Q. 43. Describe the life cycle of malaria parasite?
The life cycle of malaria parasite :- There are two cycle in the life cycle of malaria parasite :-
A. Schizogony or asexual cycle in human the intermediate host.
B. Sporogony or sexual cycle in female anopheles mosquitoes the definitive host.
C. Schizogony or asexual cycle :- Schizogony in human starts with the introduction of sporozoites by the bite of the infected female anopheles mosquito schizogony has two phase :-
1. Exoerythrocytic phase that takes place in the parencymal cells of the liver.
Enyhthrocytic phase that takes place in the RBC Erythrocytic phase :- Sporozoites injected by the bite of the infected female anopheles mosquito. Will 1 hour they invade parencymal liver cells. Sporozoites divide by asexual fission and from exoerythrocytic schizons. Merozoite are formed within schizont. Each schizont contains about 30000 merozoites. Lever cell rupture and the merozoites leave the livercells, enter the blood stream and invade erythrocytes and the erythrocytic phase starts.
2. Erythrocytic phase : - In RBC merozoites ass through the stage of ring trophozoites, mature tropozoite immature schizoint, mature schizont having merozoites. Mature tropozoites feed on haemoglobin of the RBC and produce haemazoin, malarial pigment. Malarial parasites break out red cells synchronously. Each cycle of erythrocytic schizogony is completed in 48 hours with p. vivax 36-48 hours with p. falciparum. 48 hours with p. ovale and 72 hours with p. malariae.
The merozoites liberated into the circulation due to rupture of infected RBC enter freash red cells. A merozoites within the red blood cell may further develop into a ring tropozoite which leads to repetition of the erythrocytic cycle in all 4 species or may develop into a microgametocyte (male gametocyte) or a macro gametocyte (female gametocyte). This phase is called gametogony.
B. Sporogony or sexual cycle :- The sexual cycle of malaria parasite starts in the human host with the formation of gametocytes. Female anopheles mosquitoes ingest gametocytes within it takes blood meal of infected person. The gametocytes develop inside the stomach. From one microgametocyte, 4 to 8 microgamete are develop. From one macrogametocyte. only one macrogamete is formed. Fertilization takes place and zygote is formed. Zygote elongates to form an Okinete Ookinete enter in the wall of stomach and rests o the outer wall of the stomach. Here it divelops into oocyst. Ocyst grows and bursts to release sporozoites.
Sporozoites pass through body cavity and reach salivar4y gland of female anopheles mosquitoes. The sporozoites infect victim when the mosque bites and injects the sporozoites. The sporogony takes about 8 to 20 days.
The life cycle of malaria parasite :- There are two cycle in the life cycle of malaria parasite :-
A. Schizogony or asexual cycle in human the intermediate host.
B. Sporogony or sexual cycle in female anopheles mosquitoes the definitive host.
C. Schizogony or asexual cycle :- Schizogony in human starts with the introduction of sporozoites by the bite of the infected female anopheles mosquito schizogony has two phase :-
1. Exoerythrocytic phase that takes place in the parencymal cells of the liver.
Enyhthrocytic phase that takes place in the RBC Erythrocytic phase :- Sporozoites injected by the bite of the infected female anopheles mosquito. Will 1 hour they invade parencymal liver cells. Sporozoites divide by asexual fission and from exoerythrocytic schizons. Merozoite are formed within schizont. Each schizont contains about 30000 merozoites. Lever cell rupture and the merozoites leave the livercells, enter the blood stream and invade erythrocytes and the erythrocytic phase starts.
2. Erythrocytic phase : - In RBC merozoites ass through the stage of ring trophozoites, mature tropozoite immature schizoint, mature schizont having merozoites. Mature tropozoites feed on haemoglobin of the RBC and produce haemazoin, malarial pigment. Malarial parasites break out red cells synchronously. Each cycle of erythrocytic schizogony is completed in 48 hours with p. vivax 36-48 hours with p. falciparum. 48 hours with p. ovale and 72 hours with p. malariae.
The merozoites liberated into the circulation due to rupture of infected RBC enter freash red cells. A merozoites within the red blood cell may further develop into a ring tropozoite which leads to repetition of the erythrocytic cycle in all 4 species or may develop into a microgametocyte (male gametocyte) or a macro gametocyte (female gametocyte). This phase is called gametogony.
B. Sporogony or sexual cycle :- The sexual cycle of malaria parasite starts in the human host with the formation of gametocytes. Female anopheles mosquitoes ingest gametocytes within it takes blood meal of infected person. The gametocytes develop inside the stomach. From one microgametocyte, 4 to 8 microgamete are develop. From one macrogametocyte. only one macrogamete is formed. Fertilization takes place and zygote is formed. Zygote elongates to form an Okinete Ookinete enter in the wall of stomach and rests o the outer wall of the stomach. Here it divelops into oocyst. Ocyst grows and bursts to release sporozoites.
Sporozoites pass through body cavity and reach salivar4y gland of female anopheles mosquitoes. The sporozoites infect victim when the mosque bites and injects the sporozoites. The sporogony takes about 8 to 20 days.
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