Briefly describe the following (Any four):
$(a)$ Anaemia $(b)$ Angina Pectoris $(c)$ Atherosclerosis $(d)$ Hypertension $(e)$ Heart failure $(f)$ Erythroblastosis foetalis

(N/A) Anaemia: $A$ condition characterized by a deficiency of haemoglobin or red blood cells,leading to reduced oxygen-carrying capacity of the blood.
$(b)$ Angina Pectoris: $A$ symptom of acute chest pain occurring when not enough oxygen is reaching the heart muscle.
$(c)$ Atherosclerosis: $A$ condition where the arteries become narrowed due to the deposition of calcium,fat,cholesterol,and fibrous tissues.
$(d)$ Hypertension: High blood pressure,where the pressure is consistently higher than $120/80 \text{ mmHg}$.
$(e)$ Heart failure: $A$ state where the heart is not pumping blood effectively enough to meet the needs of the body.
$(f)$ Erythroblastosis foetalis: $A$ condition occurring in the foetus when $Rh$-negative mother carries an $Rh$-positive foetus,leading to the destruction of foetal red blood cells by maternal antibodies.