Life cycle of plasmodium
Plasmodium complete its life cycle in two different hosts.
1. Primary or definitive host
Female anopheles mosquito is a primary or definitive host where the sexual cycle of plasmodium
completes.
2. Secondary or intermediate host
Human is secondary or intermediate host where the asexual cycle of plasmodium occurs.
Asexual cycle ( Schizogony) in man
Plasmodium completes its asexual life cycle in three stages:
1. Liver schizogony
Liver schizogony completes in two phase
A. Pre- erythrocytic cycle (1st liver schizogony)
B. Exo-erythrocytic cycles( 2nd liver schizogony)
A. Pre- erythrocytic cycles ( 1st liver schizogony)
After the bite of infected mosquitoes, large number of sporozoites enter through blood
circulation and finally reach into the liver cells. They start to feed the content of liver cells and
grow into rounded schizont which divides by multiple fission to produce several spindle shaped
merozoites. Finally, host liver cells rupture and merozoites and liberated in the sinusoid of
liver, which are called cryptomerozoites. This asexual multiplication is called pre- erythrocytic
cycles. It is completed in about 8 to 10 days. This period is called pre- patent period ( a period
between inoculation and initiation of erythrocytic cycle)
Notes; Cryptomerozoites are immune to medicines.
B. Exo- erythrocytic cycle( 2nd liver schizogony)
It is second phase of asexual multiplication of plasmodium in the liver cell. Each
cryptomerozoites again invade fresh liver cell and grow into schizonts. Schizonts again
divide to merozoites, the merozoites thus produced are called metacryptomerozoites.
This second phase of asexual multiplication is called exo- erythrocytic cycle. These
meta cryptomerozoites are two types; smaller one are called micro
metacryptomerozoites ( attack fresh RBC) and larger are called macrometa
cryptomerozoites (attack liver cell to continue the exo- erythrocytic cycle)
NOTES; Exo- erythrocytic cycle is absent in Plasmodium falciparum.
Plasmodium complete its life cycle in two different hosts.
1. Primary or definitive host
Female anopheles mosquito is a primary or definitive host where the sexual cycle of plasmodium
completes.
2. Secondary or intermediate host
Human is secondary or intermediate host where the asexual cycle of plasmodium occurs.
Asexual cycle ( Schizogony) in man
Plasmodium completes its asexual life cycle in three stages:
1. Liver schizogony
Liver schizogony completes in two phase
A. Pre- erythrocytic cycle (1st liver schizogony)
B. Exo-erythrocytic cycles( 2nd liver schizogony)
A. Pre- erythrocytic cycles ( 1st liver schizogony)
After the bite of infected mosquitoes, large number of sporozoites enter through blood
circulation and finally reach into the liver cells. They start to feed the content of liver cells and
grow into rounded schizont which divides by multiple fission to produce several spindle shaped
merozoites. Finally, host liver cells rupture and merozoites and liberated in the sinusoid of
liver, which are called cryptomerozoites. This asexual multiplication is called pre- erythrocytic
cycles. It is completed in about 8 to 10 days. This period is called pre- patent period ( a period
between inoculation and initiation of erythrocytic cycle)
Notes; Cryptomerozoites are immune to medicines.
B. Exo- erythrocytic cycle( 2nd liver schizogony)
It is second phase of asexual multiplication of plasmodium in the liver cell. Each
cryptomerozoites again invade fresh liver cell and grow into schizonts. Schizonts again
divide to merozoites, the merozoites thus produced are called metacryptomerozoites.
This second phase of asexual multiplication is called exo- erythrocytic cycle. These
meta cryptomerozoites are two types; smaller one are called micro
metacryptomerozoites ( attack fresh RBC) and larger are called macrometa
cryptomerozoites (attack liver cell to continue the exo- erythrocytic cycle)
NOTES; Exo- erythrocytic cycle is absent in Plasmodium falciparum.
