Chapter 18

Assertion: Erythroblastosis feotalis not observed during first pregnancy although foetus is \(\mathrm{Rh}\) positive and mother is Rh negative. Reason: Rh antigens of foetus do not get exposed to Rh negative blood of mother in first pregnancy as the two bloods are well separated by placenta.

Assertion: Atria and ventricle do not contract simultaneously. Reason: It occurs due to \(\mathrm{AV}\) nodal delay.

Assertion: Starting of ventricular diastole leads to closure of semi lunar valves. Reason: Ventricular diastole leads to fall in ventricular pressure.

Assertion: If we cut nerve supply to human heart, there will be no effect on heart beat. Reason: Human heart is myogenic in nature.

Assertion: An injury or trauma stimulates the platelets to release certain factors which regulate the mechanism of coagulation. Reason: Calcium iron is very important for clotting of blood.

Assertion: The number of eosinophils increases in patients suffering from asthma. Reason: Asthma is an allergic disease.

Assertion: The disease erythroblastosis feotalis can be avoided in second pregnancy if Rh negative maternal blood exposed to Rh positive foetal blood during delivery of first child. Reason: If mother is administered with anti Rh antibodies immediately after the delivery of first child.