins: albumin (osmotic pressure), globulins (immunity), fibrinogen (clotting)
Serum = plasma minus fibrinogen (after clot formation)
RBC lifespan = 120 days; formed in red bone marrow; destroyed in spleen (graveyard)
RBC count: male 5-5.5 million/ $mm^{3}$ ; female 4.5-5 million/ $mm^{3}$ ; biconcave and anucleate
WBC order by abundance (Never Let Monkeys Eat Bananas): N(60-65%) > L(20-25%) > M(6-8%) > E(2-3%) > B(0.5-1%)
Neutrophils = phagocytosis (bacteria); Eosinophils = allergy + parasites; Basophils = histamine + heparin
B-lymphocytes = antibody/humoral immunity; T-lymphocytes = cell-mediated immunity (mature in thymus)
Monocytes → macrophages in tissues
Platelets from megakaryocytes; count 1.5-3.5 lakh/ $mm^{3}$ ; lifespan 5-9 days; initiate clotting
ABO: O = universal donor (no antigens); AB = universal recipient (no antibodies); TRUE universal donor = O-negative; TRUE universal recipient = AB-positive
Rh factor = D antigen; erythroblastosis fetalis: Rh-neg mother + Rh-pos foetus (2nd+ pregnancy)
RhoGAM (anti-D IgG) given within 72 hours after first Rh+ delivery prevents sensitization
Heart in mediastinum; tricuspid (right AV); bicuspid/mitral (left AV); pulmonary + aortic semilunar valves
Conducting system: SAN (70-75 bpm) → AVN (0.1 s delay) → Bundle of His → Purkinje fibres
SAN = primary pacemaker; AVN = secondary (40-60 bpm); Purkinje = tertiary (20-40 bpm)
Cardiac cycle = 0.8 s: atrial systole 0.1 s + ventricular systole 0.3 s + joint diastole 0.4 s (longest)
CO = SV × HR ≈ 5 L/min at rest; can reach 20-25 L/min during exercise
ECG: P = atrial depolarization; QRS = ventricular depolarization (NOT contraction!); T = ventricular repolarization
Atrial repolarization is HIDDEN within the QRS complex (not seen as a separate wave)
Pulmonary ARTERY = deoxygenated blood (RV → lungs) — EXCEPTION to artery rule
Pulmonary VEIN = oxygenated blood (lungs → LA) — EXCEPTION to vein rule
Normal BP = 120/80 mmHg; hypertension = >140/90 mmHg ("silent killer")
Angina = temporary ischemia (reversible); MI = permanent cardiac cell death (irreversible)