Explain The Life Cycle Of Plasmodium In Human Beings?

In human beings infective stage of plasmodium known as sporozoite occurs. These are transferred into the man by female mosquito through its salivary gland. It goes inside the liver and it enlarges it becomes round in shape. They are known as Schizont. They divide by multiple fission and form cryptozoites. This process is known as Schizogony. The cryptozoites are produced in the liver. There is a pre patent period which starts with the infection of sporozoite and extends till the first symptoms of parasites in blood appear. Its duration is of 8 days. After that cryptozoites enter other liver cells and multiply to form meta cryptozoites. This multiple fission that is schizogony also occurs in red blood corpuscles. It is known as erythrocytic schizogony. Than plasmodium passes through different stages such as signet ring stage, amoeboid stage and erythrocytic merozoites. When meta cryptozoites enter red blood cell they become round in shape known as young trophozoite. Than later on it forms a large contractile vacuole which pushes nucleus to one end. It gives a signet ring look to the trophozoite. After this trophozoite ring appearance it becomes amoebic in shape. It secretes enzyme lysolecithin which attacks the red blood cells cytoplasm. This leads to decomposition of hemoglobin to black haemozoin granules. Hemoglobin divides into haematin and globin. Globin is the protein part and haematin is the iron part. Haematin aggregates and globin helps in digestion of nutrition. There are yellow colored granules which occur in the cytoplasm of red blood cells are known as Schuffners dots. Trophozoite under goes mitotic division and it leads to formation of merozoites. Merozoites are released when red blood cells rupture. This leads to occurrence of fever. This time span in which fever is felt and sporozoite enter into human body is referred as incubation period. It varies from 12 to 28 days in different species of plasmodium. Restlessness, loss of appetite, muscular pains, and headache are the symptoms of malaria. These features are also accompanied by chills. They occur as the body temperature starts increasing. After two days the temperature gets normal. Merozoites enter inside the red blood cells and give rise to gametocytes. They can be small or large. Smaller one corresponds to male gametocytes also known as micro gametocytes. Larger ones respond to female gametocytes also known as macro gametocytes.